Glossary of Terms


Term Definition

(All) level

The optional highest level of a dimension. The (All) level contains a single member that is the summary of all members of the immediately subordinate level.

.NET Framework

An integral Windows component that supports building, deploying, and running the next generation of applications and Web services. It provides a highly productive, standards-based, multilanguage environment for integrating existing investments with next generation applications and services, as well as the agility to solve the challenges of deployment and operation of Internet-scale applications. The .NET Framework consists of three main parts: the common language runtime, a hierarchical set of unified class libraries, and a componentized version of ASP called ASP.NET. See also: ASP.NET, common language runtime, .NET Framework class library.

acknowledged delivery

A positive confirmation from either the system or the recipient to SQL Server Notification Services that a notification has been delivered to the intended recipient.


An end-user-initiated operation on a selected cube or portion of a cube. The operation can launch an application with the selected item as a parameter or retrieve information about the selected item.

active statement

An SQL statement that has been run but whose result set has not yet been canceled or fully processed.

ActiveX Data Objects

An easy-to-use API that wraps OLE DB for use in languages such as Visual Basic, Visual Basic for Applications, Active Server Pages, and Microsoft Internet Explorer Visual Basic Scripting.

ActiveX Data Objects (Multidimensional) (ADO MD)

A high-level, language-independent set of object-based data access interfaces optimized for multidimensional data applications. Visual Basic and other automation languages use ADO MD as the data access interface to multidimensional data storage. ADO MD is a part of ADO 2.0 and later versions.

ad hoc report

An .rdl report created with Report Builder that accesses report models. Ad hoc reports include clickthrough functionality that allows report users to explore the data in the model.


A custom extension, written in any language that supports the Component Object Model (COM), that interacts with Analysis Manager and provides specific functionality. The most common language that is used for add-ins is Visual Basic. Add-ins are registered with the Analysis Add-in Manager. They are called by the Analysis Add-in Manager in response to user actions in the user interface.


See Other Term: application definition file


A control or status area that is attached to the edge of a pane or window, such as a toolbar or ruler.


A single value comprised of multiple values.

aggregate function

A function that performs a calculation on a column in a set of rows and returns a single value.

aggregate query

A query (SQL statement) that summarizes information from multiple rows by including an aggregate function such as Sum or Avg.


1. A table or structure that contains precalculated data for a cube. 2. A collection of objects that makes a whole. An aggregation can be a concrete or conceptual set of whole-part relationships among objects.

aggregation prefix

A string that is combined with a system-defined ID to create a unique name for a partition's aggregation table.

aggregation usage

A cube attribute property that determines whether an attribute will be considered a candidate for an aggregation.


A user-defined response to a SQL Server event. Alerts can either run a defined task , or they can send an e-mail or pager message to a specified operator.


An alternative name for a table or column in expressions that is often used to shorten the name for subsequent reference in code, prevent possible ambiguous references, or provide a more descriptive name in the query output. An alias can also be an alternative name for a server.


A condition that exists when an index is built on the same partition scheme as its corresponding table.

allocation unit

A set of pages that can be operated on as a whole. Pages that belong to an allocation unit are tracked by Index Allocation Map (IAM) pages. An allocation unit is made up of the IAM-page chain and all the pages marked as allocated in that IAM page chain. An allocation unit can contain only one IAM chain, and an IAM chain must belong to only one allocation unit.

Analysis server

The server component of Analysis Services that is specifically designed to create and maintain multidimensional data structures and provide multidimensional data in response to client queries.


A member in a superior level in a dimension hierarchy that is related through lineage to the current member within the dimension hierarchy.

annotational property

A property that is maintained by Metadata Services as string data that can be attached to any repository object that exposes the IAnnotationalProps interface.

anonymous subscription

A type of pull subscription for which detailed information about the subscription and the Subscriber is not stored.


See Other Term: application programming interface

API server cursor

A server cursor that is built to support the cursor functions of an API, such as ODBC, OLE DB, ADO, and DB-Library. An application does not usually request a server cursor directly. Instead, it calls the cursor functions of the API. The SQL Server interface for that API implements a server cursor if that is the best way to support the requested cursor functionality.


An individual solution for matching events with subscriptions, and then formatting and delivering the resulting notifications.

application database

The database that stores user and system data for one application. The application database contains the events, subscriptions, and notifications for the application. It also contains system metadata, including the schemas for the events, subscriptions, and notifications for the application; and the match rules for the application.

application definition file

An XML file that fully describes a single Notification Services application. The ADF contains the schemas for the events, subscriptions, and notifications; and the rules for matching events with subscriptions. The ADF might also provide the name of the XSLT file that is used to format generated notifications.

application programming interface

A set of routines available in an application, such as ADO, for use by software programmers when designing an application interface.

application role

A SQL Server role created to support the security needs of an application.

archive file

The .cab file created by archiving an Analysis Services database.


A value that provides information to an action, an event, a method, a property, a function, or a procedure.


Identifies a database object that is included in a publication. A publication can contain different types of articles, including tables, views, stored procedures, and other objects. When tables are published as articles, filters can be used to restrict the columns and rows of the data sent to Subscribers.


A managed application module that contains class metadata and managed code as an object in SQL Server. By referencing an assembly, common language runtime (CLR) functions, CLR stored procedures, CLR triggers, user-defined aggregates, and user-defined types can be created in SQL Server.


Either all of the transaction data modifications are performed or none of them are performed.


1. In an Analysis Services dimension, a single characteristic of a measure. 2. In an Analysis Services mining model, a single characteristic of a case. 3. In Report Builder, a field in an entity, defined by the Attribute object in Model Designer.

attribute hierarchy

A hierarchy of attribute members that contains the following levels: A leaf level that contains each distinct attribute member, with each member of the leaf level also known as a leaf member; intermediate levels if the attribute hierarchy is a parent-child hierarchy; and an optional (All) level that contains the aggregated value of the attribute hierarchy's leaf members, with the member of the (All) level also known as the (All) member. By default, an attribute hierarchy is defined for each dimension attribute. Attribute hierarchies are visible by default.

attribute relationship

A one-to-many relationship between attributes, such as the relationship between a state dimension attribute and a city dimension attribute.

automatic failover

A failover that is initiated by the mirror server after the principal server is disconnected from both the mirror server and the witness. Assuming that the mirror database is already synchronized with the principal database, the mirror server takes over the role of principal server and brings its copy of the database online as the principal database.

automatic recovery

Recovery that occurs every time SQL Server is restarted. Automatic recovery helps protect the database if there is a system failure.


The independence of one site from other sites when performing modifications to data.


A set of tuples. Each tuple is a vector of members. A set of axes defines the coordinates of a multidimensional data set.

back up

To create a backup copy of a database, filegroup, file, or transaction log.


A specialized copy of a database, filegroup, file, or transaction log that can be used by SQL Server to restore database data, typically after a serious database error or a system failure. Backups can be restored individually, or a set of backups can be restored in sequence.

backup device

A tape or disk drive that contains backup media.

backup file

A file that stores a SQL Server backup of a full or partial database; file, filegroup, or both; or transaction log.

backup media

Disk files or tapes that are used to hold one or more backups.

backup set

A single backup within a media set. Each backup set is distributed among all the media families of the media set.

balanced hierarchy

A dimension hierarchy in which all leaf nodes are the same distance from the root node.

base table

A table stored permanently in a database. Base tables are referenced by views, cursors, SQL statements, and stored procedures.


1. A set of SQL statements submitted together and runas a group. A script is often a series of batches submitted one after the other. 2. In Reporting Services, a collection of SOAP method calls within a single transaction.

bcp files

Files that store bulk copy data created by the bulk copy utility or by synchronization between a Publisher and its Subscribers.

binary large object

A piece of binary data that has an exceptionally large size, such as pictures or audio tracks that are stored as digital data, or any variable or table column that is large enough to hold such values. In Transact-SQL, a binary large object (BLOB) is stored in an image column. Sometimes the term BLOB is also applied to large character data values, such as those stored in text or ntext columns.


1. In SQL Server APIs, binding is associating a result set column or a parameter with a program variable so that data is moved automatically into or out of a program variable when a row is fetched or updated. 2. In Analysis Services, a defined relationship between an attribute or a measure and one or more underlying columns in a dimension or fact table.

bitwise operation

An operation that manipulates a single bit, or tests whether a bit is on or off.


A series of Transact-SQL statements enclosed by BEGIN and END. You can nest BEGIN...END blocks within other BEGIN...END blocks.


A link in a report that jumps to another place within the report.


An operation or expression that can be evaluated only as either true or false.


A program that installs or runs other programs.

browse mode

A function that lets you scan database rows and update their values one row at a time. Several browse mode functions return information that an application can use to examine the structure of a complicated ad hoc query.

built-in functions

A group of predefined functions provided as part of the Transact-SQL and Multidimensional Expressions (MDX) languages.

bulk export

To copy a large set of data rows from a SQL Server table into a data file.

bulk import

To load a large set of data rows from a data file into a SQL Server table. The Database Engine applies logging and locking optimizations when it is possible.

bulk-logged recovery model

A database recovery mode that minimally logs bulk operations, such as index creation and bulk imports, while fully logging other transactions. Bulk-logged recovery increases performance for bulk operations and is intended to be used as an adjunct to the full recovery model.

business logic handler

A merge replication feature that allows you to run custom code during the synchronization process.

business rules

The logical rules that are used to run a business. Business rules can be enforced in a SQL Server database by using triggers, stored procedures, and constraints.

calculated column

A column in a table that displays the result of an expression rather than stored data. For example, CalculatedCostColumn = Price * Quantity.

calculated field

A field defined in a query that displays the result of an expression rather than stored data.

calculated member

A member of a dimension whose value is calculated at run time by using an expression. Calculated member values can be derived from the values of other members. A calculated member is any member that is not an input member. For example, a calculated member, Profit, can be determined by subtracting the value of the member Costs, from the value of the member Sales.

calculation condition

A Multidimensional Expressions (MDX) logical expression that is used to determine whether a calculation formula will be applied against a cell in a calculation subcube.

calculation formula

A Multidimensional Expressions (MDX) expression used to supply a value for cells in a calculation subcube, subject to the application of a calculation condition.

calculation pass

A stage of calculation in a multidimensional cube in which applicable calculations are evaluated. Multiple passes may be required to complete all calculations.

calculation subcube

The set of multidimensional cube cells that is used to create a calculated cells definition. The set of cells is defined by a combination of Multidimensional Expressions (MDX) set expressions.

candidate key

A column or set of columns that have a unique value for each row in a table. Each candidate key value uniquely identifies a single row in the table. Tables can have multiple candidate keys. One candidate key in a table is specified by the database designer to be the primary key for the table, and any other candidate key is called an alternate key.

cascading delete

An operation that deletes a row containing a primary key value that is referenced by foreign key columns in existing rows in other tables. On a cascade delete, all of the rows whose foreign key values reference the deleted primary key value are also deleted.

cascading parameters

Parameters that derive their available values from the selection of a preceding parameter. Cascading parameters are used to filter a set of parameter values.

cascading update

An operation that updates a primary key value that is referenced by foreign key columns in existing rows in other tables. On a cascade update, all the foreign key values are updated to match the new primary key value.


In data mining, an abstract view of data characterized by attributes and relations to other cases. A case is a distinct member of a case set, and can be a member of multiple case sets.

case key

In data mining, the element of a case by which the case is referenced within a case set.

case set

In data mining, a group of cases that share characteristics required by a particular mining model.


In a cube, the set of properties, including a value, specified by the intersection when one member is selected from each dimension.


In ADO MD, an object that contains a collection of cells selected from cubes or other cellsets by a multidimensional query.

change script

A text file that contains SQL statements for all changes made to a database, in the order in which they were made, during an editing session. Each change script is saved in a separate text file with an .sql extension. Change scripts can be applied back to the database later, using a tool such as osql.

changing dimension

A dimension that has a flexible member structure. A changing dimension is designed to support frequent changes to structure and data.

character format

Data stored in a bulk copy data file using text characters.

character set

Determines the types of characters that SQL Server recognizes in the char, varchar, and text data types. Each character set is a set of 256 letters, digits, and symbols specific to a country or language. The printable characters of the first 128 values are the same for all character sets. The last 128 characters, sometimes referred to as extended characters, are unique to each character set. A character encoding, such as Unicode, is a way of mapping a given character in a language to an integrer value in a character set.

chart data region

A report item on a report layout that displays data in a graphical format.

CHECK constraints

Defines which data values are acceptable in a column. You can apply CHECK constraints to multiple columns, and you can apply multiple CHECK constraints to a single column. When a table is dropped, CHECK constraints are also dropped.


An event in which the Database Engine writes dirty buffer pages to disk. Each checkpoint writes to disk all the pages that were dirty at the last checkpoint and still have not been written to disk. Checkpoints occur periodically based on the number of log records that are generated by data modifications, or when checkpoints are requested by a user or a system shutdown.


A member in the next lower level in a hierarchy that is directly related to the current member.

child package

In Integration Services, a package that is run by another package. A child package is also known as the called package.


A table that stores state information for a single application. An example is an event chronicle, which can store event data for use with scheduled subscriptions.


See Other Term: call-level interface

clickthrough report

A report that displays related report model data when you click data within a rendered Report Builder report.

client application

An application that retrieves data from a server and performs local analysis and presentation of data from relational or multidimensional databases.

client cursor

A cursor that is implemented on the client. The entire result set is first transferred to the client, and the client API software implements the cursor functionality from this cached result set.

client subscription

A subscription to a merge publication that uses the priority value of the Publisher for conflict detection and resolution. Referred to as a local subscription in previous versions of SQL Server.


See Other Term: common language runtime

CLR function

A function that is created by referencing a SQL Server assembly. The implementation of the CLR function is defined in an assembly that is created in the .NET Framework common language runtime (CLR).

CLR stored procedure

A stored procedure that is created by referencing a SQL Server assembly. The implementation of the CLR stored procedure is defined in an assembly that is created in the .NET Framework common language runtime (CLR).

CLR trigger

A DML trigger or DDL trigger that is created by referencing a SQL Server assembly. The implementation of the CLR trigger is defined in an assembly that is created in the .NET Framework common language runtime (CLR).

CLR user-defined type

A user-defined data type that is created by referencing a SQL Server assembly. The implementation of the CLR user-defined type is defined in an assembly that is created in the .NET Framework common language runtime (CLR).

clustered index

An index in which the logical order of the key values determines the physical order of the corresponding rows in a table. In a clustered index, the leaf nodes contain the data pages of the underlying table.


A data mining technique that analyzes data to group records together according to their location within the multidimensional attribute space. Clustering is an unsupervised learning technique.

code access security

A mechanism provided by the common language runtime whereby managed code is granted permissions by security policy and these permissions are enforced, helping to limit the operations that the code will be allowed to perform.

code page

For character and Unicode data, a definition of the bit patterns that represent specific letters, numbers, or symbols (such as 0x20 representing a blank space and 0x74 representing the character "t"). Some data types use 1 byte per character; each byte can have 1 of 256 different bit patterns.


A set of rules that determines how data is compared, ordered, and presented. Character data is sorted using collation information, including locale, sort order, and case-sensitivity.


An object that contains a set of other objects. An object's position in the collection can change whenever a change occurs in the collection; therefore, the position of any specific object in the collection may vary.


In an SQL table, the area in each row that stores the data value for some attribute of the object modeled by the table. For example, the Employee table in the AdventureWorks sample database models the employees of the Adventure Works Cycles company. The Title column in each row of the Employee table stores the job title of the employee represented by that row, the same way a Job Title field in a window or form would contain a job title.

column binding

The binding of an Analysis Services object to a column in a data source view.

column filter

Column filters restrict the columns to be included as part of a snapshot, transactional, or merge publication.

column-level collation

Supporting multiple collations in a single instance. Databases can have default collations different from the default collation of the instance. Individual columns and variables can be assigned collations different from the default collation for the instance or database. Each column in a table can have a different collation.

column-level constraint

A constraint definition that is specified within a column definition when a table is created or altered. The constraint applies only to the associated column.


See Other Term: Component Object Model


In transactional replication, a command consists of one Transact-SQL data manipulation language (DML) statement or one data definition language (DDL) statement. Commands are stored in the distribution database and then delivered to Subscribers.

command relationship

Provides instructions to hardware based on natural-language questions or commands. For example, "Play the album with song 'Song' on it."


