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在一个大型数据库中,数据的更改是非常频繁的。 而建立在这些数据上的索引也是需要经常去维护的。 否则这这些数据索引就起不到起应起的作用。甚至会成为数据库本身的负担。 我们就要定期的对数据库的索引进行维护 我在MSDN上发现了这个脚本不过其中有些小问题我已经修正 大家可以使用这个脚本对数据库的索引进行日常维护 复制代码 代码如下: SET NOCOUNT ON; DECLARE @objectid int; DECLARE @indexid int; DECLARE @partitioncount bigint; DECLARE @schemaname sysname; DECLARE @objectname sysname; DECLARE @indexname sysname; DECLARE @partitionnum bigint; DECLARE @partitions bigint; DECLARE @frag float; DECLARE @command varchar(8000); DECLARE @dbId int; -- ensure the temporary table does not exist IF EXISTS (SELECT name FROM sys.objects WHERE name = 'work_to_do') DROP TABLE work_to_do; -- conditionally select from the function, converting object and index IDs to names. set @dbId=DB_ID(); SELECT object_id AS objectid, index_id AS indexid, partition_number AS partitionnum, avg_fragmentation_in_percent AS frag INTO work_to_do FROM sys.dm_db_index_physical_stats (@dbId, NULL, NULL , NULL, 'LIMITED') WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0; -- Declare the cursor for the list of partitions to be processed. DECLARE partitions CURSOR FOR SELECT * FROM work_to_do; -- Open the cursor. OPEN partitions; -- Loop through the partitions. FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum, @frag; WHILE @@FETCH_STATUS = 0 BEGIN; SELECT @objectname = o.name, @schemaname = s.name FROM sys.objects AS o JOIN sys.schemas as s ON s.schema_id = o.schema_id WHERE o.object_id = @objectid; SELECT @indexname = name FROM sys.indexes WHERE object_id = @objectid AND index_id = @indexid; SELECT @partitioncount = count (*) FROM sys.partitions WHERE object_id = @objectid AND index_id = @indexid; -- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding IF @frag < 30.0 BEGIN; SELECT @command = 'ALTER INDEX [' + @indexname + '] ON ' + @schemaname + '.[' + @objectname + '] REORGANIZE'; IF @partitioncount > 1 SELECT @command = @command + ' PARTITION=' + CONVERT (CHAR, @partitionnum); EXEC (@command); END; IF @frag >= 30.0 BEGIN; SELECT @command = 'ALTER INDEX [' + @indexname +'] ON ' + @schemaname + '.[' + @objectname + '] REBUILD'; IF @partitioncount > 1 SELECT @command = @command + ' PARTITION=' + CONVERT (CHAR, @partitionnum); EXEC (@command); END; PRINT 'Executed ' + @command; FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum, @frag; END; -- Close and deallocate the cursor. CLOSE partitions; DEALLOCATE partitions; -- drop the temporary table IF EXISTS (SELECT name FROM sys.objects WHERE name = 'work_to_do') DROP TABLE work_to_do; GO 这个脚本在运行时 会建立一个表 work_to_do 整理完毕后会自动删除这个表。如果大家不喜欢这样的话也可以用 一个 临时表解决 . |
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