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sys.dm_db_stats_properties (Transact-SQL)
Returns properties of statistics for the specified database object (table or indexed view) in the current SQL Server database.
Note
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The dynamic management object, sys.dm_db_stats_properties, is available in SQL Server 2012 starting with Service Pack 1 and in SQL Server 2008 R2 starting with Service Pack 2. |
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Column name |
Data type |
Description |
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object_id |
int |
ID of the object (table or indexed view) for which to return the properties of the statistics object. |
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stats_id |
int |
ID of the statistics object. Is unique within the table or indexed view. For more information, see sys.stats (Transact-SQL). |
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last_updated |
datetime2 |
Date and time the statistics object was last updated. |
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rows |
bigint |
Total number of rows in the table or indexed view 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. |
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rows_sampled |
bigint |
Total number of rows sampled for statistics calculations. |
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steps |
int |
Number of steps in the histogram. For more information, see DBCC SHOW_STATISTICS (Transact-SQL). |
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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. |
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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. |
sys.dm_db_stats_properties returns an empty rowset under any of the following conditions:
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object_id or stats_id is NULL.
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The specified object is not found or does not correspond to a table or indexed view.
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The specified statistics ID does not correspond to existing statistics for the specified object ID.
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The current user does not have permissions to view the statistics object.
This behavior allows for the safe usage of sys.dm_db_stats_properties when cross applied to rows in views such as sys.objects and sys.stats.
A. Returning all statistics properties for a table
The following example returns properties of all statistics that exist for the table TEST.
SELECT
sp.stats_id, name, filter_definition, last_updated, rows, rows_sampled, steps, unfiltered_rows, modification_counter
FROM sys.stats AS stat
CROSS APPLY sys.dm_db_stats_properties(stat.object_id, stat.stats_id) AS sp
WHERE stat.object_id = object_id('TEST');
SELECT
sp.stats_id, name, filter_definition, last_updated, rows, rows_sampled, steps, unfiltered_rows, modification_counter
FROM sys.stats AS stat
CROSS APPLY sys.dm_db_stats_properties(stat.object_id, stat.stats_id) AS sp
WHERE stat.object_id = object_id('TEST');
B. Returning statistics properties for frequently modified objects
The following example returns all tables, indexed views, and statistics in the current database for which the leading column was modified more than 1000 times since the last statistics update.
SELECT
obj.name, obj.object_id, stat.name, stat.stats_id, last_updated, modification_counter
FROM sys.objects AS obj
JOIN sys.stats stat ON stat.object_id = obj.object_id
CROSS APPLY sys.dm_db_stats_properties(stat.object_id, stat.stats_id) AS sp
WHERE modification_counter > 1000;
SELECT
obj.name, obj.object_id, stat.name, stat.stats_id, last_updated, modification_counter
FROM sys.objects AS obj
JOIN sys.stats stat ON stat.object_id = obj.object_id
CROSS APPLY sys.dm_db_stats_properties(stat.object_id, stat.stats_id) AS sp
WHERE modification_counter > 1000;