An operation that saves all changes to databases, cubes, or dimensions made since the start of a transaction. A commit guarantees that all of the transaction's modifications are made a permanent part of the database, cube or dimension. A commit also frees resources, such as locks, used by the transaction.

common language runtime

The engine at the core of managed code execution. The runtime supplies managed code with services such as cross-language integration, code access security, object lifetime management, and debugging and profiling support.

complete database restore

A restore of a full database backup, the most recent differential database backup (if any), and the log backups (if any) taken since the full database backup.

component (Notification Services)

Within Notification Services, a component is a major element of the Notification Services platform. These include the event collector, the generator, the distributor, and the vacuumer.

Component Object Model

A Microsoft specification for developing component software. Several SQL Server and database APIs such as SQL-DMO, OLE DB, and ADO are based on COM. Some SQL Server components store objects as COM objects.

composite index

An index that uses more than one column in a table to index data.

composite key

A key composed of two or more columns.

computed column

A virtual column in a table whose value is computed at run time. The values in the column are not stored in the table, but are computed based on the expression that defines the column. An example of the definition of a computed column is: Cost as Price * Quantity.

computed field

A value in a formatted notification that has been computed by using a Transact-SQL expression.


To combine two or more character strings or expressions into a single character string or expression, or to combine two or more binary strings or expressions into a single binary string or expression.


A process that allows multiple users to access and change shared data at the same time. SQL Server uses locking to allow multiple users to access and change shared data at the same time without conflicting with each other.

configuration file (Notification Services)

An XML file that contains the configuration data for an instance of Notification Services. The configuration file specifies the applications that are hosted by the instance, the name of the database server, the database properties, and the delivery protocols and delivery channels.


In Integration Services, a name/value pair that updates the value of package objects when the package is loaded.


An interprocess communication (IPC) linkage established between a SQL Server application and an instance of SQL Server. The connection is a network link if the application is on a computer different from the SQL Server instance. If the application and the SQL Server instance are on the same computer, the linkage is formed through a local IPC mechanism, such as shared memory. The application uses the IPC linkage to send Transact-SQL statements to SQL Server and to receive result sets, errors, and messages from SQL Server.

connection manager

In Integration Services, a logical representation of a run-time connection to a data source.


A group of symbols that represent a specific data value. The format of a constant depends on the data type of the value it represents. For example, 'abc' is a character string constant, 123 is an integer constant, 'December 16, 1999' is a datetime constant, and 0x02FA is a binary constant.


A property assigned to a table column that prevents certain types of invalid data values from being placed in the column. For example, a UNIQUE or PRIMARY KEY constraint prevents you from inserting a value that is a duplicate of an existing value, a CHECK constraint prevents you from inserting a value that does not match a specified condition, and NOT NULL prevents you from inserting a NULL value.


In Integration Services, a package, Foreach Loop, For Loop, Sequence, task, or event handler.

content formatter (Notification Services)

The part of the Distributor that turns raw notification data into readable messages.

continuation tape

A backup tape that allows for continuation after the first backup tape in a media family.

control-of-flow language

Transact-SQL keywords that control the flow of execution of SQL statements and statement blocks in triggers, stored procedures, and batches.

correlated subquery

A subquery that references a column in the outer statement. The inner query is run for each candidate row in the outer statement.

CPU busy

A SQL Server statistic that reports the time, in milliseconds, that the central processing unit (CPU) spent on SQL Server work.


See Other Term: population


Data used by a principal to establish the identity of the principal, such as a password or user name.


A set of data that is organized and summarized into a multidimensional structure defined by a set of dimensions and measures.

cube granularity

The space in a cube that is defined by the cross-join of a single level from each and every attribute hierarchy.

cube role

A collection of users and groups with the same access to a cube. A cube role is created when you assign a database role to a cube, and it applies only to that cube.


An entity that maps over a result set and establishes a position on a single row within the result set. After the cursor is positioned on a row, operations can be performed on that row, or on a block of rows starting at that position. The most common operation is to fetch (retrieve) the current row or block of rows.

cursor degradation

See Other Term: implicit cursor conversion

cursor library

A part of the ODBC and DB-Library APIs that implements client cursors. A cursor library is not commonly used in current systems; server cursors are used instead.

custom rollup

An aggregation calculation that is customized for a dimension level or member, and that overrides the aggregate functions of a cube's measures.

custom rule

In a role, a specification that limits the dimension members or cube cells that users in the role are permitted to access.

data backup

Any backup that includes the full image of one or more data files.

data block

1. In text, ntext, and image data, a data block is the unit of data transferred at one time between an application and an instance of SQL Server. The term is also applied to the units of storage for these data types. 2. In tape backup files, data block is the unit of physical I/O.

data connection

A collection of information that is required to access a specific database. The collection includes a data source name and logon information. Data connections are stored in a project and are activated when the user performs an action that requires access to the database. For example, a data connection for a SQL Server database consists of the name of the database, the location of the server on which it resides, the network information that is used to access that server, and a user ID and password.

data definition

Specifying the attributes, properties, and objects in a database.

data definition language

The subset of SQL statements that define all attributes and properties of a database and its objects. DDL statements typically start with CREATE, ALTER, or DROP.

data dictionary

A set of system tables, stored in a catalog, that includes definitions of database structures and related information, such as permissions.

data dictionary view

A system table.

data explosion

The exponential growth in size of a multidimensional structure, such as a cube, due to the storage of aggregated data.

data file

In bulk import and export operations, the file that receives data from a bulk export operation or provides data to a bulk export operation. In SQL Server databases, data files hold the data stored in the database. Every SQL Server database has at least one primary data file and can optionally have multiple secondary data files to hold data that does not fit on the primary data file.

data flow

The ordered workflow in an Integration Services package that extracts, transforms, and loads data.

data integrity

A state in which all the data values stored in the database are correct. If incorrect data values have been stored in a database, the database is said to have lost data integrity.

data manipulation language

The subset of SQL statements that is used to retrieve and manipulate data. DML statements typically start with SELECT, INSERT, UPDATE, or DELETE.

data mart

A subset of the contents of a data warehouse. A data mart tends to contain data focused at the department level, or on a specific business area.

data member

A child member associated with a parent member in a parent-child hierarchy. A data member contains the data value for its parent member, rather than the aggregated value for the parent's children.

data modification

An operation that adds, deletes, or changes information in a database using Transact-SQL statements such as INSERT, DELETE, and UPDATE.

data processing extension

A component in Reporting Services that is used to retrieve report data from an external data source. Data processing extensions can include special-purpose query designers that make it easier to work with data in Report Designer. Examples of some default data processing extensions include Microsoft SQL Server, Analysis Services, Oracle, and SAP NetWeaver Business Intelligence.

data pump

A component used in SQL Server 2000 Transformation Services (DTS) to import, export, and transform data between heterogeneous data stores. In SQL Server 2005, this component was replaced by the Data Flow task and the data flow components.

data region

A report item that displays repeated rows of data from an underlying dataset in a table, matrix, list, or chart.

data scrubbing

Part of the process of building a data warehouse out of data coming from multiple online transaction processing (OLTP) systems. The process must address errors such as incorrect spellings, conflicting spelling conventions between two systems, and conflicting data (such as having two part numbers for the same part).

data source

1. In ADO and OLE DB, the location of a source of data exposed by an OLE DB provider. 2. The source of data for an object such as a cube or dimension. It is also the specification of the information necessary to access source data. It sometimes refers to an object of ClassType clsDataSource. 3. In Reporting Services, a specified data source type, connection string, and credentials, which can be saved separately to a report server and shared among report projects or embedded in a report definition (.rdl) file.

data source name

The name assigned to an ODBC data source. Applications can use DSNs to request a connection to a system ODBC data source, which specifies the computer name and, optionally, the database to which the DSN maps.

data source view

A named, browsable, persisted selection of database objects that can be used as a data source by multiple projects.

data type

An attribute that specifies what type of information can be stored in a column, parameter, or variable. System-supplied data types are provided by SQL Server. Alias data types can also be created.

data warehouse

A database specifically structured for query and analysis. A data warehouse typically contains data representing the business history of an organization.


A collection of information, tables, and other objects organized and presented to serve a specific purpose, such as searching, sorting, and recombining data. Databases are stored in files.

database backup

A backup of every data file in a database. A full database backup contains all the data in every file.

database catalog

The part of a database that contains the definition of all the objects in the database, as well as the definition of the database.

database diagram

A graphical representation of the objects in a database. A database diagram can be either a whole or a partial picture of the structure of a database. It includes objects for tables, the columns that they contain, and the relationship between them.

database file

One of the physical files that make up a database.

database language

The language used for accessing, querying, updating, and managing data in relational database systems. SQL is a widely used database language. The Microsoft SQL Server implementation of SQL is called Transact-SQL.

database mirroring

The process of immediately reproducing every update to a read/write database (the principal database) onto a read-only mirror of that database (the mirror database) that resides on a separate instance of the Database Engine (the mirror server).

database mirroring partners

Two server instances that act as role-switching partners for a mirrored database.

database object

A database component, such as a table, index, trigger, view, key, constraint, default, rule, user-defined data type, or stored procedure in a database. Can also refer to the database itself.

database owner

A member of the database administrator role of a database. There is only one database owner. The owner has full permissions in that database and determines the access and capabilities provided to other users.

database project

A collection of one or more data connections (a database and the information needed to access that database). When you create a database project, you can connect to one or more databases through ODBC and view their components through a visual user interface that includes a Database Designer for designing and creating databases and a Query Designer for creating SQL statements for any ODBC-compliant database.

database role

A collection of users and groups with the same access to an Analysis Services database. You can assign a database role to multiple cubes in the database, thereby granting the role's users access to these cubes.

database schema

The names of tables, fields, data types, and primary and foreign keys of a database. Also known as the database structure.

database script

A collection of statements used to create database objects. Transact-SQL scripts are saved as files, usually ending with .sql.

database snapshot

A read-only, static view of a database at the moment of snapshot creation.

data-definition query

An SQL query that contains data definition language (DDL) statements. These are statements that allow you to create or alter objects (such as tables, indexes, views, and so on) in the database and to migrate database objects from Microsoft Access.

data-driven subscription

A subscription in Reporting Services that uses a query to retrieve subscription data from an external data source at run time.


A stream of data that is returned by an ADO.NET query. The DataReader object enables a client to receive a read-only, forward-only stream of data.


1. In OLE DB for OLAP, the set of multidimensional data that is the result of running a Multidimensional Expressions (MDX) SELECT statement. 2. In Reporting Services, a named specification that includes a data source definition, a query definition and optional parameter values, calculated fields, and filtering and collation information as part of a report definition (.rdl) file. An .rdl file can have multiple datasets.


See Other Term: double-byte character set


See Other Term: database owner


See Other Term: Data Control Language


See Other Term: data definition language

DDL trigger

A trigger that fires in response to data definition language (DDL) statements.


A situation when two users, each having a lock on one piece of data, attempt to acquire a lock on the other's piece. Each user would wait indefinitely for the other to release the lock, unless one of the user processes is terminated. SQL Server detects deadlocks and terminates one user's process.

decision support

Systems designed to support the complex analytic analysis required to discover business trends. The information retrieved from these systems allows managers to make business decisions based on timely and accurate analysis of business trends.

decision tree

A treelike model of data produced by certain data mining methods. Decision trees can be used for prediction.

declarative referential integrity

FOREIGN KEY constraints defined as part of a table definition that enforce proper relationships between tables. The constraints ensure that proper actions are taken when DELETE, INSERT, and UPDATE statements remove, add, or modify primary or foreign key values. The DRI actions enforced by FOREIGN KEY constraints can be supplemented with additional referential integrity logic defined in triggers on a table.


A data value, option setting, collation, or name assigned automatically by the system if a user does not specify the value, setting, collation, or name. An action taken automatically at certain events if a user has not specified the action to take.

DEFAULT constraint

A property defined for a table column that specifies a constant to be used as the default value for the column. If any subsequent INSERT or UPDATE statement specifies a value of NULL for the column, or does not specify a value for the column, the constant value defined in the DEFAULT constraint is placed in the column.

default database

The database the user is connected to immediately after logging in to SQL Server.

default instance

The instance of SQL Server that uses the same name as the computer name on which it is installed.

default language

The language that SQL Server uses for errors and messages if a user does not specify a language. Each SQL Server login has a default language.

default member

The dimension member used in a query when no member is specified for the dimension. The default member of a dimension is the All member if an (All) level exists, or else an arbitrary member of the highest level. You can also set default members for individual roles in custom rules for dimension security.

default result set

The default mode that SQL Server uses to return a result set back to a client. Rows are sent to the client in the order in which they are placed in the result set, and the application must process the rows in this order. After running an SQL statement on a connection, the application cannot do anything on the connection except retrieve the rows in the result set until all the rows have been retrieved. The only other action that an application can perform before the end of the result set is to cancel the remainder of the result set. This is the fastest method to get rows from SQL Server to the client.

deferred transaction

A transaction that is not committed when the roll forward phase of recovery finishes, and that cannot be rolled back during database startup because the data required by rollback is offline. This data can reside in either a page or a file.

Delete query

A query (SQL statement) that removes rows from one or more tables.


1. In Transact-SQL, characters that indicate the start and end of an object name, by using either double quotation marks ("") or brackets ([]). 2. In Integration Services and Reporting Services, characters that are used to separate records, fields, or strings.

delivery channel

A pipeline between a Distributor and a delivery service.

delivery channel instance

A single occurrence of a delivery channel.

delivery channel type

The protocol for a delivery channel, such as Simple Mail Transfer Protocol (SMTP) or File.

delivery extension

A component in Reporting Services that is used to distribute a report to specific devices or target locations. Examples of actual and potential delivery extensions include e-mail delivery, shared folder delivery, printer delivery, or application delivery (such as a document management system).

delivery protocol

The set of communication rules used to route notification messages to external delivery systems.


To introduce redundancy into a table to incorporate data from a related table. The related table can then be eliminated. Denormalization can improve efficiency and performance by reducing complexity in a data warehouse schema.


In an index, the frequency of duplicate values. In a data file, a percentage that indicates how full a data page is. In Analysis Services, the percentage of cells that contain data in a multidimensional structure. Analysis Services stores only cells that contain data. A dense cube requires more storage than a sparse cube of identical structure and design.


The objects that depend on other objects in the database. For example, a stored procedure might depend on a table, a view, or on another stored procedure.


A member in a dimension hierarchy that is related to a member of a higher level within the same dimension. For example, in a Time dimension containing the levels Year, Quarter, Month, and Day, January is a descendant of 1997.


An Integration Services data flow component that writes the data from the data flow into a data source or creates an in-memory dataset.

destination device (Notification Services)

A delivery location (hardware or application) to which notifications are sent.

device name

A user-defined description of a particular device, used in conjunction with the Subscriber ID to identify a specific Subscriber device. A device name must be provided to the notification function as an input parameter.

device type

A value from a developer-defined list that specifies the types of devices that a given application will support. A device type corresponds to a single delivery channel.

differential backup

A backup that contains only the changes that were made since the creation of its differential base or bases. A differential backup can be taken for a whole database or any subset of data files for which a base exists.

differential base

The most recent full backup of all the data in a database or in a subset of the files or filegroups of a database.

digest delivery (Notification Services)

A method of sending notifications that combines multiple notifications within a batch and sends the resulting message to a Subscriber.


A structural attribute of a cube, which is an organized hierarchy of categories (levels) that describe data in the fact table. These categories typically describe a similar set of members upon which the user wants to base an analysis. For example, a geography dimension might include levels for Country, Region, State or Province, and City.

dimension table

A table in a data warehouse whose entries describe data in a fact table. Dimension tables contain the data from which dimensions are created.

dimension type

Specifies the type of information contained by the dimension, such as time information, which may enable specific treatment by the server and client applications.

direct connect

The state of being connected to a back-end database, so that any changes you make to a database diagram automatically update your database when you save the diagram or selected items in it.

direct response mode

The default mode in which SQL Server statistics are gathered separately from the SQL Server Statistics display. Data is available immediately to SQL Server Performance Monitor; however, the statistics displayed are one period behind the statistics retrieved.

dirty pages

Buffer pages that contain modifications that have not been written to disk.

dirty read

Reads that contain uncommitted data. For example, transaction1 changes a row. Transaction2 reads the changed row before transaction1 commits the change. If transaction1 rolls back the change, transaction2 has read a row that never logically existed.


An automatic grouping of attribute hierarchy members.

display folder

A folder into which attributes, measures, calculated members, and KPIs can be organized to facilitate browsing by users.


