SQL2008R2的索引重建

项目升级数据库由SQL2000升级到2008R2，今天对数据库表进行碎片扫描，发现有些表碎片较大，于是决定重建索引，联机帮助是最好的老师，将相关脚本摘录备后查。

参考sys.dm_db_index_physical_stats

• 检查索引碎片情况

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SELECT     OBJECT_NAME(object_id) as objectname,     object_id AS objectid,     index_id AS indexid,     partition_number AS partitionnum,     avg_fragmentation_in_percent AS fra FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, 'LIMITED') WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0;

• 使用脚本中的 sys.dm_db_index_physical_stats 重新生成或重新组织索引 （来源于联机帮助）

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SET NOCOUNT ON; DECLARE @objectid int; DECLARE @indexid int; DECLARE @partitioncount bigint; DECLARE @schemaname nvarchar(130); DECLARE @objectname nvarchar(130); DECLARE @indexname nvarchar(130); DECLARE @partitionnum bigint; DECLARE @partitions bigint; DECLARE @frag float; DECLARE @command nvarchar(4000); -- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function -- and convert object and index IDs to names. 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 (DB_ID(), 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. WHILE (1=1)     BEGIN;         FETCH NEXT            FROM partitions            INTO @objectid, @indexid, @partitionnum, @frag;         IF @@FETCH_STATUS < 0 BREAK;         SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(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 = QUOTENAME(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             SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REORGANIZE';         IF @frag >= 30.0             SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REBUILD';         IF @partitioncount > 1             SET @command = @command + N' PARTITION=' + CAST(@partitionnum AS nvarchar(10));         EXEC (@command);         PRINT N'Executed: ' + @command;     END;   -- Close and deallocate the cursor. CLOSE partitions; DEALLOCATE partitions;   -- Drop the temporary table. DROP TABLE #work_to_do; GO