What's New and Changed

This section provides descriptions about and links to the SQL Server Protocols technical documents that are new or updated. New documents have not been previously released. Updated documents have been previously released and are revised to reflect changes in functionality.

New Documentation

The following new documents were first released in October 2019 for Microsoft SQL Server 2019. They may have since been revised and re-released, as indicated.

Specification	Description	Latest release
[MS-CPREST]: Control Plane REST API	Specifies an HTTP-based web service API that deploys data services and applications into a managed cluster environment. This protocol then uses management service APIs to manage high-value data stored in relational databases that have been integrated with high-volume data resources within a dedicated cluster. This document has been updated to reflect SQL Server 2019 Cumulative Updates as follows: To define new configuration settings allowed by a big data cluster, including the security settings to use when a cluster is deployed with Active Directory. To clarify the availability of customized configuration settings for the Apache Spark and Apache Hadoop components that are running in a big data cluster. To specify functionality that allows mounting of the default Kubernetes service account on each pod in a big data cluster. To add configuration-related APIs for the services and resources deployed in the big data cluster. To provide details about the key management service (KMS) settings that are used to configure the main encryption keys for encrypting data at rest in a big data cluster. This document has also been revised as follows: To introduce the new JSON Elements section, in which the structure is based on the organization of the schemas that define and manage the big data cluster. To reflect the move of the examples initially provided in the methods' Request/Response Body subsections of the Message Processing Events and Sequencing Rules section into the Protocol Examples section. To define the Big Data Cluster Upgrade schema and to define the spark resource in the Big Data Cluster Spec schema. To revise the Update KMS Configuration Request schema and the Show KMS Configuration Response schema. To further define the keyCreationTime element in the Show KMS Configuration Response schema.	November 2021
[MS-HMSHTTP]: Hive Metastore HTTP Protocol	Specifies a web service API that provides a lightweight interface for clients to read catalog metadata from a Hive Metastore database that has been deployed as a data service inside a managed cluster environment. The document has been reorganized to move the examples from the Message Processing Events and Sequencing Rules section to the Protocol Examples section. The content of those sections has also been revised for clarity and added detail.	July 2020

Updated Documentation

The following previously released documents were updated in October 2019 for SQL Server 2019 and may have since been revised and re-released, as indicated.

Specification	Description	Latest release
[MS-ODBCSTR]: ODBC Connection String Structure	Specifies the format of the connection string used in Open Database Connectivity (ODBC). This document has been updated to add a description of the new client-certificate authentication feature that provides users with an alternative to username-and-password authentication.	June 2021
[MS-RDL]: Report Definition Language File Format	Specifies the file format for SQL Server Report Definition Language (RDL), a file type that is used to represent the metadata for defining a report. This document has been updated to include Accessibility information about specifying the available ToolTip element to render alternative text (alt text) in reports.	July 2020
[MS-SCCSTR]: SqlClient Connection String Protocol	Specifies a method for Microsoft .NET Framework applications to specify the parameters to connect to a data source that enables developers to query, update, insert, and delete data on SQL Server. This document has been updated to include information about enhanced confidentiality and security through column encryption and enclave technologies.	June 2021
[MS-SSAS]: SQL Server Analysis Server Protocol	Specifies the SQL Server Analysis Services Protocol, which provides methods for a client to communicate with and to perform operations on an analysis server. This document has been updated as follows: To control the amount of memory that can be used during a query. To clarify the use of read-write mode for a database. To support termination of an ongoing subscription to Trace events. To add information about options for refreshing client application caches. To enable DAX optimization. To provide information about all the memory trackers that are active on a server. The document has been revised further to provide clarification of the Server, event_session, unary_expr, Database, and RegularMeasureGroupDimension complex types, and the DISCOVER_MEMORYUSAGE and DISCOVER_SESSIONS rowsets. In addition, the document has been revised to update the description of the MdpropMdxSubqueries property, including the addition of the MDPROPVAL_MSQ_DRILLTHROUGH value, and to clarify other content.	August 2021
[MS-SSAS-T]: SQL Server Analysis Server Tabular Protocol	Specifies an extension of the SQL Server Analysis Services protocol [MS-SSAS] by specifying the methods for a client to communicate with and perform operations on an analysis server that uses Tabular databases that are at compatibility level 1200 or higher. This document has been updated as follows: To enable the value of a calculation item to be calculated based on an expression. To introduce a query feature that represents a logical group of Partition and Expression objects. To prevent a measure from having the same name as a column in the model. To disable creation of implicit measures so that calculation groups can be created. To introduce the ability for a user to add custom behaviors to a measure based on its data type. To specify linguistic metadata as either XML or JSON content. To exclude a table from a refresh operation on a model. To provide the ordering column in a DAX query. The document has been revised further to provide clarification of various objects, including Model, Partition, Annotation, and ExtendedProperty. The document has also been updated to describe product behavior for the JSON attach command in accordance with SQL Server 2019 Cumulative Updates.	April 2021
[MS-SSSO]: SQL Server System Overview	Provides an overview of the client and server protocols used by SQL Server. This document covers protocols that are commonly shared by SQL Server components, and those protocols that are used only by specific components. This update provides information about big data clusters and the new protocols that are specified in [MS-CPREST] and [MS-HMSHTTP] and how these protocols interact with other protocols in the SQL Server database management system. In addition, this update provides information about the capability of SQL Server on Windows or Linux to provide two-phase commit functionality for distributed transactions by using an MSDTC service.	March 2020

In addition, the following documents were updated to add SQL Server 2019 and/or other Microsoft products, as appropriate, as applicable products:

[MS-BINXML], [MS-DSDIFFGRAM], [MS-OLEDBSTR], [MS-RGDI], [MS-RPL], [MS-RSWSRE2005],
[MS-RSWSRM2010], [MS-RSWSRMNM2005], [MS-SQLRS], [MS-SSCLRT], and [MS-SSTDS]