To move transactions or snapshots of data from the Publisher to Subscribers, where they are applied to the destination tables in the subscription databases.

distributed partitioned view

A view that joins horizontally partitioned data from a set of member tables that exist across more than one server. The data appears as if it is in one table.

distributed query

A single query that accesses data from multiple data sources.

distributed transaction

A transaction that spans multiple data sources. In a distributed transaction, all data modifications in all accessed data sources are either committed or terminated.

distribution database

A database on the Distributor that stores metadata and history data for all types of replication and transactions for transactional replication.

distribution retention period

In transactional replication, the amount of time transactions are stored in the distribution database. Also referred to as the transaction retention period.


A database instance that acts as a store for replication specific data associated with one or more Publishers. Each Publisher is associated with a single database (known as a distribution database) at the Distributor.

Distributor (Notification Services)

The component of Notification Services that formats notifications and sends them to external delivery services.


See Other Term: dynamic management function


See Other Term: data manipulation language

DML trigger

A stored procedure that executes when data in a specified table is modified. Triggers are often created to enforce referential integrity or consistency among logically related data in different tables.


See Other Term: dynamic management view

document map

A navigation pane in a report arranged in a hierarchy of links to report sections and groups.


1. In Windows security, a collection of computers grouped for viewing and administrative purposes that share a common security database. 2. In relational databases, the set of valid values allowed in a column.

domain integrity

An integrity mechanism that enforces the validity of entries for a given column. The mechanism, such as the CHECK constraint, can restrict the possible data values by data type, format, or range of values allowed.

double-byte character set

A character set that generally uses two bytes to represent a character, allowing more than 256 characters to be represented. DBCSs are typically used in environments that use ideographic writing systems, such as Japanese, Korean, and Chinese.

download-only article

An article in a merge publication that can be updated only at the Publisher or at a Subscriber that uses a server subscription.


See Other Term: declarative referential integrity

drill down/drill up

A technique for navigating through levels of data ranging from the most summarized (up) to the most detailed (down). For example, when viewing the details of sales data by year, a user can drill down to display sales data by quarter, and further to display data by month.

drill through

1. In Analysis Services, to retrieve the detailed data from which the data in a cube cell was summarized. 2. In Reporting Services, to open related reports by clicking hyperlinks in the main drillthrough report.

drillthrough report

A report with the 'enable drilldown' option selected. Drillthrough reports contain hyperlinks to related reports.


See Other Term: data source name

DSN-less connection

A type of data connection that is created based on information in a data source name (DSN), but is stored as part of a project or application. DSN-less connections are especially useful for Web applications because they let you move the application from one server to another without re-creating the DSN on the new server.

dynamic cursor

A cursor that can reflect data modifications made to the underlying data while the cursor is open. Updates, deletes, and inserts made by users are reflected in the dynamic cursor.

dynamic filter

See Other Term: parameterized row filter

dynamic locking

The process used by SQL Server to determine the most cost-effective locks to use at any one time.

dynamic management function

A set of built-in functions that return server state information about values, objects, and settings in SQL Server. These views that can be used to monitor the health of a server instance, diagnose problems, and tune performance.

dynamic management view

A set of built-in views that return server state information about values, objects, and settings in SQL Server. These views that can be used to monitor the health of a server instance, diagnose problems, and tune performance.

dynamic recovery

The process that detects and/or attempts to correct software failure or loss of data integrity within a relational database management system (RDBMS).

dynamic snapshot

See Other Term: partitioned snapshot

dynamic SQL statements

In Embedded SQL for C, an SQL statement built and executed at run time.


A method for keeping sensitive information confidential by changing data into an unreadable form.

entity integrity

A state in which every row of every table can be uniquely identified. Entity integrity is usually enforced by a PRIMARY KEY constraint, a UNIQUE constraint, or a UNIQUE index.


A fixed set of integer values or string constants that may be used to specify the value of certain properties.


A join in which the values in the columns being joined are compared for equality, and all columns are included in the results.

error log

1. In SQL Server, a text file that records system information. 2. In Integration Services, a record of errors, warnings or events, which can be stored by multiple log providers, including SQL Server Profiler, the Windows Event log, and SQL Server.

error state number

A number associated with SQL Server messages that helps Microsoft support engineers find the specific code location that issued the message. This can be helpful in diagnosing errors that might be generated from different locations in the SQL Server code.

escape character

A character used to indicate that another character in an expression is meant literally and not as an operator. For example, in SQL, the character "%" is used as a wildcard character to mean "any number of characters in this position." However, if you want to search for a string such as "10%" (ten percent), you cannot specify "10%" alone as a search string, because the "%" would be interpreted as "any number of characters in addition to 10." By specifying an escape character, you can flag instances where "%" specifically means percent. For example, if you specify the escape character "#", you can indicate a search string of "10#%" to mean "ten percent."


Extraction, transformation, and loading. The complex process of copying and cleaning data from heterogeneous sources. Important part of development projects for data warehousing and business intelligence.


An action or occurrence, often generated by the user, to which a program might respond.

event batch (Notification Services)

A set of one or more events submitted to Notification Services at one time.

event chronicle

A table that stores event state information.

event chronicle rule

One or more Transact-SQL statements that manage the data in the event chronicle. This type of rule is fired each time an event batch for the rule's event class is submitted to the system.

event class

A single class defined by one EventClass node in an application definition file. An EventClass node defines the structure and properties of a particular type of event. Note that EventClass is a placeholder for the actual name of the event class.

event collection stored procedures

System-generated stored procedures that an application can call to submit events to the event table in the application database. These stored procedures can be called from SQL Server triggers or other SQL Server stored procedures.

event handler

In Integration Services, a control flow that runs in response to a run-time event.

event notification

A special kind of trigger that sends information about database events to a service broker.

event provider

A component that collects event data from one or more event sources and submits the events to the event tables in the application database.

event schema

An SQL-annotated XML Schema definition language (XSD) schema that maps event data to an event schema defined in the application definition file. Used by the EventLoader class.

event source

The point of origin of an event.

event table

A table in the application database that stores event data. It is automatically generated based on information in the application definition file each time NSControl Create or NSControl Update is run. Each row in the table is an event instance.

event-driven subscription (Notification Services)

A subscription in which notifications are generated as soon as event data arrives that matches the subscription.

exclusive lock

A lock that prevents any other transaction from acquiring a lock on a resource until the original lock on the resource is released at the end of the transaction. An exclusive lock is always applied during an update operation (INSERT, UPDATE, or DELETE).


In Integration Services, a package, Foreach Loop, For Loop, Sequence, or task.

execution tree

The path of data in the data flow of a SQL Server Integration Services package from sources through transformations to destinations. The scheduler of the data flow engine uses the trees to build the execution plan of the data flow.

explicit transaction

A group of SQL statements enclosed within transaction delimiters that define both the start and end of the transaction.


1. In SQL, a combination of symbols and operators that evaluate to a single data value. Simple expressions can be a constant, variable, column, or scalar function. Complex expressions are one or more simple expressions connected by operators. 2. In Integration Services, a combination of literals, constants, functions, and operators that evaluate to a single data value.

extended stored procedure

A function in a dynamic link library (DLL) that is coded using the SQL Server Extended Stored Procedure API. The function can then be invoked from Transact-SQL using the same statements that are used to execute Transact-SQL stored procedures. Extended stored procedures can be built to perform functionality not possible with Transact-SQL stored procedures.

Extensible Stylesheet Language (XSL)

An XML vocabulary that is used to transform XML data to another form, such as HTML, by means of a style sheet that defines presentation rules.

Extensible Stylesheet Language Transformations (XSLT)

Evolved from the early Extensible Stylesheet Language (XSL) standard. XSL specifies a language definition for XML data presentation and data transformations. Data presentation means displaying data in some format and/or medium, and concerns style. Data transformation refers to parsing an input XML document into a tree of nodes, and then converting the source tree into a result tree. Transformation concerns data exchange.


The unit of space allocated to a SQL Server object, such as a table or index, whenever the object needs more space.

external delivery system

A system, such as Microsoft Exchange Server, that delivers formatted notifications to destination devices.


A row in a fact table in a data warehouse. A fact contains values that define a data event such as a sales transaction.

fact relationship

A relationship between a dimension and a measure group in which the key attribute of a dimension is bound to a column in the fact table.

fact table

A central table in a data warehouse schema that contains numerical measures and keys relating facts to dimension tables. Fact tables contain data that describes specific events within a business, such as bank transactions or product sales.


In a database mirroring session, the process in which ownership of the principal role is switched from the principal server to the mirror server.

federated database servers

A set of linked servers that shares the processing load of data by hosting partitions of a distributed partitioned view.


An operation that retrieves a row or block of rows from a cursor. Transact-SQL batches, stored procedures, and triggers use the FETCH statement to fetch from Transact-SQL cursors. Applications use API fetch functions.


1. An area in a window or record that stores a single data value. Some databases, such as Access databases, use field as a synonym for column. 2. In Report Builder, a field is an attribute of the entity that is a named unit of data that can be added to a report layout template.

field length

In bulk copy, the maximum number of characters needed to represent a data item in a bulk copy character format data file.

field terminator

In bulk copy, one or more characters marking the end of a field or row, separating one field or row in the data file from the next.


In SQL Server databases, a basic unit of storage for a database. One database can be stored in several files. SQL Server uses three types of files: data files (which store data), log files (which store transaction logs), and backup files (which store backups of a database).

file backup

A backup of all the data in one or more files or filegroups.

file DSN

Stores connection information for a database in a file that is saved on your computer. The file is a text file with the extension .dsn. The connection information consists of parameters and corresponding values that the ODBC Driver Manager uses to establish a connection.

file restore

An operation that restores one or more files of a database.

file storage type

Defines the storage format used in the data file that transfers data from a bulk copy out operation to a bulk copy in operation. In native mode files, all data is stored using the same internal structures that SQL Server uses to store the data in a database. In character mode files, all data is converted to character strings.

file system watcher event provider (Notification Services)

An event provider supplied by Notification Services that monitors a directory for the arrival of XML event files, extracts XML event data from these files, and submits these events to the event table in the application database. The file system watcher uses the event loader class to submit events.


In SQL Server, a named collection of one or more data files that forms a single unit of data allocation or for administration of a database.

fill factor

An attribute of an index that defines how full the SQL Server Database Engine should make each page of the index. The fill factor accommodates the future growth of data in a table and reduces the potential for page splits. The FILLFACTOR option can be a value from 1 up to 100. This value specifies the percentage of space on each leaf-level page to be filled with data.


1. A set of criteria that controls the set of records returned as a result set. Filters can also define the sequence in which rows are returned. 2. In Full-Text Search, given a specified file extension, filters extract text from a file stored in a varbinary(max) or image column.


The ability to restrict data based upon criteria set in the WHERE clause of an SQL statement. For replication, filtering occurs on table articles defined in a publication. The result is partitions of data that can be published to Subscribers.

firehose cursor

See Other Term: default result set


See Other Term: foreign key

flattened interface

An interface created to combine members of multiple interfaces.

flattened rowset

A multidimensional data set presented as a two-dimensional rowset in which unique combinations of elements of multiple dimensions are combined on an axis. For more information, see the OLE DB documentation.

forced service

A failover that is initiated by a database administrator, when the principal server is unavailable, to make a mirrored database available by forcing service to the mirror server (with possible data loss). The mirror server takes over the role of principal server and brings its copy of the database online as the principal database.

foreign key

The column or combination of columns whose values match the primary key (PK) or unique key in the same or another table. Also referred to as the referencing key.

foreign table

A table that contains a foreign key.

forward-only cursor

A cursor that cannot be scrolled; rows can be read only in sequence from the first row to the last row.


A difference between the physical and logical ordering of index data that can occur when data modifications are made. You can reduce fragmentation and improve read-ahead performance by dropping and re-creating a clustered index.

full outer join

A type of outer join in which all rows in all joined tables are included, whether they are matched or not.

full recovery model

A database recovery mode that fully logs all transactions and retains all the log records until after they are backed up. The database can be recovered to the point of failure if the tail of the log is backed up after the failure. All forms of recovery are supported.

full-text catalog

Stores all of the full-text indexes for tables within a database.

full-text index

The portion of a full-text catalog that stores all of the full-text words and their locations for a given table.

full-text query

As a SELECT statement, a query that searches for words, phrases, or multiple forms of a word or phrase in the character-based columns (of char, varchar, text, ntext, nchar, or nvarchar data types). The SELECT statement returns those rows meeting the search criteria.

full-text service

The SQL Server component that performs the full-text querying.


A piece of code that operates as a single logical unit. A function is called by name, accepts optional input parameters, and returns a status and optional output parameters. Many programming languages support functions, including C, Visual Basic, and Transact-SQL. Transact-SQL supplies built-in functions, which cannot be modified, and supports user-defined functions, which can be created and modified by users.

fuzzy grouping

In Integration Services, a data cleaning methodology that examines values in a dataset and identifies groups of related data rows and the one data row that is the canonical representation of the group.

fuzzy matching

In Integration Services, a lookup methodology that uses an approximate matching algorithm to locate similar data values in a reference table.

generator (Notification Services)

The component of Notification Services that matches events to subscriptions and produces notifications.

global default

A default that is defined for a specific database and is shared by columns of different tables.

global rule

A rule that is defined for a specific database and is shared by columns of different tables.

global subscription

See Other Term: server subscription


The degree of specificity of information that is contained in a data element. A fact table that has fine granularity contains many discrete facts, such as individual sales transactions. A table that has coarse granularity stores facts that are summaries of individual elements, such as sales totals per day.

granularity attribute

The attribute of a cube dimension that links a dimension to the facts in a measure group in the measure's dimension. If the granularity attribute and the key attribute are different attributes, then non-key attributes must be linked, directly or indirectly, to the granularity attribute. Within a cube, the granularity attribute defines a dimension's granularity.


A special user account that is present in all SQL Server databases and cannot be removed from any database. If a connection is made using a login that has not been assigned a user account in a database and the connection references objects in that database, it has only the permissions assigned to the guest account in that database.


A table without a clustered index.

heterogeneous data

Data stored in multiple formats. Examples include data stored in a SQL Server database, a text file, and an Excel spreadsheet.


A logical tree structure that organizes the members of a dimension such that each member has one parent member and zero or more child members.


See Other Term: hybrid OLAP

homogeneous data

Data that comes from multiple data sources that are all managed by the same software. A SQL Server distributed query is homogeneous if all the data comes from SQL Server instances.


In data communications, one segment of the path between routers on a geographically dispersed network. The distance between each of those routers is a communications hop.

horizontal partitioning

To segment a single table into multiple tables based on selected rows. Each of the multiple tables has the same columns but fewer rows.

hosted event provider (Notification Services)

An event provider managed by the Notification Services event provider host that gathers event data from one or more event sources and submits the events to an event table in the application database.

hot standby server

A standby server that can support rapid failover without a loss of data from committed transactions. Database mirroring can be used to maintain a hot standby server, depending on the configuration and state of the mirroring session. When the session is synchronized, the mirror server provides a hot standby server.

hybrid OLAP

A storage mode that uses a combination of multidimensional data structures and relational database tables to store multidimensional data. Analysis Services stores aggregations for a HOLAP partition in a multidimensional structure and stores facts in a relational database.

Hypertext Markup Language (HTML)

A system of marking up, or tagging, a document so that it can be published on the World Wide Web. Documents prepared in HTML include reference graphics and formatting tags. You use a Web browser (such as Microsoft Internet Explorer) to view these documents.


See Other Term: index allocation map


The name of an object in a database. An identifier can be from 1 through 128 characters.

identifying field

A field or group of fields that identify an entity as a unique object.

identity column

A column in a table that has been assigned the identity property. The identity property generates unique numbers.

identity property

A property that generates values that uniquely identify each row in a table. When adding rows to a table that has an identity column, SQL Server automatically generates the next identity value based on the last used identity value and the increment value that was specified during column creation.

idle time

A SQL Server Agent condition that defines how much CPU usage by the SQL Server Database Engine constitutes an idle state. SQL Server Agent jobs can then be created to run whenever the Database Engine CPU usage falls below the level that is defined in the idle time definition. This minimizes the effect the SQL Server Agent jobs might have on other tasks that are accessing the database.

immediate updating

An option available with snapshot replication and transactional replication that allows data modifications to be made to replicated data at the Subscriber. The data modifications are then immediately propagated to the Publisher using two-phase commit protocol (2PC).

immediate updating subscriptions

A subscription to a transactional publication for which the user is able to make data modifications at the Subscriber. The data modifications are then immediately propagated to the Publisher using the two-phase commit protocol (2PC).

implicit cursor conversion

The return of a different type of cursor than the user had declared. When a cursor is declared as a particular cursor type but SQL Server is unable to implement the declared type, SQL Server returns a cursor of a different type. This process is known as implicit cursor conversion, sometimes referred to as cursor degradation.

implicit transaction

A connection option in which each SQL statement executed by the connection is considered a separate transaction.

implied permission

Permission to perform an activity specific to a role. Implied permissions cannot be granted, revoked, or denied.

incremental update

The set of operations that either adds new members to an existing cube or dimension, or adds new data to a partition. An incremental update is one of three processing options for a cube or partition, and one of two processing options for a dimension.

independent event provider (Notification Services)

An event provider that is running outside the process environment of Notification Services, and which gathers event data from one or more event sources and submits the events to an event table in the application database.


