SQL Server: 揭开隐藏数据的面纱,优化应用程序性能
2009-02-07 10:20:32 来源:WEB开发网Figure7Identifying Most-Used Indexes
-- Create required table structure only.
-- Note: this SQL must be the same as in the Database loop given in the -- following step.
SELECT TOP 1
[Usage] = (user_seeks + user_scans + user_lookups)
,DatabaseName = DB_NAME()
,TableName = OBJECT_NAME(s.[object_id])
,IndexName = i.name
INTO #TempUsage
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
WHERE s.database_id = DB_ID()
AND OBJECTPROPERTY(s.[object_id], 'IsMsShipped') = 0
AND (user_seeks + user_scans + user_lookups) > 0
-- Only report on active rows.
AND s.[object_id] = -999 -- Dummy value to get table structure.
;
-- Loop around all the databases on the server.
EXEC sp_MSForEachDB 'USE [?];
-- Table already exists.
INSERT INTO #TempUsage
SELECT TOP 10
[Usage] = (user_seeks + user_scans + user_lookups)
,DatabaseName = DB_NAME()
,TableName = OBJECT_NAME(s.[object_id])
,IndexName = i.name
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
WHERE s.database_id = DB_ID()
AND i.name IS NOT NULL -- Ignore HEAP indexes.
AND OBJECTPROPERTY(s.[object_id], ''IsMsShipped'') = 0
AND (user_seeks + user_scans + user_lookups) > 0 -- Only report on active rows.
ORDER BY [Usage] DESC
;
'
-- Select records.
SELECT TOP 10 * FROM #TempUsage ORDER BY [Usage] DESC
-- Tidy up.
DROP TABLE #TempUsage
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