Retrieving Metadata from an Analytical Data Source

APPLIES TO:yesSQL Server Analysis ServicesnoAzure Analysis Services

Metadata is important to applications that retrieve and work with analytical data. When retrieving data from a relational data source, the dimensionality of such data is predictable, even with nested datasets. Result sets from a relational database are typically two-dimensional or scalar in structure. However, data retrieved from analytical data sources can be of variable dimensionality, organized along potentially deep hierarchies.

To handle the complexity of metadata retrieval from analytical data sources, ADOMD.NET provides two forms of metadata retrieval:

The Object Model
The ADOMD.NET object model is generally easier to use than schema rowsets. For most scenarios, you can access the metadata of various database objects just by using the object model. ADOMD.NET exposes the object model through the AdomdConnection.

For more information: Working with the ADOMD.NET Object Model

Schema Rowsets
A complete, but more difficult approach to retrieving metadata is through using schema rowsets. A schema rowset is an OLE DB rowset that encapsulates the description for all objects of a particular type in the database. Schema information in an analytical data source includes databases or catalogs available from the data source, cubes and mining models in a database, roles that exist for cubes at the data source, and so on. This metadata can be retrieved by using the GetSchemaDataSet method, passing in either a GUID or an XML for Analysis (XMLA) name.

For more information: Working with Schema Rowsets in ADOMD.NET

Each of these metadata retrieval methods access different types of metadata. The following table describes the different metadata available for each method, and the methods used to access it.

GUID (used in Schema Rowsets) XMLA Name (used in Schema Rowsets) ADOMD.NET Object Model
Actions MDSCHEMA_ACTIONS Rowset
Catalogs DBSCHEMA_CATALOGS Rowset
Columns DBSCHEMA_COLUMNS Rowset
Connections DISCOVER_CONNECTIONS
Cubes MDSCHEMA_CUBES Rowset AdomdConnection.Cubes
DataSources DISCOVER_DATASOURCES Rowset
DBConnections DISCOVER_DB_CONNECTIONS
Dimensions MDSCHEMA_DIMENSIONS Rowset AdomdConnection.Cubes[].Dimensions
DimensionStat DISCOVER_DIMENSION_STAT
Enumerators DISCOVER_ENUMERATORS Rowset
Functions MDSCHEMA_FUNCTIONS Rowset
Hierarchies MDSCHEMA_HIERARCHIES Rowset AdomdConnection.Cubes[].Dimensions[].Hierarchies
InputDataSources MDSCHEMA_INPUT_DATASOURCES Rowset
Instances DISCOVER_INSTANCES Rowset
Jobs DISCOVER_JOBS
Keywords DISCOVER_KEYWORDS Rowset (OLE DB for OLAP)
Kpis MDSCHEMA_KPIS Rowset AdomdConnection.Cubes[].KPIs
Levels MDSCHEMA_LEVELS Rowset AdomdConnection.Cubes[].Dimensions[].Hierarchies[].Levels
Literals DISCOVER_LITERALS Rowset
Locations DISCOVER_LOCATIONS
Locks DISCOVER_LOCKS
MasterKey DISCOVER_MASTER_KEY
MeasureGroupDimensions MDSCHEMA_MEASUREGROUP_DIMENSIONS Rowset
MeasureGroups MDSCHEMA_MEASUREGROUPS Rowset
Measures MDSCHEMA_MEASURES Rowset AdomdConnection.Cubes[].Measures
MemberProperties MDSCHEMA_PROPERTIES Rowset PropertyCollection available from most major ADOMD.NET objects.
Members MDSCHEMA_MEMBERS Rowset AdomdConnection.Cubes[].Dimensions[].Hierarchies[].Levels[].GetMembers()
MemoryGrant DISCOVER_MEMORYGRANT
MemoryUsage DISCOVER_MEMORYUSAGE
MiningColumns DMSCHEMA_MINING_COLUMNS Rowset AdomdConnection.MiningModels[].MiningModelColumns
MiningFunctions DMSCHEMA_MINING_FUNCTIONS Rowset
MiningModelContent DMSCHEMA_MINING_MODEL_CONTENT Rowset AdomdConnection.MiningModels[].MiningContentNodes
MiningModelContentPmml DMSCHEMA_MINING_MODEL_CONTENT_PMML Rowset
MiningModels DMSCHEMA_MINING_MODELS Rowset AdomdConnection.MiningModels
MiningModelXml DMSCHEMA_MINING_MODEL_XML Rowset
MiningServiceParameters DMSCHEMA_MINING_SERVICE_PARAMETERS Rowset AdomdConnection.MiningServices[].MiningServiceParameters
MiningServices DMSCHEMA_MINING_SERVICES Rowset AdomdConnection.MiningServices
MiningStructureColumns DMSCHEMA_MINING_STRUCTURE_COLUMNS Rowset AdomdConnection.MiningStructures[].MiningStructureColumns
MiningStructures DMSCHEMA_MINING_STRUCTURES Rowset AdomdConnection.MiningStructures
PartitionDimensionStat DISCOVER_PARTITION_DIMENSION_STAT
PartitionStat DISCOVER_PARTITION_STAT
PerformanceCounters DISCOVER_PERFORMANCE_COUNTERS
ProviderTypes DBSCHEMA_PROVIDER_TYPES Rowset
SchemaRowsets DISCOVER_SCHEMA_ROWSETS Rowset
Sessions DISCOVER_SESSIONS
Sets MDSCHEMA_SETS Rowset AdomdConnection.Cubes[].NamedSets
Tables DBSCHEMA_TABLES Rowset
TablesInfo DBSCHEMA_TABLES_INFO
TraceColumns DISCOVER_TRACE_COLUMNS
TraceDefinitionProviderInfo DISCOVER_TRACE_DEFINITION_PROVIDERINFO
TraceEventCategories DISCOVER_TRACE_EVENT_CATEGORIES
Traces DISCOVER_TRACES
Transactions DISCOVER_TRANSACTIONS
XmlaProperties DISCOVER_PROPERTIES Rowset
XmlMetadata DISCOVER_XML_METADATA Rowset

See Also

ADOMD.NET Client Programming
ADOMD.NET Client Programming
Analysis Services Schema Rowsets