SqlServer性能优化用SQL(二)【索引监控】

SQL脚本:

-- 未被使用的索引SELECT  OBJECT_NAME(i.[object_id]) AS [Table Name] ,        i.nameFROM    sys.indexes AS i        INNER JOIN sys.objects AS o ON i.[object_id] = o.[object_id]WHERE   i.index_id NOT IN ( SELECT  ddius.index_id                            FROM    sys.dm_db_index_usage_stats AS ddius                            WHERE   ddius.[object_id] = i.[object_id]                                    AND i.index_id = ddius.index_id                                    AND database_id = DB_ID() )        AND o.[type] = 'U'ORDER BY OBJECT_NAME(i.[object_id]) ASC;--需要维护但是未被用过的索引SELECT  '[' + DB_NAME() + '].[' + su.[name] + '].[' + o.[name] + ']' AS [statement] ,        i.[name] AS [index_name] ,        ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] AS [user_reads] ,        ddius.[user_updates] AS [user_writes] ,        SUM(SP.rows) AS [total_rows]FROM    sys.dm_db_index_usage_stats ddius        INNER JOIN sys.indexes i ON ddius.[object_id] = i.[object_id]                                    AND i.[index_id] = ddius.[index_id]        INNER JOIN sys.partitions SP ON ddius.[object_id] = SP.[object_id]                                        AND SP.[index_id] = ddius.[index_id]        INNER JOIN sys.objects o ON ddius.[object_id] = o.[object_id]        INNER JOIN sys.sysusers su ON o.[schema_id] = su.[UID]WHERE   ddius.[database_id] = DB_ID() -- current database only        AND OBJECTPROPERTY(ddius.[object_id], 'IsUserTable') = 1        AND ddius.[index_id] > 0GROUP BY su.[name] ,        o.[name] ,        i.[name] ,        ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] ,        ddius.[user_updates]HAVING  ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] = 0ORDER BY ddius.[user_updates] DESC ,        su.[name] ,        o.[name] ,        i.[name]-- 可能不高效的非聚集索引 (writes > reads)SELECT  OBJECT_NAME(ddius.[object_id]) AS [Table Name] ,        i.name AS [Index Name] ,        i.index_id ,        user_updates AS [Total Writes] ,        user_seeks + user_scans + user_lookups AS [Total Reads] ,        user_updates - ( user_seeks + user_scans + user_lookups ) AS [Difference]FROM    sys.dm_db_index_usage_stats AS ddius WITH ( NOLOCK )        INNER JOIN sys.indexes AS i WITH ( NOLOCK ) ON ddius.[object_id] = i.[object_id]                                                       AND i.index_id = ddius.index_idWHERE   OBJECTPROPERTY(ddius.[object_id], 'IsUserTable') = 1        AND ddius.database_id = DB_ID()        AND user_updates > ( user_seeks + user_scans + user_lookups )        AND i.index_id > 1ORDER BY [Difference] DESC ,        [Total Writes] DESC ,        [Total Reads] ASC;--没有用于用户查询的索引SELECT  '[' + DB_NAME() + '].[' + su.[name] + '].[' + o.[name] + ']' AS [statement] ,        i.[name] AS [index_name] ,        ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] AS [user_reads] ,        ddius.[user_updates] AS [user_writes] ,        ddios.[leaf_insert_count] ,        ddios.[leaf_delete_count] ,        ddios.[leaf_update_count] ,        ddios.[nonleaf_insert_count] ,        ddios.[nonleaf_delete_count] ,        ddios.[nonleaf_update_count]FROM    sys.dm_db_index_usage_stats ddius        INNER JOIN sys.indexes i ON ddius.[object_id] = i.[object_id]                                    AND i.[index_id] = ddius.[index_id]        INNER JOIN sys.partitions SP ON ddius.[object_id] = SP.[object_id]                                        AND SP.[index_id] = ddius.[index_id]        INNER JOIN sys.objects o ON ddius.[object_id] = o.[object_id]        INNER JOIN sys.sysusers su ON o.[schema_id] = su.[UID]        INNER JOIN sys.[dm_db_index_operational_stats](DB_ID(), NULL, NULL,                                                       NULL) AS ddios ON ddius.[index_id] = ddios.[index_id]                                                              AND ddius.[object_id] = ddios.[object_id]                                                              AND SP.[partition_number] = ddios.[partition_number]                                                              AND ddius.[database_id] = ddios.[database_id]WHERE   OBJECTPROPERTY(ddius.[object_id], 'IsUserTable') = 1        AND ddius.[index_id] > 0        AND ddius.[user_seeks] + ddius.[user_scans] + ddius.[user_lookups] = 0ORDER BY ddius.[user_updates] DESC ,        su.[name] ,        o.[name] ,        i.