In a relational database, a database object that provides fast access to data in the rows of a table, based on key values. Indexes can also enforce uniqueness on the rows in a table. SQL Server supports clustered and nonclustered indexes. The primary key of a table is automatically indexed. In full-text search, a full-text index stores information about significant words and their location within a given column.

index allocation map

A page that maps the extents in a 4-GB part of a database file that is used by an allocation unit.

index ORing

An execution strategy that consists of looking up rows of a single table using several indexes, followed by producing the result (by combining the partial results). For example, WHERE R.a = 6 OR R.b = 7 with indexes on columns R.a and R.b.

index page

A database page containing index rows.

indexed view

A view that has a unique clustered index applied on it. Indexed views can improve the performance of some types of queries.

information model

An object-oriented schema that defines metadata constructs used to specify the structure and behavior of an application, process, component, or software artifact.

initial snapshot

Files that include schema and data, constraints, extended properties, indexes, triggers, and system tables that are necessary for replication. By default, the initial snapshot is transferred to Subscribers when implementing replication.

initial synchronization

The first synchronization for a subscription, during which system tables and other objects that are required by replication, and the schema and data for each article, are copied to the Subscriber.

initial tape

In a media set using tape backup devices, the first tape in a media family.

inner join

An operation that retrieves rows from multiple source tables by comparing the values from columns shared between the source tables. An inner join excludes rows from a source table that have no matching rows in the other source tables.

input member

A member whose value is loaded directly from the data source instead of being calculated from other data.

input set

The set of data provided to a Multidimensional Expressions (MDX) value expression upon which the expression operates.

input source

Any table, view, or schema diagram used as an information source for a query.

insensitive cursor

A cursor that does not reflect data modification made to the underlying data by other users while the cursor is open.

Insert Into query

A query that copies specific columns and rows from one table to another or to the same table.

Insert Values query

A query (SQL statement) that creates a new row and inserts values into specified columns.


A copy of SQL Server that is running on a computer.


A data type category that includes the bigint, int, smallint, and tinyint data types.

integrity constraint

A property defined on a table that prevents data modifications that would create invalid data.

intent lock

A lock that is placed on one level of a resource hierarchy to protect shared or exclusive locks on lower-level resources. For example, before a SQL Server Database Engine task applies shared or exclusive row locks within a table, it places an intent lock on the table. If another task tries to apply a shared or exclusive lock at the table level, it is blocked by the table-level intent lock held by the first task. The second task does not have to check for individual page or row locks before locking the table; it only has to check for an intent lock on the table.

interactive structured query language

An interactive command prompt utility provided with SQL Server that lets users run Transact-SQL statements or batches from a server or workstation and view the results that are returned.


A defined set of properties, methods, and collections that form a logical grouping of behaviors and data. Classes are defined by the interfaces that they implement. An interface may be implemented by many different classes.

interface implication

If an interface implies another interface, then any class that implements the first interface must also implement the second interface. Interface implication is used in an information model to get some of the effects of multiple inheritance.

internal identifier

A more compact form of an object identifier in a repository. An internal identifier is guaranteed to be unique only within a single repository.

Internet Protocol security

Rules that computers follow to provide private and secure communication over Internet Protocol (IP) networks, through the use of cryptographic security services.


A publication setting that enables replication to Internet Subscribers.

interprocess communication

A mechanism through which operating system processes and threads exchange data and messages. IPCs include local mechanisms such as Windows shared memory, or network mechanisms such as Windows Sockets.


See Other Term: interprocess communication


See Other Term: Internet Protocol security

isolation level

The property of a transaction that controls the degree to which data is isolated for use by one process, and is guarded against interference from other processes. Setting the isolation level defines the default locking behavior for all SELECT statements in your SQL Server session.


See Other Term: interactive structured query language


A specified series of operations, called steps, performed sequentially by SQL Server Agent.


As a verb, to combine the contents of two or more tables and produce a result set that incorporates rows and columns from each table. Tables are typically joined using data that they have in common. As a noun, the process or result of joining tables, as in the term "inner join" to indicate a particular method of joining tables.

join column

A column referenced in a join condition.

join condition

A comparison clause that specifies how tables are related by their join columns.

join filter

A filter used in merge replication that extends the row filter of one table to a related table.

join operator

A comparison operator in a join condition that determines how the two sides of the condition are evaluated and which rows are returned.

join path

A series of joins indicating how two tables are related. For example, Sales.SalesRepIDSalesReps.ID, SalesReps.BranchIDBranches.ID.

junction table

A table that establishes a relationship between other tables. The junction table contains foreign keys referencing the tables that form the relationship. For example, an OrderParts junction table can show what parts shipped with each order by having foreign keys to an Orders table and a Parts table.


1. In SQL Server, a subset of the storage engine that is referenced in some error messages. 2. In Windows, the core of the operating system that performs basic operations.


A column or group of columns that uniquely identifies a row (primary key), defines the relationship between two tables (foreign key), or is used to build an index.

key attribute

The attribute of a dimension that links the non-key attributes in the dimension to related measures.

key column

1. In an Analysis Services dimension, an attribute property that uniquely identifies the attribute members. 2. In an Analysis Services mining model, a data mining column that uniquely identifies each case in a case table.

Key Performance Indicator

A quantifiable measurement for gauging business success. A KPI is frequently evaluated over time.

key range lock

A lock that is used to lock ranges between records in a table to prevent phantom additions to, or deletions from, a set of records. Ensures serializable transactions.

keyset-driven cursor

A cursor that shows the effects of updates made to its member rows by other users while the cursor is open, but does not show the effects of inserts or deletes.


A reserved word in SQL Server that performs a specific function, such as to define, manipulate, or access database objects.


See Other Term: Key Performance Indicator


The amount of time that elapses when a data change is completed at one server and when that change appears at another (for example, the time between when a change is made at a Publisher and when it appears at the Subscriber).


In a tree structure, an element that has no subordinate elements. For example, in Analysis Services, a leaf is a dimension member that has no descendants.

leaf level

The bottom level of a clustered or nonclustered index. In a clustered index, the leaf level contains the actual data pages of the table. In a nonclustered index, the leaf level either points to data pages or points to the clustered index (if one exists), rather than containing the data itself. In Analysis Services, the bottom level of a hierarchy.

leaf member

A dimension member without descendants.

left outer join

A type of outer join in which all rows from the left-most table in the JOIN clause are included. When rows in the left table are not matched by rows in the right table, all result set columns that come from the right table are assigned a value of NULL.


The name of a set of members in a dimension hierarchy such that all members of the set are at the same distance from the root of the hierarchy. For example, a time hierarchy may contain the levels Year, Month, and Day.

level naming template

A template used to construct level names in a parent-child hierarchy.


In Analysis Services, a folder that contains shared objects, such as shared dimensions, that can be used by multiple objects within a database.

linguistic casing

Functionality provided by the Win32 API for Unicode simple case mapping of Turkic and other locales.

linked dimension

A dimension based on a dimension defined in another Analysis Services database.

linked measure

A measure based on a measure defined in another Analysis Services database.

linked report

A report that references an existing report definition using a different set of parameter values or properties. A linked report can be managed separately from the original report, with unique subsription, security, and history settings.

linked server

A definition of an OLE DB data source used by SQL Server distributed queries. The linked server definition specifies the OLE DB provider required to access the data, and includes enough addressing information for the OLE DB provider to connect to the data. Any rowsets exposed by the OLE DB data source can then be referenced as tables, called linked tables, in SQL Server distributed queries.

linked table

An OLE DB rowset exposed by an OLE DB data source that has been defined as a linked server for use in SQL Server distributed queries. The rowsets exposed by the linked server can be referenced as tables in distributed queries.

linking table

A table that has associations with two other tables, and is used indirectly as an association between those two tables.

list data region

A report item on a report layout that displays data in a list format. A list data region can also display other data regions, text boxes, and graphical elements in a free-form layout.

local cube

A cube created and stored with the extension .cub on a local computer using PivotTable Service.

local Distributor

A server that is configured as both a Publisher and a Distributor for SQL Server Replication.

local group

A group in Windows NT 4.0 or Windows 2000 containing user accounts and global groups from the domain group in which they are created and any trusted domain. Local groups cannot contain other local groups.

local login identification

The identification (ID) a user must use to log in to a local server. A login ID can have up to 128 characters. The characters can be alphanumeric; however, the first character must be a letter (for example, CHRIS or TELLER8).

local partitioned view

A view that joins horizontally partitioned data from a set of member tables that exist on one server. The data appears as if it is in one table.

local server

1. In SQL Server connections, an instance of SQL Server running on the same computer as the application. 2. In a Transact-SQL statement, when resolving references to database objects, the instance of SQL Server executing the statement. 3. In SQL Server distributed queries, the instance of SQL Server executing the distributed query. The local server then accesses any linked servers referenced in the query.

local subscription

See Other Term: client subscription

local variable

A user-defined variable that has an assigned value. A local variable is defined with a DECLARE statement, assigned an initial value with a SELECT or SET statement, and used within the statement batch or module in which it was declared.


The Windows operating system attribute that defines certain behaviors related to language. The locale defines the code page, or bit patterns, used to store character data, and the order in which characters are sorted. It also defines language-specific items such as the format used for dates and time and the character used to separate decimals in numbers. Each locale is identified by a unique number, referred to as a locale identifier or LCID. SQL Server collations are similar to locales in that the collations define language-specific types of behaviors for instances of SQL Server.

locale identifier (LCID)

A number that identifies a Windows-based locale.


A restriction on access to a resource in a multiuser environment. SQL Server locks users out of a specific row, column, or file automatically to maintain security or prevent concurrent data modification problems.

lock escalation

The process of converting many fine-grain locks into fewer coarse-grain locks, thereby reducing system overhead.

log backup

A backup of transaction logs that includes all log records that were not backed up in previous log backups. Log backups are required under the full and bulk-logged recovery models. Log backups are unavailable under the simple recovery model.

log chain

A continuous sequence of transaction logs for a database. A new log chain starts with the first backup that is taken after the database is created, or when the database is switched from the simple to the full or bulk-logged recovery model. A log chain forks after a restore operation is followed by a recovery. This creates a new recovery branch.

log file

A file or set of files that contain records of the modifications made in a database.

log provider

In Integration Services, the means for writing log entries to text files, SQL Server, SQL Server Profiler, Windows Event Log, and XML files.

log sequence number

A number that uniquely identifies every record in the Microsoft SQL Server transaction log, in the order in which the underlying transaction occurred.

log shipping

The process of copying, at set intervals, a log backup from a read/write database (the primary database) on a primary server to one or more copies (the secondary databases) that reside on remote servers. The secondary servers are warm standbys for the primary server.

log shipping configuration

A configuration of servers that includes one primary server, one or more secondary servers (each with a secondary database), and a monitor server.

log shipping job

A job that performs one of the following log shipping operations: backing up the transaction log of the primary database at the primary server (the backup job), copying the transaction log file to a secondary server (the copy job), or restoring the log backup to the secondary database on a secondary server (the restore job). The backup job resides on the primary server. The copy and restore jobs reside on each of the secondary servers.

logical backup device

An optional user-defined name that points to a specific physical backup device, such as a disk file or tape drive.

logical name

A name used by SQL Server to identify a file. A logical name for a file must correspond to the rules for identifiers and can have as many as 30 characters (for example, ACCOUNTING or LIBRARY).

logical operators

The operators AND, OR, and NOT. Used to connect search conditions in WHERE clauses.

logical records

A merge replication feature allows you to define a relationship between related rows in different tables so that the rows are processed as a unit.

login security mode

A security mode that determines the manner in which an instance of SQL Server validates a login request. There are three types of login security: Windows authentication, SQL Server authentication, and Mixed Mode authentication. Mixed Mode combines the Windows and SQL Server authentication modes.

lookup table

In Integration Services, a reference table for comparing, matching, or extracting data.


See Other Term: log sequence number

machine DSN

Stores connection information for a database in the system registry. The connection information consists of parameters and corresponding values that the ODBC Driver Manager uses to establish a connection.

Make Table query

A query, or SQL statement, that creates a new table, and then creates rows in the table by copying rows from an existing table.

manual failover

A failover that is initiated by a database administrator that causes the mirror server to take over the role of principal server and bring its copy of the database online as the principal database.

many-to-many relationship

A relationship between two tables in which rows in each table have multiple matching rows in the related table. Many-to-many relationships are maintained by using a third table, referred to as a junction table, and adding the primary key columns from each of the other two tables to this table.

many-to-one relationship

A relationship between two tables in which one row in one table can relate to many rows in another table.

master database

The system database that records all the system-level information for an instance of SQL Server. This includes instance-wide metadata such as login accounts, endpoints, linked servers, and system configuration settings. Also, master is the database that records the existence of all other databases and the location of those database files and records the initialization information for SQL Server.

master server

A server that distributes jobs and receives events from multiple servers.

matrix data region

A report item on a report layout that displays data in a variable columnar format.


See Other Term: Multidimensional Expressions


In a cube, a set of values that are usually numeric and are based on a column in the fact table of the cube. Measures are the central values that are aggregated and analyzed.

measure expression

The value of a measure, based on a column in a fact table as modified by a Multidimensional Expressions (MDX) expression.

measure group

A collection of related measures in an Analysis Services cube. The measures are generally from the same fact table.

measure group type

Specifies the type of information the measure group contains, which may enable specific treatment by the server and client applications.

measures dimension

The dimension that contains all the measures in a cube.

measures group

The dimension that contains all of the measures in a cube.

media family

Data written by a backup operation to a backup device that is being used by a media set. In a media set that has one device, only one media family exists. In a striped media set, multiple media families exist. If the striped media set is unmirrored, each device corresponds to a family. If the striped media set is mirrored, the mirrored media set contains from two to four identical copies of each media family, which are called mirrors.

media header

A label that provides information about the backup media.

media name

The descriptive name for the whole backup media set.

media set

An ordered collection of backup media written to by one or more backup operations using a constant number of backup devices.


An item in a dimension representing one or more occurrences of data. A member can be either unique or nonunique. For example, 1997 and 1998 represent unique members in the year level of a time dimension, whereas January represents nonunique members in the month level because there can be more than one January in the time dimension if it contains data for more than one year.

member delegation

A modeling concept that describes how interface members are mapped from one interface to another.


A type of column that contains long strings, typically more than 255 characters. A memo is the equivalent in Microsoft Access to a SQL Server text data type.


The operation that combines two partitions into a single partition.

merge replication

A type of replication that typically starts with a snapshot of the publication database objects and data. Subsequent data changes and schema modifications made at the Publisher and Subscribers are tracked with triggers. The Subscriber synchronizes with the Publisher when connected to the network and exchanges all rows that have changed between the Publisher and Subscriber since the last time synchronization occurred.

message number

A number that identifies a SQL Server error message.

Message Queuing

An asynchronous messaging framework distributed with Windows Server.

Messaging Application Programming Interface (MAPI)

An e-mail API.


A function that performs an action by using a COM object, as in SQL-DMO, OLE DB, and ActiveX Data Objects (ADO).

mining model

An object that contains the definition of a data mining process and the results of the training activity. For example, a data mining model may specify the input, output, algorithm, and other properties of the process and hold the information gathered during the training activity, such as a decision tree.

mining model training

The process a data mining model uses to estimate model parameters by evaluating a set of known and predictable data. Also, the act of causing a mining model to evaluate training data.

mirror database

In a database mirroring session, the copy of the database that is typically fully synchronized with the principal database.

mirror server

In a database mirroring configuration, the server instance on which the mirror database resides.

mirrored media set

A media set that contains two to four identical copies (mirrors) of each media family. Restore operations require only one mirror per family. This allows for a damaged media volume to be replaced by the corresponding volume from a mirror.


