--判断无用的索引: SELECT TOP 30 DB_NAME() AS DatabaseName , ‘[‘ + SCHEMA_NAME(o.Schema_ID) + ‘]‘ + ‘.‘ + ‘[‘ + OBJECT_NAME(s.[object_id]) + ‘]‘ AS TableName , i.name AS IndexName , i.type AS IndexType , 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 ; ---判断哪些索引缺失: SELECT TOP 30 ROUND(s.avg_total_user_cost * s.avg_user_impact * ( s.user_seeks + s.user_scans ), 0) AS [Total Cost] , s.avg_total_user_cost * ( s.avg_user_impact / 100.0 ) * ( s.user_seeks + s.user_scans ) AS Improvement_Measure , DB_NAME() AS DatabaseName , d.[statement] AS [Table Name] , equality_columns , inequality_columns , included_columns FROM sys.dm_db_missing_index_groups g INNER JOIN sys.dm_db_missing_index_group_stats s ON s.group_handle = g.index_group_handle INNER JOIN sys.dm_db_missing_index_details d ON d.index_handle = g.index_handle WHERE s.avg_total_user_cost * ( s.avg_user_impact / 100.0 ) * ( s.user_seeks + s.user_scans ) > 10 ORDER BY [Total Cost] DESC , s.avg_total_user_cost * s.avg_user_impact * ( s.user_seeks + s.user_scans ) DESC ---看看那些索引维护成本很高 通俗的说就是更新次数大于使用这个索引的次数 SELECT TOP 20 DB_NAME() AS DatabaseName , ‘[‘ + SCHEMA_NAME(o.Schema_ID) + ‘]‘ + ‘.‘ + ‘[‘ + OBJECT_NAME(s.[object_id]) + ‘]‘ AS TableName , i.name AS IndexName , i.type AS IndexType , ( s.user_updates ) AS update_usage , ( s.user_seeks + s.user_scans + s.user_lookups ) AS retrieval_usage , ( s.user_updates ) - ( s.user_seeks + user_scans + s.user_lookups ) AS maintenance_cost , s.system_seeks + s.system_scans + s.system_lookups AS system_usage , s.last_user_seek , s.last_user_scan , s.last_user_lookup 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(‘{0}‘) AND i.name IS NOT NULL AND OBJECTPROPERTY(s.[object_id], ‘IsMsShipped‘) = 0 AND ( s.user_seeks + s.user_scans + s.user_lookups ) > 0 ORDER BY maintenance_cost DESC; ----常常使用的索引查看 看看你常用使用的索引是否建立的合理 SELECT TOP 20 DB_NAME() AS DatabaseName , ‘[‘+SCHEMA_NAME(o.Schema_ID)+‘]‘+‘.‘+‘[‘+OBJECT_NAME(s.[object_id]) +‘]‘AS TableName , i.name AS IndexName , i.type as IndexType , (s.user_seeks + s.user_scans + s.user_lookups) AS Usage , s.user_updates 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 i.name IS NOT NULL AND OBJECTPROPERTY(s.[object_id], ‘IsMsShipped‘) = 0 ORDER BY Usage DESC
时间: 2024-10-12 11:49:42