[name]--查找丢失索引SELECT  user_seeks * avg_total_user_cost * ( avg_user_impact * 0.01 ) AS [index_advantage] ,        dbmigs.last_user_seek ,        dbmid.[statement] AS [Database.Schema.Table] ,        dbmid.equality_columns ,        dbmid.inequality_columns ,        dbmid.included_columns ,        dbmigs.unique_compiles ,        dbmigs.user_seeks ,        dbmigs.avg_total_user_cost ,        dbmigs.avg_user_impactFROM    sys.dm_db_missing_index_group_stats AS dbmigs WITH ( NOLOCK )        INNER JOIN sys.dm_db_missing_index_groups AS dbmig WITH ( NOLOCK ) ON dbmigs.group_handle = dbmig.index_group_handle        INNER JOIN sys.dm_db_missing_index_details AS dbmid WITH ( NOLOCK ) ON dbmig.index_handle = dbmid.index_handleWHERE   dbmid.[database_id] = DB_ID()ORDER BY index_advantage DESC;--索引上的碎片超过15%并且索引体积较大（超过500页）的索引。SELECT  '[' + DB_NAME() + '].[' + OBJECT_SCHEMA_NAME(ddips.[object_id],                                                     DB_ID()) + '].['        + OBJECT_NAME(ddips.[object_id], DB_ID()) + ']' AS [statement] ,        i.[name] AS [index_name] ,        ddips.[index_type_desc] ,        ddips.[partition_number] ,        ddips.[alloc_unit_type_desc] ,        ddips.[index_depth] ,        ddips.[index_level] ,        CAST(ddips.[avg_fragmentation_in_percent] AS SMALLINT) AS [avg_frag_%] ,        CAST(ddips.[avg_fragment_size_in_pages] AS SMALLINT) AS [avg_frag_size_in_pages] ,        ddips.[fragment_count] ,        ddips.[page_count]FROM    sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, 'limited') ddips        INNER JOIN sys.[indexes] i ON ddips.[object_id] = i.[object_id]                                      AND ddips.[index_id] = i.[index_id]WHERE   ddips.[avg_fragmentation_in_percent] > 15        AND ddips.[page_count] > 500ORDER BY ddips.[avg_fragmentation_in_percent] ,        OBJECT_NAME(ddips.[object_id], DB_ID()) ,        i.[name]--缺失索引SELECT migs.group_handle, mid.* FROM sys.dm_db_missing_index_group_stats AS migs INNER JOIN sys.dm_db_missing_index_groups AS mig ON (migs.group_handle = mig.index_group_handle) INNER JOIN sys.dm_db_missing_index_details AS mid ON (mig.index_handle = mid.index_handle) WHERE migs.group_handle = 2--无用索引SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED SELECT DB_NAME() AS DatbaseName , SCHEMA_NAME(O.Schema_ID) AS SchemaName , OBJECT_NAME(I.object_id) AS TableName , I.name AS IndexName INTO #TempNeverUsedIndexes FROM sys.indexes I INNER JOIN sys.objects O ON I.object_id = O.object_id WHERE 1=2 EXEC sp_MSForEachDB 'USE [?]; INSERT INTO #TempNeverUsedIndexes SELECT DB_NAME() AS DatbaseName , SCHEMA_NAME(O.Schema_ID) AS SchemaName , OBJECT_NAME(I.object_id) AS TableName , I.NAME AS IndexName FROM sys.indexes I INNER JOIN sys.objects O ON I.object_id = O.object_id LEFT OUTER JOIN sys.dm_db_index_usage_stats S ON S.object_id = I.object_id AND I.index_id = S.index_id AND DATABASE_ID = DB_ID() WHERE OBJECTPROPERTY(O.object_id,''IsMsShipped'') = 0 AND I.name IS NOT NULL AND S.object_id IS NULL' SELECT * FROM #TempNeverUsedIndexes ORDER BY DatbaseName, SchemaName, TableName, IndexName DROP TABLE #TempNeverUsedIndexes--经常被大量更新，但是却基本不适用的索引项-SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED SELECT DB_NAME() AS DatabaseName , SCHEMA_NAME(o.Schema_ID) AS SchemaName , OBJECT_NAME(s.[object_id]) AS TableName , i.name AS IndexName , s.user_updates , s.system_seeks + s.system_scans + s.system_lookups AS [System usage] INTO #TempUnusedIndexes FROM sys.dm_db_index_usage_stats s INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id] AND s.index_id = i.index_id INNER JOIN sys.objects o ON i.object_id = O.object_id WHERE 1=2 EXEC sp_MSForEachDB 'USE [?]; INSERT INTO #TempUnusedIndexes SELECT TOP 20 DB_NAME() AS DatabaseName , SCHEMA_NAME(o.Schema_ID) AS SchemaName , OBJECT_NAME(s.[object_id]) AS TableName , i.name AS IndexName , s.user_updates , s.system_seeks + s.system_scans + s.system_lookups AS [System usage] FROM sys.dm_db_index_usage_stats s INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id] AND s.index_id = i.index_id INNER JOIN sys.objects o ON i.object_id = O.object_id WHERE s.database_id = DB_ID() AND OBJECTPROPERTY(s.[object_id], ''IsMsShipped'') = 0 AND s.user_seeks = 0 AND s.user_scans = 0 AND s.user_lookups = 0 AND i.name IS NOT NULL ORDER BY s.user_updates DESC' SELECT TOP 20 * FROM #TempUnusedIndexes ORDER BY [user_updates] DESC DROP TABLE #TempUnusedIndexes