The process that helps protect against the loss of data caused by disk failure by maintaining a fully redundant copy of data on a separate disk. Mirroring can be implemented at several levels: in SQL Server, in the operating system, and in the disk controller hardware.

Mixed Mode

See Other Term: login security mode

model database

A database installed with SQL Server that provides the template for new user databases. SQL Server creates a new database by copying in the contents of the model database, and then expanding it to the size requested.

model dependency

A relationship between two or more models in which one model is dependent on the information of another model.


A group of objects in a project. You can move objects between modules in a project, thus organizing those objects for a dispersed development environment.


An arithmetic operator that provides the integer remainder after a division involving two integers.

monitor server

In a log shipping configuration, a server instance on which every log shipping job in the configuration records its history and status. A single-monitor server can monitor multiple log shipping configurations.


See Other Term: Message Queuing


See Other Term: master server

multibase differential

A differential backup that includes files that were last backed up in distinct base backups.

multicast delivery

A method for delivering notifications that formats a notification once, and then sends the resulting message to multiple Subscribers.

Multidimensional Expressions

A syntax used for defining multidimensional objects, and for querying and manipulating multidimensional data.

multidimensional OLAP

A storage mode that uses a proprietary multidimensional structure to store a partition's facts and aggregations or a dimension. The data of a partition is completely contained within the multidimensional structure.

multidimensional structure

A database paradigm that treats data as cubes that contain dimensions and measures in cells. Each cell is addressed by a set of coordinates that specify a position in the cube's structure.

multiple inheritance

A modeling term that describes how an interface receives the characteristics of more than one parent interface.

multiserver administration

The process of automating administration across multiple instances of SQL Server.

multithreaded server application

An application that creates multiple threads within a single process to service multiple user requests at the same time.


The ability of a computer to support many users operating at the same time, while providing the computer system's full range of capabilities to each user.

name column

The property of an attribute that specifies the names of the attribute members that appear to users.

named instance

An installation of SQL Server that is given a name to differentiate it from other named instances and from the default instance on the same computer. A named instance is identified by the computer name and instance name.

named pipe

An interprocess communication (IPC) mechanism that SQL Server uses to provide communication between clients and servers. Named pipes permit access to shared network resources.

named set

A set of dimension members or a set expression that is created for reuse, for example, in Multidimensional Expressions (MDX) queries.

naming relationship

A naming convention that identifies the destination objects of that relationship by name.

native format

Bulk copy data files in which the data is stored using the same internal data structures SQL Server uses to store data in SQL Server databases. Bulk copy can quickly process native mode files because it does not have to convert data when transferring it between SQL Server and the bulk copy data file.

natural hierarchy

A user-defined hierarchy in which a one-to-many relationship is defined between levels.

nested query

A SELECT statement that contains one or more subqueries, or another term for subquery.

nested table

A data mining model configuration in which a column of a table contains a table.


A SQL Server communications component that isolates the SQL Server client software and Database Engine from the network APIs. The SQL Server client software and Database Engine send generic network requests to a Net-Library, which translates the request to the specific network commands of the protocol chosen by the user.


When used with merge replication system tables, a name for another Subscriber that is known to already have a specified generation of updated data. Used to avoid sending an update to a Subscriber that has already received those changes.

niladic functions

Functions that do not have any input parameters. Most niladic SQL Server functions return system information.

noise word

Words that do not participate in a full-text query search, such as "a", "and", and "the".

nonclustered index

An index in which the logical order of the index key values is different than the physical order of the corresponding rows in a table. The index contains row locators that point to the storage location of the table data.

non-empty behavior

A property of a calculated member, which is a base member; if the base member is null, Analysis Services will not resolve the calculated member.


In a tree structure, an element that has one or more subordinate elements. In Analysis Services, a dimension member that has one or more descendants. In SQL Server indexes, an intermediate index node that points to other intermediate nodes or leaf nodes.

nonleaf member

A member with one or more descendants.

nonrepeatable read

An inconsistency that occurs when a transaction reads the same row more than once, and a separate transaction modifies that row between reads. Because the row was modified, each read produces different values.

non-uniform memory access

A multiprocessor architecture that divides a system into nodes. Each node might include one or more processors, some memory, and a bus. A node's memory is "local" to its processors, and the processors can access the memory relatively fast. Processors in one node can also access memory in different ("distant") nodes, but access time is slower. "Non-uniform memory access" refers to this difference between the speed at which processors can access local memory and the speed at which they can access distant memory. Most NUMA architectures are also ccNUMA (cache-coherent NUMA) architectures, because they provide cache coherency across the nodes.

normalization rules

A set of database design rules that minimizes data redundancy and results in a database in which the Database Engine and application software can easily enforce integrity.

NS$instance_name (Notification Services)

The name of the Windows service that runs an instance of Notification Services. Note that instance_name is a placeholder for the actual instance name, such as NS$ThisInstance.


An entry that has no explicitly assigned value. NULL is not equivalent to zero or blank. A value of NULL is not considered to be greater than, less than, or equivalent to any other value, including another value of NULL.


The attribute of a column, parameter, or variable that specifies whether it allows null data values.


See Other Term: non-uniform memory access

numeric expression

Any expression that evaluates to a number. The expression can be any combination of variables, constants, functions, and operators.

object dependencies

References to other objects when the behavior of the first object can be affected by changes in the object it references. For example, if a stored procedure references a table, changes to the table can affect the behavior of the stored procedure.

object identifier

1. A unique name given to an object. 2. In Metadata Services, a unique identifier constructed from a globally unique identifier (GUID) and an internal identifier. All objects must have an object identifier.

object variable

A variable that contains a reference to an object.


See Other Term: Open Database Connectivity

ODBC data source

The location of a set of data that can be accessed using an ODBC driver. Also, a stored definition that contains all of the connection information an ODBC application requires to connect to the data source.

ODBC driver

A dynamic-link library (DLL) that an ODBC-enabled application, such as Excel, can use to access an ODBC data source. Each ODBC driver is specific to a database management system (DBMS), such as SQL Server or Access.

offline restore

A restore operation that occurs when the database is offline.


See Other Term: online analytical processing (OLAP)

OLE Automation controller

A programming environment (for example, Visual Basic) that can drive Automation objects.

OLE Automation objects

A Component Object Model (COM) object that provides Automation-compatible interfaces.

OLE Automation server

An application that exposes programmable automation objects to other applications, which are referred to as automation clients. Exposing programmable objects enables clients to automate certain functions by directly accessing those objects and using the services they make available. For example, a word processor might expose its spell-checking functionality so that other programs can use it.


A COM-based API for accessing data. OLE DB supports accessing data stored in any format (databases, spreadsheets, text files, and so on) for which an OLE DB provider is available.

OLE DB consumer

Any software that calls and uses the OLE DB API.


Formerly, the separate specification that addressed OLAP extensions to OLE DB. Beginning with OLE DB 2.0, OLAP extensions are incorporated into the OLE DB specification.

OLE DB provider

A software component that exposes OLE DB interfaces. Each OLE DB provider exposes data from a particular type of data source, such as SQL Server databases, Access databases, or Excel spreadsheets.


See Other Term: online transaction processing

one-to-many relationship

In relational databases, a relationship between two tables in which a single row in the first table can be related to one or more rows in the second table, but a row in the second table can be related only to one row in the first table.

one-to-one relationship

In relational database, a relationship between two tables in which a single row in the first table can be related only to one row in the second table, and a row in the second table can be related only to one row in the first table.

online analytical processing (OLAP)

A technology that uses multidimensional structures to provide rapid access to data for analysis. The source data for OLAP is commonly stored in data warehouses in a relational database.

online mode

A direct connection to an Analysis Services database, through which changes can be made directly to that database rather than through a project.

online restore

A restore in which one or more secondary filegroups, files that belong to secondary filegroups, or pages are restored; while, minimally, the primary filegroup remains online. During an online file restore, the filegroup to which a file is being restored is taken offline.

online transaction processing

A data processing system designed to record all of the business transactions of an organization as they occur. An OLTP system is characterized by many concurrent users actively adding and modifying data.

Open Data Services

The layer of the SQL Server Database Engine that transfers client requests to the appropriate functions in the Database Engine. Open Data Services exposes the extended stored procedure API used to write DLL functions that can be called from Transact-SQL statements.

Open Database Connectivity

A data access API that supports access to any data source for which an ODBC driver is available. ODBC is aligned with the American National Standards Institute (ANSI) and International Organization for Standardization (ISO) standards for a database call-level interface (CLI).

Open Information Model

An information model published by the Metadata Coalition (MDC) and widely supported by software vendors. The OIM is a formal description of metadata constructs organized by subject area.

optimize synchronization

An option in merge replication that allows you to minimize network traffic when determining whether recent changes have caused a row to move into or out of a partition that is published to a Subscriber.

ordered set

A set of members returned in a specific order. The ORDER function in a Multidimensional Expressions (MDX) query returns an ordered set.

origin object

An object in a repository that is the origin in a directional relationship.

outer join

A join that includes all the rows from the joined tables that have met the search conditions, even rows from one table for which there is no matching row in the other join table. For result set rows returned when a row in one table is not matched by a row from the other table, a value of NULL is supplied for all result set columns that are resolved to the table that had the missing row.


The characteristic of some data mining algorithms that assigns importance to random variations in data by viewing them as important patterns.


A bundle of data that is organized in a group for transmission. A packet typically contains three elements: control information, data to be transferred, and error detection and correction bits.


In a virtual storage system, a fixed-length block of contiguous virtual addresses copied as a unit from memory to disk and back during paging operations. SQL Server allocates database space in pages. In SQL Server, a page is 8 KB in size.

page footer

A set of static text, images, lines, rectangles, borders, background color, and background images that repeats on the bottom of each page of a report.

page header

A set of static text, images, lines, rectangles, borders, background color, and background images that repeats on the top of each page of a report.

page restore

An operation that restores one or more data pages. Page restore is intended for repairing isolated damaged pages.

page split

The process of moving half the rows or entries in a full data or index page to a new page to make room for a new row or index entry.


In Transact-SQL queries, the act of using parameters or parameter markers instead of constant values. Parameterization helps the SQL Server query optimizer match new Transact-SQL queries with execution plans that have been previously compiled and cached.

parameterized report

A published Reporting Services report that accepts input values through parameters.

parameterized row filter

A row filter that is available with merge replication that lets you restrict the data that is replicated to a Subscriber based on the system function HOST_NAME and/or SUSER_SNAME (or a user-defined function that references one or both of these system functions). Referred to as a dynamic filter in previous versions of SQL Server.


A member in the next higher level in a hierarchy that is directly related to the current member. The parent value is usually a consolidation of the values of all of its children. For example, in a Time dimension containing the levels Quarter, Month, and Day, Qtr1 is the parent of January.

parent member

A member of a parent-child hierarchy that contains the aggregated value of its children.

parent-child hierarchy

A special type of attribute hierarchy in which an attribute in the dimension is set to parent. A parent-child hierarchy is an unbalanced hierarchy of child and parent members. A parent-child hierarchy contains the following levels: child levels that contain the children of parent members (The children of a parent include the attribute members that aggregate to the parent member, including data members.); Intermediate levels that contain parent members; and an optional (All) level that contains the aggregated value of the parent-child hierarchies leaf members, with the member of the (All) level also known as the (All) member. Only one parent-child hierarchy can exist per dimension and must be related to the key attribute.

partial backup

A backup of all the data in the primary filegroup, every read/write filegroup, and any optionally specified read-only files.

partial database restore

A restore of only a part of a database that consists of its primary filegroup and, perhaps, one or more secondary filegroups. Initially, the other filegroups remain offline, but they can be restored later.


1. In replication, a subset of rows from a published table, created with a static row filter or a parameterized row filter. 2. In Analysis Services, one of the storage containers for data and aggregations of a cube. Every cube contains one or more partitions. For a cube with multiple partitions, each partition can be stored separately in a different physical location. Each partition can be based on a different data source. Partitions are not visible to users; the cube appears to be a single object. 3. In the Database Engine, a unit of a partitioned table or index.

partition function

A function that defines how the rows of a partitioned table or index are spread across a set of partitions based on the values of specific columns, which are referred to as partitioning columns

partition scheme

A database object that maps the partitions of a partition function to a set of filegroups.

partitioned snapshot

In merge replication, a snapshot that includes only the data from a single partition. A partitioned snapshot is used to initialize subscriptions to publications that have parameterized filters. Referred to as a dynamic snapshot in previous versions of SQL Server.

partitioned table

A table built on a partition scheme, and whose data is horizontally divided into units which may be spread across more than one filegroup in a database.


The process of replacing a table with multiple smaller tables. Each smaller table has the same format as the original table, but with a subset of the data. Each partitioned table has rows allocated to it based on some characteristic of the data, such as specific key ranges. The rules that define into which table the rows go must be unambiguous. For example, a table is partitioned into two tables. All rows with primary key values lower than a specified value are allocated to one table, and all keys equal to or greater than the value are allocated to the other. Partitioning can improve application processing speeds and reduce the potential for conflicts in multisite update replication. You can improve the usability of partitioned tables by creating a view. The view, created by a union of select operations on all the partitioned tables, presents the data as if it all resided in a single table.

partitioning column

The column of a table or index that a partition function uses to partition a table or index.


In database mirroring, refers to the principal server or the mirror server.

pass order

The order of evaluation (from highest to lowest calculation pass number) and calculation (from lowest to highest calculation pass number) for calculated members, custom members, custom rollup formulas, and calculated cells in a multidimensional cube. Pass order is used to determine formula precedence when calculating values for cells in multidimensional cubes, across all calculation passes.

pass-through query

A query passed uninterpreted to an external server for evaluation. The result set returned by a pass-through query can be used in the FROM clause of a query like an ordinary base table.

pass-through statement

A SELECT statement that is passed directly to the source database without modification or delay. In PivotTable Service, the PASSTHROUGH option is part of the INSERT INTO statement.

password policy

A collection of policy settings that define the password requirements for a Group Policy object (GPO).


In Integration Services, a path connects data flow components into an ordered data flow.

peer-to-peer replication

A type of transactional replication. In contrast to read-only transactional replication and transactional replication with updating subscriptions, the relationships between nodes in a peer-to-peer replication topology are peer relationships rather than hierarchical ones, with each node containing identical schema and data.

persisted computed column

A computed column of a table that is physically stored. The values of a persisted computed column are updated when any column that is part of the computation changes. When the persisted property is applied to a computed column, indexes can be created on the column when the column is deterministic, but not precise.


The saving of an object definition so it will be available after the current session ends.


A focused view of a cube.


By one task, the insertion of a new row or the deletion of an existing row in a range of rows previously read by another task that has not yet committed its transaction. The task with the uncommitted transaction cannot repeat its original read because of the change to the number of rows in the range. If a connection sets its transaction isolation level to serializable, SQL Server uses key-range locking to prevent phantoms.

physical backup device

A tape drive or a disk file that is provided by the operating system to hold one or more backups. See Other Term: logical backup device

physical name

The path where a file or mirrored file is located. The default is the path of the Master.dat file followed by the first eight characters of the file's logical name. For example, if Accounting is the logical name, and the Master.dat file is located in Sql\Data, the default physical name is Sql\Data\Accounti.dat. For a mirrored file, the default is the path of the Master.mir file followed by the first eight characters of the mirror file's logical name. For example, if Maccount is the name of the mirrored file, and the Master.mir file is located in Sql\Data, the default physical name is Sql\Data\Maccount.mir.

physical reads

Requests for database pages that cause SQL Server to transfer the requested pages from disk to the SQL Server buffer pool.

piecemeal restore

A composite restore process in which a database is restored in stages, where each stage corresponds to a restore sequence. The initial, partial restore sequence restores the files in the primary filegroup and perhaps other files to any point in time that is supported by the recovery model, and then brings the database online. Subsequent restore sequences bring remaining files to the point that is consistent with the database and then bring them online.


1. To rotate rows to columns, and columns to rows, in a crosstabular data browser. 2. To choose dimensions from the set of available dimensions in a multidimensional data structure for display in the rows and columns of a crosstabular structure.


See Other Term: primary key

plan forcing

The act of using the USE PLAN query hint to force the SQL Server query optimizer to use a specified query plan for a query.

plan guide

A SQL Server module that attaches query hints to queries in deployed applications, without directly modifying the query.

platform (Notification Services)

The Notification Services engine and the Notification Services SQL Server databases. The platform stores system data and provides functions for notification generation and distribution.

point-in-time recovery

The process of recovering only the transactions within a log backup that were committed before a specific point in time, instead of recovering the whole backup.


