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SQL SERVER 2008 R2 重建索引的方法
类别:mssql2008   作者:码皇   来源:互联网   点击:

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,MSDN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

    1.SELECT2.OBJECT_NAME(object_id) as objectname,3.object_id AS objectid,4.index_id AS indexid,5.partition_number AS partitionnum,6.avg_fragmentation_in_percent AS fra7.FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, ‘LIMITED')8.WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0;
    9. 10.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)11. 12.SET NOCOUNT ON;
    13.DECLARE @objectid int;
    14.DECLARE @indexid int;
    15.DECLARE @partitioncount bigint;
    16.DECLARE @schemaname nvarchar(130);
    17.DECLARE @objectname nvarchar(130);
    18.DECLARE @indexname nvarchar(130);
    19.DECLARE @partitionnum bigint;
    20.DECLARE @partitions bigint;
    21.DECLARE @frag float;
    22.DECLARE @command nvarchar(4000);
    23.– Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function24.– and convert object and index IDs to names.25.SELECT26.object_id AS objectid,27.index_id AS indexid,28.partition_number AS partitionnum,29.avg_fragmentation_in_percent AS frag30.INTO #work_to_do31.FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, ‘LIMITED')32.WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0;
    33.– Declare the cursor for the list of partitions to be processed.34.DECLARE partitions CURSOR FOR SELECT * FROM #work_to_do;
    35.– Open the cursor.36.OPEN partitions;
    37.– Loop through the partitions.38.WHILE (1=1)39.BEGIN;
    40.FETCH NEXT41.FROM partitions42.INTO @objectid, @indexid, @partitionnum, @frag;
    43.IF @@FETCH_STATUS < 0 BREAK;
    44.SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(s.name)45.FROM sys.objects AS o46.JOIN sys.schemas as s ON s.schema_id = o.schema_id47.WHERE o.object_id = @objectid;
    48.SELECT @indexname = QUOTENAME(name)49.FROM sys.indexes50.WHERE object_id = @objectid AND index_id = @indexid;
    51.SELECT @partitioncount = count (*)52.FROM sys.partitions53.WHERE object_id = @objectid AND index_id = @indexid;
    54.– 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding.55.IF @frag < 30.056.SET @command = N‘ALTER INDEX ‘ + @indexname + N‘ ON ‘ + @schemaname + N‘.' + @objectname + N‘ REORGANIZE';
    57.IF @frag >= 30.058.SET @command = N‘ALTER INDEX ‘ + @indexname + N‘ ON ‘ + @schemaname + N‘.' + @objectname + N‘ REBUILD';
    59.IF @partitioncount > 160.SET @command = @command + N‘ PARTITION=' + CAST(@partitionnum AS nvarchar(10));
    61.EXEC (@command);
    62.PRINT N‘Executed: ‘ + @command;
    63.END;
    64.– Close and deallocate the cursor.65.CLOSE partitions;
    66.DEALLOCATE partitions;
    67.– Drop the temporary table.68.DROP TABLE #work_to_do;
    69.GO
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