SQL Server – Identify Unused Tables

sql-server-2017table

I have a database that has 225 tables in it

What is the best way to find out / log which tables are used, and which are not ?

I would like to see something similar to below:

Table 1 - select 2222 times, insert 0 times, update 3 times, delete 0 times  
Table 2 - select 1 times, insert 50 times, update 0 times, delete 5 times

Or in a below format:

Table 1 - select 2222  
Table 1 - update 0  
Table 2 - select 1  
Table 2 - insert 50  
Table 2 - delete 5

Best Answer

    SELECT t.name AS [TableName],
       fi.page_count AS [Pages],
       fi.record_count AS [Rows],
       CAST(fi.avg_record_size_in_bytes AS int) AS [AverageRecordBytes],
       CAST(fi.avg_fragmentation_in_percent AS int) AS [AverageFragmentationPercent],
       SUM(iop.leaf_insert_count) AS [Inserts],
       SUM(iop.leaf_delete_count) AS [Deletes],
       SUM(iop.leaf_update_count) AS [Updates],
       SUM(iop.row_lock_count) AS [RowLocks],
       SUM(iop.page_lock_count) AS [PageLocks]
  FROM sys.dm_db_index_operational_stats(DB_ID(),NULL,NULL,NULL) AS iop
  JOIN sys.indexes AS i ON iop.index_id = i.index_id AND
                           iop.object_id = i.object_id
  JOIN sys.tables AS t ON i.object_id = t.object_id AND
                          i.type_desc IN ('CLUSTERED', 'HEAP')
  JOIN sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, 'SAMPLED') AS fi ON fi.object_id=CAST(t.object_id AS int) AND
                                                                                     fi.index_id=CAST(i.index_id AS int)
  GROUP BY t.name, fi.page_count, fi.record_count, fi.avg_record_size_in_bytes, fi.avg_fragmentation_in_percent
  ORDER BY [RowLocks] desc

Remarks: sys.dm_db_index_operational_stats

(How the Counters in the Metadata Cache Are Reset

The data returned by sys.dm_db_index_operational_stats exists only as long as the metadata cache object that represents the heap or index is available. This data is neither persistent nor transactionally consistent. This means you cannot use these counters to determine whether an index has been used or not, or when the index was last used. For information about this, see sys.dm_db_index_usage_stats.

The values for each column are set to zero whenever the metadata for the heap or index is brought into the metadata cache and statistics are accumulated until the cache object is removed from the metadata cache. Therefore, an active heap or index will likely always have its metadata in the cache, and the cumulative counts may reflect activity since the instance of SQL Server was last started. The metadata for a less active heap or index will move in and out of the cache as it is used. As a result, it may or may not have values available. Dropping an index will cause the corresponding statistics to be removed from memory and no longer be reported by the function. Other DDL operations against the index may cause the value of the statistics to be reset to zero.)

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