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這篇文章主要介紹“SQL Server 索引維護的 sql 語句”,在日常操作中,相信很多人在 SQL Server 索引維護的 sql 語句問題上存在疑惑,丸趣 TV 小編查閱了各式資料,整理出簡單好用的操作方法,希望對大家解答”SQL Server 索引維護的 sql 語句”的疑惑有所幫助!接下來,請跟著丸趣 TV 小編一起來學習吧!
使用以下腳本查看數據庫索引碎片的大小情況:
復制代碼 代碼如下:
DBCC SHOWCONTIG WITH FAST, TABLERESULTS, ALL_INDEXES, NO_INFOMSGS
以下使用腳本來處理維護作業:
復制代碼 代碼如下:
/*Perform a USE database name to select the database in which to run the script.*/ -- Declare variables SET NOCOUNT ON; DECLARE @tablename varchar(255); DECLARE @execstr varchar(400); DECLARE @objectid int; Declare @IndexName varchar(500); DECLARE @indexid int; DECLARE @frag decimal; DECLARE @maxfrag decimal; DECLARE @TmpName varchar(500); -- Declare @TmpName = set @TmpName = -- Decide on the maximum fragmentation to allow for. SELECT @maxfrag = 30.0; -- Declare a cursor. DECLARE tables CURSOR FOR SELECT TABLE_SCHEMA + . + TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = BASE TABLE -- Create the table. CREATE TABLE #fraglist ( ObjectName char(255), ObjectId int, IndexName char(255), IndexId int, Lvl int, CountPages int, CountRows int, MinRecSize int, MaxRecSize int, AvgRecSize int, ForRecCount int, Extents int, ExtentSwitches int, AvgFreeBytes int, AvgPageDensity int, ScanDensity decimal, BestCount int, ActualCount int, LogicalFrag decimal, ExtentFrag decimal); -- Open the cursor. OPEN tables; -- Loop through all the tables in the database. FETCH NEXT FROM tables INTO @tablename; WHILE @@FETCH_STATUS = 0 BEGIN; -- Do the showcontig of all indexes of the table INSERT INTO #fraglist EXEC (DBCC SHOWCONTIG ( + @tablename + ) WITH FAST, TABLERESULTS, ALL_INDEXES, NO_INFOMSGS FETCH NEXT FROM tables INTO @tablename; END; -- Close and deallocate the cursor. CLOSE tables; DEALLOCATE tables; -- Declare the cursor for the list of indexes to be defragged. DECLARE indexes CURSOR FOR SELECT ObjectName, ObjectId,IndexName,IndexId, LogicalFrag FROM #fraglist WHERE INDEXPROPERTY (ObjectId, IndexName, IndexDepth) 0; -- Open the cursor. OPEN indexes; -- Loop through the indexes. FETCH NEXT FROM indexes INTO @tablename, @objectid, @IndexName,@indexid, @frag; WHILE @@FETCH_STATUS = 0 BEGIN; if @frag @maxfrag Begin SELECT @execstr = ALTER INDEX [ + RTRIM(@IndexName) + ] ON [ + RTRIM(@tablename) + ] REORGANIZE WITH ( LOB_COMPACTION = ON ) print @maxfrag + + @execstr End else Begin SELECT @execstr = ALTER INDEX [ + RTRIM(@IndexName) + ] ON [ + RTRIM(@tablename) + ] REBUILD WITH ( PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, SORT_IN_TEMPDB = OFF, ONLINE = OFF ) print @maxfrag + + @execstr End EXEC (@execstr); -- 更新統計信息 IF @TmpName @tablename BEGIN SET @tmpName=@tableName PRINT UPDATE STATISTICS +@TableName + WITH FULLSCAN EXEC (UPDATE STATISTICS +@TableName + WITH FULLSCAN ) END FETCH NEXT FROM indexes INTO @tablename, @objectid, @IndexName,@indexid, @frag; END; -- Close and deallocate the cursor. CLOSE indexes; DEALLOCATE indexes; -- Delete the temporary table. DROP TABLE #fraglist;
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