In Full-text Search, the process of creating and maintaining a full-text index.


The current location of processing in a cursor. For example, after an application fetches the first 10 rows from a cursor, it is positioned on the tenth row of the cursor. Database APIs also have functions, such as the ODBC SQLSetPos function, that allow an application to move directly to a specific position in a cursor without performing a fetch.

positioned update

An update, insert, or delete operation performed on a row at the current position of the cursor. The actual change is made in the rows of the base tables used to build the current row in the cursor. Transact-SQL batches, stored procedures, and triggers use the WHERE CURRENT OF clause to perform positioned updates. Applications use API functions, such as the ODBC SQLSetPos function, to perform positioned updates.

precedence constraint

In Integration Services, precedence constraints connect executables, containers and tasks in packages, and specify conditions that determine whether executables run.


The maximum total number of decimal digits that can be stored, both to the left and right of the decimal point.

precomputed partitions

In merge replication, a performance optimization that is used by default for filtered publications.


A data mining technique that analyzes existing data and uses the results to predict values of attributes for new records or missing attributes in existing records. For example, existing credit application data can be used to predict the credit risk for a new application.

prefix characters

A set of 1 to 4 bytes that prefix each data field in a native-format bulk-copy data file. The prefix characters record the length of the data value in the field, or contain -1 when the value is NULL.

prefix length

The number of prefix characters preceding each noncharacter field in a bcp native format data file.

prefix search

Full-text query searching for those columns where the specified character-based text, word, or phrase, is the prefix. When using a phrase, each word within the phrase is considered to be a prefix. For example, a prefix search specifying the phrase "sport fish*" matches "sport fishing", "sportsman fishing supplies", and so on.

primary database

In a log shipping configuration, a read/write database whose transaction log is backed up at set intervals for restoring onto one or more secondary databases.

primary dimension table

In a snowflake schema in a data warehouse, a dimension table that is directly related to and usually joined to the fact table. Additional tables that complete the dimension definition are joined to the primary dimension table instead of to the fact table.

primary key

A column or set of columns that uniquely identify all the rows in a table. Primary keys do not allow null values. No two rows can have the same primary key value; therefore, a primary key value always uniquely identifies a single row. More than one key can uniquely identify rows in a table. Each of these keys is called a candidate key. Only one candidate can be chosen as the primary key of a table; all other candidate keys are known as alternate keys. Although tables are not required to have primary keys, it is good practice to define them. In a normalized table, all the data values in each row are fully dependent on the primary key. For example, in a normalized employee table that has EmployeeID as the primary key, all the columns should contain data related to a specific employee. This table does not have the column DepartmentName because the name of the department is dependent on a department ID, not on an employee ID.

primary server

In a log shipping configuration, the server instance on which the primary database resides.

primary table

The "one" side of two related tables in a one-to-many relationship. A primary table should have a primary key, and each record should be unique. An example of a primary table is a table of customer names that are uniquely identified by a CustomerID primary key field.

principal database

In database mirroring, a read/write database whose transaction log is continuously sent to the mirror server. This restores the log to the mirror database.

principal server

In database mirroring, the partner whose database is currently the principal database.

procedure cache

The part of the SQL Server memory pool that is used to store execution plans for Transact-SQL batches, stored procedures, and triggers. When any SQL statement is executed, the relational engine first looks through the procedure cache to verify that an existing execution plan for the same SQL statement exists. Any existing plan is reused, saving the overhead of recompiling the SQL statement. If no existing execution plan exists, SQL Server generates a new execution plan for the query.


1. In a cube, to populate a cube with data and aggregations. 2. In a data mining model, to populate a data mining model with data mining content.


Collects events in a specific event category and sends the data to a SQL Server Profiler queue.

project mode

A connection to an Analysis Services project, through which changes are made offline and then deployed to modify an Analysis Services database.


A named attribute of a control, field, or database object that you set to define one of the object's characteristics, such as size, color, or screen location; or an aspect of its behavior, such as whether it is hidden.


A standard set of formats and procedures that enable computers to exchange information.


1. An OLE DB provider. 2. An in-process dynamic link library (DLL) that provides access to a database.

provider host (Notification Services)

The component of Notification Services that hosts event providers within the Notification Services engine. At the application level, the provider host is optional because event providers can run independently of Notification Services.


To install, to supply, to grant, or to provide. For example: "You must provision the server with a certificate." or "The SQL Server login must be provisioned with CREATE DATABASE permission."

proximity search

Full-text query searching for those occurrences where the specified words are close to one another.


A publication is a collection of one or more articles from one database. The grouping of multiple articles into a publication makes it easier to specify a logically related set of database objects and data that are replicated as a unit.

publication database

A database on the Publisher from which data and database objects are marked for replication and propagated to Subscribers.

publication retention period

In merge replication, the amount of time a subscription can remain unsynchronized. If the retention period is exceeded, the subscription might require reinitialization. Also referred to as the subscription expiration period.

published data

Data at the Publisher that has been replicated.


A database instance that makes data available to other locations through replication. The Publisher can have one or more publications, each defining a logically related set of objects and data to replicate.

publishing server

A server running an instance of Analysis Services that stores the source cube for one or more linked cubes.

publishing table

The table at the Publisher in which data has been marked for replication and is part of a publication.

pull subscription

A subscription created and administered at the Subscriber. The Distribution Agent or Merge Agent for the subscription runs at the Subscriber.

push subscription

A subscription created and administered at the Publisher. The Distribution Agent or Merge Agent for the subscription runs at the Distributor.


A character used to mark the boundaries of a data type. For example, quotation marks are often used as a text qualifier. In SQL Server, the qualifier represents the database name in a three-part naming convention. In XML, a prefix that qualifies an element with its namespace.


A period of time defined in the application definition file that sets the timing for generator firing.

query binding

The binding of an object to a query.

query optimizer

The SQL Server Database Engine component responsible for generating efficient execution plans for SQL statements.

question template

A structure that describes a set of questions that can be asked using a particular relationship or set of relationships.


A SQL Server Profiler queue that provides a temporary holding location for server events to be captured.

queued updating subscriptions

A subscription to a transactional publication for which the user is able to make data modifications at the Subscriber. The data modifications are stored in a queue and then propagated to the Publisher.


In a database mirroring session for which a witness server instance is set, a relationship established only when at least two of the server instances in the session are connected to each other. Quorum is required to make the database available.

ragged hierarchy

See Other Term: unbalanced hierarchy

range partitioning

A way of partitioning a table or index by specifying partitions to hold rows that have ranges of values from one partitioning column.

range query

A query that specifies a range of values as part of the search criteria, such as all rows from 10 through 100.


For full-text and SQL Server Books Online searches, a value indicating how closely rows or topics match the specified search criteria. For Metadata Services and Analysis Services, a value indicating the relative positions of elements such as dimension members, hierarchy levels, or tuples in a set.

raw file

In Integration Services, a native format for fast reading and writing of data to files.


See Other Term: Report Definition Language


A group of related fields (columns) of information treated as a unit. A record is more commonly called a row in a relational database.


The ActiveX Database Objects (ADO) object that is used to contain a result set. It also exhibits cursor behavior depending on the recordset properties set by an application. ADO recordsets are mapped to OLE DB rowsets.


A phase of database startup that brings the database into a transaction-consistent state. Recovery can include rolling forward all the transactions in the log records (the redo phase) and rolling back uncommitted transactions (the undo phase), depending on how the database was shut down.

recovery branch

A range of LSNs that share the same recovery branch GUID. A new recovery branch originates when a database is created or when RESTORE WITH RECOVERY generates a recovery fork. A multiple-branch recovery path that includes ranges of LSNs that cover two or more recovery fork points is possible.

recovery fork point

The point (LSN,GUID) at which a new recovery branch is started every time a RESTORE WITH RECOVERY operation is performed. Each recovery fork determines a parent-child relationship between recovery branches. If a database is recovered to an earlier point in time and the database is used from that point, the recovery fork point starts a new recovery path.

recovery interval

The maximum amount of time that the Database Engine should require to recover a database. The Database Engine makes sure that the active part of the database log is small enough to recover the database in the amount of time specified for the recovery interval.

recovery model

A database property that controls the basic behavior of backup and restore operations for a database. For instance, the recovery model controls how transactions are logged, whether the transaction log requires backing up, and what kinds of restore operations are available.

recovery path

The sequence of data and log backups that have brought a database to a particular point in time, known as a recovery point. A recovery path is a specific set of transformations that have evolved the database over time, yet have maintained the consistency of the database. A recovery path describes a range of log sequence numbers. The range of log sequence numbers in a recovery path can traverse one or more recovery branches from start to end.

recovery point

The point in the log chain at which roll forward stops during a recovery.

recursive hierarchy

A hierarchy of data in which all parent-child relationships are represented in the data.


The phase during recovery that applies (rolls forward) logged changes to a database to bring the data forward in time.

redo queue

In database mirroring, copies of log records from the principal database that have been written to disk on the mirror server and are waiting to be applied to the mirror database.

referenced key

A primary key or unique key referenced by a foreign key.

referenced relationship

An indirect relationship between a dimension and a measure group based on another dimension.

referencing key

See Other Term: foreign key

referential integrity

A state in which all foreign key values in a database are valid. For a foreign key to be valid, it must contain either the value NULL, or an existing key value from the primary or unique key columns referenced by the foreign key.

reflexive relationship

A relationship from a column or combination of columns in a table to other columns in that same table. A reflexive relationship is used to compare rows within the same table. In queries, this is called a self-join.

refresh data

The series of operations that clears data from a cube, loads the cube with new data from the data warehouse, and calculates aggregations. Refresh data is used when a cube's underlying data in the data warehouse changes but the cube's structure and aggregation definitions remain the same. One of three processing options for a cube.

register (Notification Services)

To configure a computer to be a part of a Notification Services instance. NSControl Register creates the NS$instance_name service, configures security for the service, and creates performance counters for the instance.

regular relationship

A direct relationship between a dimension and a measure group based on the key attribute.

relational database

A collection of information organized in tables. Each table models a class of objects of interest to the organization (for example, Customers, Parts, Suppliers). Each column in a table models an attribute of the object (for example, LastName, Price, Color). Each row in a table represents one entity in the class of objects modeled by the table (for example, the customer name John Smith or the part number 1346). Queries can use data from one table to find related data in other tables.

relational database management system (RDBMS)

A system that organizes data into related rows and columns. SQL Server is a relational database management system (RDBMS).

relational OLAP

A storage mode that uses tables in a relational database to store multidimensional structures.


1. A link between tables that references the primary key in one table to a foreign key in another table. The relationship line is represented in a database diagram by a solid line if referential integrity between the tables is enforced, or a dashed line if referential integrity is not enforced for INSERT and UPDATE transactions. The endpoints of a relationship line show a primary key symbol to denote a primary key-to-foreign key relationship, or they show an infinity symbol to denote the foreign key side of a one-to-many relationship. 2. In Metadata Services, a relationship is an association between a pair of objects, where one object is an origin and the other object is a destination. The association repeats for each subsequent pair of objects, so that the destination of one relationship becomes the origin in the next relationship. In this way, all objects in an information model are associated through a chain of relationships that extend from one object to the next throughout the information model.

relationship object

An object representing a pair of objects that assume a role in relation to each other.

relationship type

A definition of a relationship between two interfaces, as defined in an information model. A relationship type is similar to a class in that it describes characteristics to which specific instances must conform.

remote data

Data stored in an OLE DB data source that is separate from the current instance of SQL Server. The data is accessed by establishing a linked server definition or using an ad-hoc connector name.

remote Distributor

A server configured as a Distributor that is separate from the server configured as the Publisher.

remote login identification

The login identification assigned to a user for accessing remote procedures on a remote server.

remote partition

A partition whose data is stored on a server running an instance of Analysis Services, other than the one used to store the metadata of the partition.

remote stored procedure

A stored procedure located on one instance of SQL Server that is executed by a statement on another instance of SQL Server.

remote table

A table stored in an OLE DB data source that is separate from the current instance of SQL Server. The table is accessed by either establishing a linked server definition or using an ad-hoc connector name.

rendered report

A fully processed report that contains both data and layout information, in a format suitable for viewing.

rendering extension

A component in Reporting Services that is used to process the output format of a report. Rendering extensions included in Reporting Services are HTML, TIFF, XML, Excel, PDF, CSV, and Web archive.

replicated data

Data at the Subscriber that has been received from a Publisher.


A set of technologies for copying and distributing data and database objects from one database to another and then synchronizing between databases to maintain consistency.

Replication Conflict Viewer

Allows users to view and resolve conflicts that occurred during the replication process and to review the manner in which conflicts have been resolved.

Replication Monitor

Provides a systemic view of replication activity, focusing on the movement of data between the Publisher and the Subscribers. Replication Monitor is a tool for watching real-time activity, troubleshooting problems, and analyzing past replication activity.

replication scripting

The generation of .sql scripts that can be used to configure and disable replication.

replication topology

Defines the relationship between servers and copies of data and clarifies the logic that determines how data flows between servers.

report definition

An .rdl file that contains information about the query and layout for a Reporting Services report.

Report Definition Language

A set of instructions that describe layout and query information for a report. RDL is composed of XML elements that conform to an XML grammar created for Reporting Services.

report history

A collection of report snapshots that are created and saved over time.

report item

Any object, such as a text box, graphical element, or data region, that exists on a report layout.

report layout

1. In Report Designer, the placement of fields, text, and graphics within a report. 2. In Report Builder, the placement of fields and entities within a report, plus applied formatting styles.

report layout template

A pre-designed table, matrix, or chart report template in Report Builder.

report model

A metadata description of business data used for creating ad hoc reports in Report Builder.

report processing extension

A component in Reporting Services that is used to extend the report processing logic. The Report Processor component provided with Reporting Services includes the ability to process a fixed set of report items (list, table, matrix, chart, textbox, line, rectangle, and image). Reporting Services also supports the ability to extend this list of report items through custom report items defined in report processing extensions. You can build or purchase a third-party report processing extension to support data-bound controls that you embed in your reports.

report processor

A Reporting Services component that processes reports and report models.

report rendering

The action of combining the report layout with the data from the data source for the purpose of viewing the report.

report server

A location on the network where Report Builder is launched from and a report is saved, managed, and published.

report server administrator

A user who is assigned to the Content Manager role, the System Administrator role, or both for a report server.

report server database

A SQL Server relational database that provides internal storage for a report server instance or scale-out deployment.

report server execution account

The account under which the Report Server Web service and Report Server Windows service run.

report server folder namespace

A hierarchy that contains predefined and user-defined folders. The namespace uniquely identifies reports and other items that are stored in a report server. It provides an addressing scheme for specifying reports in a URL.

report snapshot

A report that contains data captured at a specific point in time. A report snapshot is actually a report definition that contains a dataset instead of query instructions.

ReportViewer controls

A Web server control and Windows Form control that provides embedded report processing in ASP.NET and Windows Forms applications.


A database containing information models that, in conjunction with the executable software, manage the database.


When a Subscriber publishes to another Subscriber data that it has received from a Publisher.


A Subscriber that publishes data that it has received from a Publisher.

resolution strategy

A set of criteria that the repository engine evaluates sequentially when selecting an object, where multiple versions exist and version information is unspecified in the calling program.


A multiphase process that copies all the data and log pages from a specified backup to a specified database (the data-copy phase) and rolls forward all the transactions that are logged in the backup (the redo phase). At this point, by default, a restore rolls back any incomplete transactions (the undo phase). This completes the recovery of the database and makes it available to users.

restore sequence

A sequence of one or more restore commands that, typically, initializes the contents of the database, files, or pages that are being restored (the data-copy phase); rolls forward logged transactions (the redo phase); and rolls back uncommitted transactions (the undo phase).

result set

The set of rows returned from a SELECT statement. The format of the rows in the result set is defined by the column-list of the SELECT statement.

return parameters

A legacy term for stored procedure output parameters, used in the Open Data Services and DB-Library APIs.

reusable bookmark

A bookmark that can be consumed from a rowset for a given table and used on a different rowset of the same table to position on a corresponding row.


See Other Term: referential integrity


See Other Term: row identifier

right outer join

A type of outer join in which all rows in the table on the right in the JOIN clause are included. When rows in the right table are not matched in the table on the left, all result set columns that come from the table on the left are assigned a value of NULL.


