sys.dm_db_incremental_stats_properties (Transact-SQL)
Applies to:
SQL Server
Returns properties of incremental statistics for the specified database object (table) in the current SQL Server database. The use of sys.dm_db_incremental_stats_properties
(which contains a partition number) is similar to sys.dm_db_stats_properties
which is used for non-incremental statistics.
This function was introduced in SQL Server 2014 (12.x) Service Pack 2 and SQL Server 2016 (13.x) Service Pack 1.
Syntax
sys.dm_db_incremental_stats_properties (object_id, stats_id)
Arguments
object_id
Is the ID of the object in the current database for which properties of one of its incremental statistics is requested. object_id is int.
stats_id
Is the ID of statistics for the specified object_id. The statistics ID can be obtained from the sys.stats dynamic management view. stats_id is int.
Table Returned
Column name | Data type | Description |
---|---|---|
object_id | int | ID of the object (table) for which to return the properties of the statistics object. |
stats_id | int | ID of the statistics object. Is unique within the table. For more information, see sys.stats (Transact-SQL). |
partition_number | int | Number of the partition containing the portion of the table. |
last_updated | datetime2 | Date and time the statistics object was last updated. For more information, see the Remarks section in this page. |
rows | bigint | Total number of rows in the table when statistics were last updated. If the statistics are filtered or correspond to a filtered index, the number of rows might be less than the number of rows in the table. |
rows_sampled | bigint | Total number of rows sampled for statistics calculations. |
steps | int | Number of steps in the histogram. For more information, see DBCC SHOW_STATISTICS (Transact-SQL). |
unfiltered_rows | bigint | Total number of rows in the table before applying the filter expression (for filtered statistics). If statistics are not filtered, unfiltered_rows is equal to the value returns in the rows column. |
modification_counter | bigint | Total number of modifications for the leading statistics column (the column on which the histogram is built) since the last time statistics were updated. This column does not contain information for memory-optimized tables. |
Remarks
sys.dm_db_incremental_stats_properties
returns an empty rowset under any of the following conditions:
object_id
orstats_id
is NULL.- The specified object is not found or does not correspond to a table with incremental statistics.
- The specified statistics ID does not correspond to existing statistics for the specified object ID.
- The current user does not have permissions to view the statistics object.
This behavior allows for the safe usage of sys.dm_db_incremental_stats_properties
when cross applied to rows in views such as sys.objects
and sys.stats
. This method can return properties for the statistics that correspond to each partition. To see the properties for the merged statistics combined across all partitions, use the sys.dm_db_stats_properties instead.
Statistics update date is stored in the statistics blob object together with the histogram and density vector, not in the metadata. When no data is read to generate statistics data, the statistics blob is not created, the date is not available, and the last_updated column is NULL. This is the case for filtered statistics for which the predicate does not return any rows, or for new empty tables.
Permissions
Requires that the user has select permissions on statistics columns or the user owns the table or the user is a member of the sysadmin
fixed server role, the db_owner
fixed database role, or the db_ddladmin
fixed database role.
Examples
A. Simple example
The following example returns the statistics for the PartitionTable
table described in the topic Create Partitioned Tables and Indexes.
SELECT * FROM sys.dm_db_incremental_stats_properties (object_id('PartitionTable'), 1);
For additional usage suggestions, see sys.dm_db_stats_properties.
See Also
DBCC SHOW_STATISTICS (Transact-SQL)
sys.stats (Transact-SQL)
Object Related Dynamic Management Views and Functions (Transact-SQL)
Dynamic Management Views and Functions (Transact-SQL)
sys.dm_db_stats_properties
sys.dm_db_stats_histogram (Transact-SQL)
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