See Other Term: relational OLAP


1. A SQL Server security account that is a collection of other security accounts that can be treated as a single unit when managing permissions. A role can contain SQL Server logins, other roles, and Windows logins or groups. 2. In Analysis Services, a role uses Windows security accounts to limit scope of access and permissions when users access databases, cubes, dimensions, and data mining models. 3. In a database mirroring session, the principal server and mirror server perform complementary principal and mirror roles. Optionally, the role of witness is performed by a third server instance.

role assignment

In Reporting Services, a role assignment is a security policy that determines whether a user or group can access a specific item and perform an operation. A role assignment consists of a user or group account name and one or more role definitions.

role definition

In Reporting Services, a named collection of tasks that defines the operations a user can perform on a report server.

role switching

In a database mirroring session, the taking over of the principal role by the mirror.

roll back

To reverse changes that were made by transactions that were uncommitted at the point in time to which a database is being recovered.

roll forward

To apply logged changes to the data in a roll forward set to bring the data forward in time.

roll forward set

The set of data restored by a restore sequence. A roll forward set is defined by restoring a series of one or more data backups.


In an SQL table, a single occurrence of the object modeled by the table. For example, in the AdventureWorks sample database, the Employee table models the employees of the Adventure Works Cycles company. Each row in the table records all the information about a specific employee such as an employee identification number, job title, and the date that employee was hired.

row aggregate function

A function that generates summary values, which appear as additional rows in the query results (unlike aggregate function results that appear as new columns). It lets you see detail and summary rows in one set of results. Row aggregate functions (SUM, AVG, MIN, MAX, and COUNT) are used in a SELECT statement with the COMPUTE clause.

row filter

In replication, a filter that allows you to restrict the data replicated to a Subscriber based on a WHERE clause. A row filter can be static or parameterized.

row ID

See Other Term: row identifier

row identifier

1. A column or set of columns used to distinguish any single row from every other row in the table. 2. In a heap, a pointer to the row. The pointer is built from the file identifier (ID), page number, and number of the row on the page.

row lock

A lock on a single row in a table.

row versioning

1. With cursors, the process in which the timestamp column of a row is used to determine whether data has been modified after being read into a cursor. If the data row does not have a timestamp column, row versioning is not used. 2. With transaction isolation, when a row versioning-based isolation level is enabled, the process in which the Database Engine maintains versions of data rows affected by data manipulation language (DML) execution. By choosing the appropriate isolation level, applications use row versions to query and retrieve a transactionally consistent snapshot of the data as it existed at the start of the transaction or query without acquiring locks on the data.

row-overflow data

Data of type varchar, nvarchar, varbinary, or sql_variant that is stored off the main data page of a table or index because the combined widths of these columns exceeds the limit of 8,060 bytes per row.


The OLE DB object that is used to contain a result set. It also exhibits cursor behavior depending on the rowset properties set by an application.


1. A database object that is bound to columns or alias data types, and specifies which data values are acceptable in a column. CHECK constraints provide the same functionality and are preferred because they are in the SQL-92 standard. 2. In Analysis Services, a rule specifies restrictions such as Unrestricted, Fully Restricted, or Custom for security read and read/write role permissions.

rule firing

The process of executing one of the application rules (event chronicle rules, subscription event rules, and subscription scheduled rules) defined in the application definition file. The rules are Transact-SQL statements that process notification data.


Indicates what values are valid to be stored in a table. This is referred to as domain integrity.


A marker that allows an application to roll back part of a transaction if a minor error is encountered. The application must still commit or roll back the full transaction when it is complete.

scalable shared database

A configuration in SQL Server that allows for clients to access a database simultaneously on multiple server instances. In this configuration, a read-only disk that contains the database is mounted onto multiple servers, and the database is attached to an instance of SQL Server on each server.


A single-value field, as opposed to an aggregate.

scalar aggregate

An aggregate function, such as MIN(), MAX(), or AVG(), that is specified in a SELECT statement column list that contains only aggregate functions. When the column list contains only aggregate functions, then the result set has only one row giving the aggregate values calculated from the source rows that match the WHERE clause predicates.

scheduled backup

An automatic backup performed by SQL Server Agent when defined and scheduled as a job.

schema rowset

A special OLE DB or Analysis Services rowset that reports catalog information for objects in databases or multidimensional cubes. For example, the OLE DB schema rowset DBSCHEMA_COLUMNS describes columns in tables, and the Analysis Services MDSCHEMA_MEASURES schema rowset describes the measures in a cube.

schema snapshot

In replication, a snapshot that includes the schema for published objects as well as objects required by replication (systems tables, triggers, and so on), but not user data.


A collection of Transact-SQL statements used to perform an operation. Transact-SQL scripts are stored as files, usually with the .sql extension.


The ability to move around a cursor in directions other than forward-only. Users can move up and down the cursor.

search condition

In a WHERE or HAVING clause, predicates that specify the conditions that the source rows must meet to be included in the SQL statement. For example, the statement SELECT * FROM Employees WHERE Title = 'Sales Representative' returns only those rows that match the search condition: Title = 'Sales Representative'.

secondary database

In log shipping, a copy of the primary database that was created by restoring a database backup, with NORECOVERY or with STANDBY, on a separate server instance (the secondary server). Log backups from the primary database are restored at set intervals onto the secondary database.

secondary server

In a log shipping configuration, the server instance on which the secondary database resides. At set intervals, the secondary server copies the latest log backup from the primary database and restores the log to the secondary database. The secondary server is a warm standby server.


An object that can have a security descriptor.

Secure Sockets Layer (SSL)

A protocol that supplies secure data communication through data encryption and decryption.

security extension

A component in Reporting Services that authenticates a user or group to a report server. The default security extension in Reporting Services is Windows authentication. Custom extensions can be created to support forms-based authentication or to integrate with third-party single sign-on technologies.

security identifier

A unique value that identifies a user who is logged on to the security system. SIDs can identify either one user or a group of users.


A data mining technique that analyzes data to discover mutually exclusive collections of records that share similar attributes sets. A segmentation algorithm can use unsupervised learning techniques, such as clustering, or supervised learning for a specific prediction field.


1. The Transact-SQL statement used to return data to an application or another Transact-SQL statement, or to populate a cursor. The SELECT statement returns a tabular result set consisting of data that is typically extracted from one or more tables. The result set contains only data from rows that match the search conditions specified in WHERE or HAVING clauses. 2. In Analysis Services, the Multidimensional Expressions (MDX) statement used to query cubes and return recordsets of multidimensional data.

select list

The SELECT statement clause that defines the columns of the result set returned by the statement. The select list is a comma-separated list of expressions, such as column names, functions, or constants.

Select query

A query that returns rows into a result set from one or more tables. A Select query can contain specifications for the columns to return, the rows to select, the order to put the rows in, and how to group (summarize) information.


A join in which records from a table are combined with other records from the same table when there are matching values in the joined fields. A self-join can be an inner join or an outer join. In database diagrams, a self-join is called a reflexive relationship.

Semantic Model Definition Language

A set of instructions that describe layout and query information for reports created in Report Builder. SMDL is composed of XML elements that conform to an XML grammar created for the Reporting Services Report Builder component.

semiadditive measure

A measure that can be summed along one or more, but not all, dimensions in a cube. For example, a quantity-on-hand measure of inventory can be summed along the geography dimension to produce a total quantity on hand for all warehouses, but it cannot be summed along the time dimension because the measure specifies snapshot quantities periodically in time.

send queue

In database mirroring, any unsent log of the principal database that has accumulated on the log disk of the principal database while it waits to be sent to the mirror server.

sensitive cursor

A cursor that can reflect data modifications made to underlying data by other users while the cursor is open. Updates, deletes, and inserts made by other users are reflected in the sensitive cursor. Sensitive cursors are typically used in Transact-SQL batches, stored procedures, and triggers by omitting the INSENSITIVE keyword on the DECLARE CURSOR statement.

sequenced collection

A collection of destination objects of a sequenced relationship object.

sequenced relationship

A relationship in a repository that specifies explicit positions for each destination object within the collection of destination objects.


The highest transaction isolation level. Serializable transactions lock all rows they read or modify to ensure the transaction is completely isolated from other tasks. This guarantees that a series of serializable transactions will always produce the same results if run in the same sequence.

server cursor

A cursor implemented on the server. The cursor itself is built at the server, and only the rows fetched by an application are sent to the client.

server name

A name that uniquely identifies a server computer on a network. SQL Server applications can connect to a default instance of SQL Server by specifying only the server name. SQL Server applications must specify both the server name and instance name when connecting to a named instance on a server.

server role

In Analysis Services, a role used to grant server-wide security privileges to a user.

server subscription

A subscription to a merge publication that uses an assigned priority value for conflict detection and resolution. Referred to as a global subscription in previous versions of SQL Server.

Service Broker

Provides facilities for storing message queues in a SQL Server database.

service principal name

The name by which a client uniquely identifies an instance of a service. If you install multiple instances of a service on computers throughout a forest, each instance must have its own SPN. A given service instance can have multiple SPNs if there are multiple names that clients might use for authentication


An ordered collection of tuples with the same dimensionality.

Setup initialization file

A text file, using the Windows .ini file format, that stores configuration information allowing SQL Server to be installed without a user having to be present to respond to prompts from the Setup program.

severity level

A number that indicates the relative significance of an error that is generated by the SQL Server Database Engine. Values range from informational (1) to severe (25).

shared dimension

A dimension created within a database that can be used by any cube in the database.

shared lock

A lock created by nonupdate (read) operations. Other users can read the data concurrently, but no transaction can acquire an exclusive lock on the data until all the shared locks have been released.


A report showing the execution plan for an SQL statement. SET SHOWPLAN_TEXT and SET SHOWPLAN_ALL produce textual showplan output. SET SHOWPLAN_XML, produces XML output. SQL Server Management Studio can display showplan information as a graphical tree. SET STATISTICS PROFILE produces showplan information in textual form, but also executes the query. SET STATISTICS XML also produces showplan output, but in XML format, and executes the query.


A member in a dimension hierarchy that is a child of the same parent as a specified member. For example, in a Time dimension with Year and Month levels, the members January 1997 and February 1997 are siblings.

simple recovery model

A database recovery mode that minimally logs all transactions, enough to help ensure database consistency after a system crash or after restoring a data backup. The database is recoverable only up to the time of its most recent data backup. Restoring individual pages is not supported.

single-user mode

A state in which only one user can access a resource. Both SQL Server instances and individual databases can be put into single-user mode.


A subset of the data in a cube, specified by limiting one or more dimensions by members of the dimension. For example, facts for a particular year constitute a slice of multiyear data.

smart tag

A smart tag exposes key configurations directly on the design surface to enhance overall design-time productivity in Visual Studio.

smart tag panel

A smart tag panel is a designer-managed UI that exposes component configurations as a set of smart tag entries.

smart tags anchor

A smart tag anchor is a button that is displayed at the top-right edge of a component on the Windows Forms design surface. The anchor, when clicked, opens the smart tag panel.


See Other Term: Semantic Model Definition Language


See Other Term: Simple Mail Transfer Protocol


See Other Term: report snapshot

Snapshot Agent

Prepares snapshot files containing schema and data of published tables, stores the files in the snapshot folder, and inserts synchronization jobs in the publication database.

Snapshot Agent utility

Configures and triggers the Snapshot Agent, which prepares snapshot files containing schema and data of published tables and database objects.

snapshot replication

Snapshot replication distributes data exactly as it appears at a specific moment in time and does not monitor for updates to the data. When synchronization occurs, the entire snapshot is generated and sent to Subscribers.

snapshot share

In replication, a share available for the storage of snapshot files. Snapshot files contain the schema and data for published tables.

snowflake schema

An extension of a star schema such that one or more dimensions are defined by multiple tables. In a snowflake schema, only primary dimension tables are joined to the fact table. Additional dimension tables are joined to primary dimension tables.

solve order

The order of evaluation (from highest to lowest solve order) and calculation (from lowest to highest solve order) for calculated members, custom members, custom rollup formulas, and calculated cells in a single calculation pass of a multidimensional cube. Solve order is used to determine formula precedence when calculating values for cells in multidimensional cubes, but only within a single calculation pass.

sort order

The set of rules in a collation that define how characters are evaluated in comparison operations, and the sequence in which they are sorted.


An Integration Services data flow component that extracts data from a data store, such as files and databases.

source and target

A browsing technique in which a source object is used to retrieve its target object or objects through their relationship.

source cube

The cube on which a linked cube is based.

source database

In data warehousing, the database from which data is extracted for use in the data warehouse.

source object

The single object to which all objects in a particular collection are connected by way of relationships that are all of the same relationship type. For destination collections, the source object is the destination object. For origin collections, the source object is the origin object.

source partition

An Analysis Services partition that is merged into another and is deleted automatically at the end of the merger process.


The relative percentage of a multidimensional structure's cells that do not contain data. Analysis Services stores only cells that contain data. A sparse cube requires less storage than a dense cube of identical structure design.


See Other Term: Structured Query Language (SQL)

SQL collation

A set of SQL Server collations whose characteristics match those of commonly-used code page and sort order combinations from earlier versions of SQL Server. SQL collations are compatibility features that let sites choose collations that match the behavior of their earlier systems.

SQL database

A database based on Structured Query Language (SQL).

SQL expression

Any combination of identifiers, values, and operators that evaluates to a single value. For example, constants, literal values, functions, variables, subqueries, and column names are expressions.

SQL Mail

A component of SQL Server that allows SQL Server to send and receive mail messages through the built-in Windows NT or Windows 2000 Messaging Application Programming Interface (MAPI). A mail message can consist of short text strings, the output from a query, or an attached file.

SQL query


SQL Server Authentication

One of two mechanisms for validating attempts to connect to instances of SQL Server. Users must specify a SQL Server login ID and password when they connect. The SQL Server instance verifies that the login ID and password combination are valid before allowing the connection to succeed.

SQL Server Event Forwarding Server

A central instance of SQL Server that manages SQL Server Agent events forwarded to it by other instances. Enables central management of SQL Server events.

SQL Server event provider (Notification Services)

A stored procedure-based event provider that gathers data from SQL Server and submits it to the event table by using the standard Notification Services event collection stored procedures.

SQL statement

An SQL or Transact-SQL command, such as SELECT or DELETE, that performs some action on data.


The version of the SQL standard published in 1992. The international standard is ISO/IEC 9075:1992 Database Language SQL. The American National Standards Institute (ANSI) also published a corresponding standard (Data Language SQL X3.135-1192), so SQL-92 is sometimes referred to as ANSI SQL in the United States.


See other term: Secure Sockets Layer (SSL)

standby file

In a restore operation, a file that is used during the undo phase to hold a "copy-on-write" pre-image of pages that are to be modified. The standby file allows for the undo pass to be reverted so that the uncommitted transactions can be brought back. In SQL Server 2000, this is called an undo file.

standby server

A server instance that contains a copy of a database that can be brought online if the source copy of the database becomes unavailable.

star join

1. A join between a fact table (typically a large fact table) and at least two dimension tables. The fact table is joined with each dimension table on a dimension key. SQL Server considers special index manipulation strategies on these queries to minimize access to the fact table. 2. An example of a schema participating in a star join query could be a sales table, the fact table (containing millions of rows), a product table, (containing the description of several hundred products), and a store table (containing several dozen store names). In this example, the product and store tables are dimension tables. A query for selecting sales data for a small set of stores and a subset of products restricted by attributes not present in the sales database is an ideal candidate for the star query optimization.

star schema

A relational database structure in which data is maintained in a single fact table at the center of the schema with additional dimension data stored in dimension tables. Each dimension table is directly related to and usually joined to the fact table by a key column. Star schemas are used in data warehouses.

static cursor

A cursor that shows the result set exactly as it was at the time the cursor was opened. Static cursors do not reflect updates, deletes, or inserts that are made to underlying data while the cursor is open. They are sometimes referred to as snapshot cursors.

static row filter

A filter available for all types of replication that allows you to restrict the data replicated to a Subscriber based on a WHERE clause. The same partition of data is delivered to all Subscribers.


In Full-Text Search, for a given language, a stemmer generates inflectional forms of a particular word based on the rules of that language. Stemmers are language specific.

stored procedure

A precompiled collection of Transact-SQL statements that are stored under a name and processed as a unit. SQL Server supplies stored procedures for managing SQL Server and displaying information about databases and users. SQL Server-supplied stored procedures are called system stored procedures.


A set of contiguous bytes that contain a single character-based or binary data value. In character strings, each byte or pair of bytes represents a single alphabetic letter, special character, or number. In binary strings, the entire value is considered to be a single stream of bits that do not have any inherent pattern. For example, the constant 'I am 32.' is an 8-byte character string, while the constant 0x0205efa3 is a 4-byte binary string.

string functions

Functions that perform operations on character or binary strings. Built-in string functions return values commonly needed for operations on character data.

striped media set

A media set that uses multiple devices, among which each backup is distributed.

Structured Query Language (SQL)

A language used to insert, retrieve, modify, and delete data in a relational database, designed specifically for database queries. SQL also contains statements for defining and administering the objects in a database. SQL is the language supported by most relational databases, and is the subject of standards published by the International Standards Organization (ISO) and the American National Standards Institute (ANSI). SQL Server uses a version of the SQL language called Transact-SQL.


A subset of a cube that represents a filtered view of the cube, with the (All) displaying the visual totals of the members in the subcube.


To request data from a Publisher.


A database instance that receives replicated data. A Subscriber can receive data from multiple Publishers and publications. Depending on the type of replication chosen, the Subscriber can also pass data changes back to the Publisher or republish the data to other Subscribers.

subscribing server

A server running an instance of Analysis Services that stores a linked cube.


A request for a copy of a publication to be delivered to a Subscriber. The subscription defines what publication will be received, where, and when. There are two types of subscriptions: push and pull.

subscription database

A database at the Subscriber that receives data and database objects published by a Publisher.

subscription event rule

A rule that processes information for event-driven subscriptions. It might contain notification generation rules or chronicle update rules. This type of rule is fired each time a corresponding batch of events is submitted.

subscription expiration period

See Other Term: publication retention period

subscription management application (Notification Services)

The application that Subscribers use to submit and manage their subscriptions. For each instance or application, a developer can create a custom interface for managing subscriptions. This application must use Notification Services APIs to submit data to the system.

subscription scheduled rule

One or more Transact-SQL statements that process information for scheduled subscriptions. The rule can contain notification generation rules or chronicle update rules. This type of rule is fired each time a scheduled subscription is due for processing.


A selection of tables and the relationship lines between them that is part of a larger database diagram. This selection can be copied to a new database diagram. This is called subsetting the diagram.

symmetric key

A single key that is used with symmetric encryption algorithms for both encryption and decryption.


1. In replication, the process of data and schema changes being propagated between the Publisher and Subscribers after the initial snapshot has been applied at the Subscriber. 2. In database mirroring, when a mirroring session starts or resumes, the process in which log records of the principal database that have accumulated on the principal server are sent to the mirror server, which writes these log records to disk as quickly as possible to catch up with the principal server.

system databases

A set of five databases present in all instances of SQL Server that are used to store system information. The msdb database is used by SQL Server Agent to record information on jobs, alerts, and backup histories. The model database is used as a template for creating all user databases. The tempdb database stores transient objects that only exist for the length of a single statement or connection, such as worktables and temporary tables or stored procedures. The master database stores all instance-level metadata, and records the location of all other databases. The Resource database contains all the system objects that are included with SQL Server, such as system stored procedures and system tables.

system functions

A set of built-in functions that perform operations on and return the information about values, objects, and settings in SQL Server.

system stored procedures

A set of SQL Server-supplied stored procedures that can be used for actions such as retrieving information from the system catalog or performing administration tasks.

system tables

Built-in tables that form the system catalog for SQL Server. System tables store all the metadata for an instance of SQL Server, including configuration information and definitions of all the databases and database objects in the instance. Users should not directly modify any system table.


1. A two-dimensional object, which consists of rows and columns, that stores data about an entity modeled in a relational database. 2. A data region on a report layout that displays data in a columnar format.

table data region

A report item on a report layout that displays data in a columnar format.

table lock

A lock on a table including all data and indexes.

table scan

A data retrieval operation where the Database Engine must read all the pages in a table to find the rows that qualify for a query.

table-level constraint

Constraints that allow various forms of data integrity to be defined on one column (column-level constraint) or several columns (table-level constraints) when the table is defined or altered. Constraints support domain integrity, entity integrity, and referential integrity, as well as user-defined integrity.

tabular data stream (TDS)

The SQL Server internal client/server data transfer protocol. TDS allows client and server products to communicate regardless of operating-system platform, server release, or network transport.

tail-log backup

A log backup that is taken in preparation for a database restore to capture the log that has not yet been backed up. A tail-log backup helps prevent work loss after a failure.

tape backup

A SQL Server backup operation that writes to any tape device supported by Windows XP or Windows Server 2003. The tape device must be physically attached to the computer that is running the instance of SQL Server.

target partition

An Analysis Services partition into which another is merged, and which contains the data of both partitions after the merger.

target server

A server that receives jobs from a master server.


1. In Integration Services, a control flow element that performs a discrete type of work in a package. 2. In Reporting Services, actions that a user or administrator can perform. Tasks are predefined.

tempdb database

The database that provides a storage area for temporary tables, temporary stored procedures, and other temporary working storage needs.

temporary stored procedure

A procedure placed in the temporary database, tempdb, and erased at the end of the session.

temporary table

A table placed in the temporary database, tempdb, and erased at the end of the session.


An operating system component that lets the logic of multiuser applications be performed as several separate, asynchronous execution paths. The SQL Server relational Database Engine runs multiple threads to make use of multiple processors. The use of threads also helps ensure that work is being performed for some user connections even when other connections are blocked (for example, when waiting for a disk read or write operation to complete).

time dimension

A dimension that breaks time down into levels such as Year, Quarter, Month, and Day. In Analysis Services, a special type of dimension created from a date/time column.


In Full-Text Search, a word or a character string identified by the word breaker.


In text mining or Full-Text Search, the process of identifying meaningful units within strings, either at word boundaries, morphemes, or stems, so that related tokens can be grouped. For example, although San Francisco is two words, it could be treated as a single token.


A SQL Server application with a graphical user interface used to perform common tasks.

trace file

A file used by SQL Server Profiler to record monitored events.

tracer token

In transactional replication, a feature that provides a convenient way to measure latency and to validate the connections between the Publisher, Distributor, and Subscribers. A token is written to the transaction log of the publication database, marked as though it were a typical replicated transaction, and sent through the system.

training data set

A set of known and predictable data used to train a data mining model.


An attribute that describes an entity.

trait phrasing

A way of expressing a relationship in which a minor entity describes a major entity.


A group of database operations combined into a logical unit of work that is either wholly committed or rolled back. A transaction is atomic, consistent, isolated, and durable.

transaction log

A database file in which all changes to the database are recorded. SQL Server uses transaction logs during recovery.

transaction processing

Data processing used to efficiently record business activities, called transactions, that are of interest to an organization (for example, sales, orders, or money transfers). Typically, online transaction processing (OLTP) systems perform large numbers of relatively small transactions.

transaction retention period

See Other Term: distribution retention period

transaction rollback

Rollback of a user-specified transaction to the last savepoint inside a transaction or to the beginning of a transaction.

transactional replication

A type of replication that typically starts with a snapshot of the publication database objects and data. As soon as the initial snapshot is taken, subsequent data changes and schema modifications made at the Publisher are usually delivered to the Subscriber as they occur (in near real time). The data changes are applied to the Subscriber in the same order and within the same transaction boundaries as they occurred at the Publisher; therefore, within a publication, transactional consistency is guaranteed.


The language containing the commands used to administer instances of SQL Server, create and manage all objects in an instance of SQL Server, and to insert, retrieve, modify and delete all data in SQL Server tables. Transact-SQL is an extension of the language defined in the SQL standards published by the International Standards Organization (ISO) and the American National Standards Institute (ANSI).

Transact-SQL cursor

A server cursor defined by using the Transact-SQL DECLARE CURSOR syntax. Transact-SQL cursors are intended for use in Transact-SQL batches, stored procedures, and triggers.


1. In data warehousing, the process of changing data extracted from source data systems into arrangements and formats consistent with the schema of the data warehouse. 2. In Integration Services, a data flow component that aggregates, merges, distributes, and modifies column data and rowsets.


A stored procedure that executes in response to a data manipulation language (DML) or data definition language (DDL) event.

trusted connection

A Windows network connection that can be opened only by users who have been authenticated by the network. The users are identified by their Windows login ID and do not have to enter a separate SQL Server login ID.


See Other Term: target server


Uniquely identifies a cell, based on a combination of attribute members from every attribute hierarchy in the cube.

two-phase commit

A process that ensures transactions that apply to more than one server are completed on all servers or on none.

unbalanced hierarchy

A hierarchy in which one or more levels do not contain members in one or more branches of the hierarchy. For example, the state or province level in a geography hierarchy contains no members for countries that do not have states or provinces. An unbalanced hierarchy is also called a ragged hierarchy.

underlying table

A table referenced by a view, cursor, or stored procedure.


The phase during database recovery that rolls back changes made by any transactions that were uncommitted when the redo phase of recovery finished.

unenforced relationship

A link between tables that references the primary key in one table to a foreign key in another table, and which does not check the referential integrity during INSERT and UPDATE transactions. An unenforced relationship is represented in a database diagram by a dashed line.


Unicode defines a set of letters, numbers, and symbols that SQL Server recognizes in the nchar, nvarchar, and ntext data types. It is related to but separate from character sets. Unicode has more than 65,000 possible values compared to a character set's 256, and takes twice as much space to store. Unicode includes characters for most languages.

Unicode collation

This acts as a sort order for Unicode data. It is a set of rules that determines how SQL Server compares, collates, and presents Unicode data in response to database queries.

Unicode format

Data stored in a bulk copy data file using Unicode characters.

Union query

A query that combines two tables by performing the equivalent of appending one table onto the other.

UNIQUE constraints

Constraints that enforce entity integrity on a nonprimary key. UNIQUE constraints ensure that no duplicate values are entered and that an index is created to enhance performance.

unique index

An index in which no two rows are permitted to have the same index value, thus prohibiting duplicate index or key values. The system checks for duplicate key values when the index is created and checks each time data is added with an INSERT or UPDATE statement.


A 4-byte column that the SQL Server Database Engine automatically adds to a row to make each index key unique. This column and its values are used internally and cannot be seen or accessed by users.


In Integration Services, the process of creating a more normalized dataset by expanding data columns in a single record into multiple records.


The act of modifying one or more data values in an existing row or rows, typically by using the UPDATE statement. Sometimes, the term update refers to any data modification, including insert, update, and delete operations.

update lock

A lock placed on resources (such as row, page, table) that can be updated. Updated locks are used to prevent a common form of deadlock that occurs when multiple sessions are locking resources and are potentially updating them later.

Update query

A query that changes the values in columns of one or more rows in a table.

update statistics

A process that recalculates information about the distribution of key values in specified indexes. These statistics are used by the query optimizer to determine the most efficient way to execute a query.

user (account)

A SQL Server security account or identifier that represents a specific user in a database.

user database

A database created by a SQL Server user and used to store application data. Most users connecting to instances of SQL Server reference user databases only, not system databases.

user instance

An instance of SQL Server Express that is generated by the parent instance on behalf of a user. A parent instance is the primary instance of SQL Server Express that is running as a service, such as SQLExpress. The user instance runs as a user process under the security context of that user, and is used to enable Xcopy scenarios for non-administrator users who are not members of the dbcreator fixed server role. The user instance feature is also referred to as Run As Normal User (RANU).

user-defined aggregate (function)

An aggregate function that is created by referencing a SQL Server assembly. The implementation of the user-defined aggregate function is defined in an assembly that is created in the .NET Framework common language runtime (CLR).

user-defined event

A type of message, defined by a user, that can be traced by SQL Server Profiler or used to fire a custom alert. Typically, the user is the system administrator.

user-defined function

1. In SQL Server, a Transact-SQL function defined by a user. Functions encapsulate frequently performed logic in a named entity that can be called by Transact-SQL statements instead of recoding the logic in each statement. 2. In Analysis Services, a function defined in a Microsoft ActiveX library created using a Component Object Model (COM) automation language such as Visual Basic or Visual C++. Such libraries can be registered with Analysis Services and their functions called from Multidimensional Expressions (MDX) queries.

user-defined hierarchy

A balanced hierarchy of attribute hierarchies that facilitates browsing of cube data by users.


A SQL Server application run from a command prompt to perform common tasks.

vacuumer (Notification Services)

The component that removes expired data from Notification Services tables.

vacuuming (Notification Services)

The process of clearing obsolete data from a Notification Services application according to a schedule defined in the application definition file.

validation (semantic)

The process of confirming that the elements of an XML file are logically valid. For example, semantic validation might confirm that a value is numeric and within a specified range.

validation (syntactic)

The process of confirming that an XML file conforms to its schema.

value expression

An expression in Multidimensional Expressions (MDX) that returns a value. Value expressions can operate on sets, tuples, members, levels, numbers, or strings. For example, set value expressions operate on member, tuple, and set elements to yield other sets.


1. In Integration Services, stores values that can be used in scripts, expressions, and property expressions to set column values and the properties of package objects. 2. Defined entities that are assigned values. A local variable is defined with a DECLARE@localvariable statement and assigned an initial value within the statement batch where it is declared with either a SELECT or SET@localvariable statement.

vertical filtering

Filtering columns from a table. When used as part of replication, the table article created contains only selected columns from the publishing table.

vertical partitioning

To segment a single table into multiple tables based on selected columns. Each of the multiple tables has the same number of rows but fewer columns.

view generation

A repository engine feature that is used to create relational views based on classes, interfaces, and relationships in an information model.

visual total

A displayed, aggregated cell value for a dimension member that is consistent with the displayed cell values for its displayed children. The visual total of a cell can vary from the actual total if some children of the cell are hidden. For example, if the aggregate function is SUM, the displayed cell value for Spain is 1000, and the displayed cell value for Portugal is 2000, the visual total for Iberia is 3000.

warm standby server

A standby server that contains a copy of a database that is asynchronously updated, and that can be brought online fairly quickly. A log shipping secondary server is a warm standby server whose database is automatically updated from log backups that are created at set intervals. An unsynchronized mirror server can also be used as a warm standby server, with possible data loss.

Web synchronization

In merge replication, a feature that lets you replicate data by using the HTTPS protocol.

wildcard characters

Characters, including underscore (_), percent (%), and brackets ([ ]), used with the LIKE keyword for pattern matching.

wildcard search

The use of placeholders (such as * or ?) to search for data in a table or field. For example, you might use the string Smith* to search the Last Name field in a database for all records in which the last name starts with Smith, including Smith, Smithson, Smithlin, and so on.

Windows collation

A set of rules that determines how SQL Server sorts character data. A collation is specified by name in the Windows Control Panel and in SQL Server 2000 during Setup.

Windows Management Instrumentation

An interface that provides information about objects in a managed environment. The Windows Management Instrumentation extensions for SQL are called WMI Query Language (WQL).

witness server

In database mirroring, the server instance that monitors the status of the principal and mirror servers. By default, the witness server can initiate automatic failover if the principal server fails. A database mirroring session can have only one witness server, which is optional.


See Other Term: Windows Management Instrumentation

WMI Query Language

A subset of ANSI SQL with semantic changes adapted to Windows Management Instrumentation (WMI).

word breaker

In Full-Text Search, for a given language, a word breaker tokenizes text based on the lexical rules of the language.

word generation

The process of determining other forms of the word(s) specified in a search. The Microsoft Search Service currently implements inflectional word generation. For example, if the word swim is specified, SQL Server also searches for swam and swimming.


In text mining or Full-Text Search, the process of separating strings at word boundaries. The definition of a word boundary differs greatly among natural languages and poses significant problems for natural language information retrieval.


See Other Term: WMI Query Language

write back

To update a cube cell value, member, or member property value.

write enable

To change a cube or dimension so that users in cube roles with read/write access to the cube or dimension can change its data.

write-ahead log

A transaction logging method in which the log is always written prior to the data.


A deployment feature, supported only by SQL Server Express, that allows an application and a database file (.mdf) to be copied to another computer, or to a different location on the same computer, without additional configuration.

XML Schema definition language (XSD)

A schema language. An XML Schema defines the elements, attributes, and data types that conform to the World Wide Web Consortium (W3C) XML Schema Part 1: Structures Recommendation for the XML Schema Definition Language. The W3C XML Schema Part 2: Datatypes Recommendation is the recommendation for defining data types used in XML schemas. The XML Schema definition language enables you to define the structure and data types for XML messages.


See Other Term: XML Schema definition language (XSD)


See Other Term: Extensible Stylesheet Language (XSL)


See Other Term: Extensible Stylesheet Language Transformations (XSLT)


A message that was not processed by an orchestration. It is not in the Suspended queue or anywhere else where it will be retried.

See Also

Other Resources

English Glossary of Terms

Help and Information

Getting SQL Server 2005 Assistance