怎样检查fragmentation

可以运行下面SQL语句：

SELECT dbschemas.[name] AS 'Schema',  dbtables.[name] AS 'Table',  dbindexes.[name] AS 'Index', indexstats.index_type_desc, indexstats.avg_fragmentation_in_percent, indexstats.page_countFROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL, NULL, NULL) AS indexstatsINNER JOIN sys.tables dbtables ON (dbtables.[object_id] = indexstats.[object_id])INNER JOIN sys.schemas dbschemas ON (dbtables.[schema_id] = dbschemas.[schema_id])INNER JOIN sys.indexes AS dbindexes ON (dbindexes.[object_id] = indexstats.[object_id]AND indexstats.index_id = dbindexes.index_id)WHERE indexstats.database_id = DB_ID()ORDER BY indexstats.avg_fragmentation_in_percent DESC

参考运行后这个avg_fragmentation_in_percent值，肯定是越小越好：

以下内容于2014-10-07 13:15分更新：Insus.NET 写了一个存储过程，把avg_fragmentation_in_percent值大于或等于30的，rebuild索引：

CREATE PROCEDURE [dbo].[usp_RebuildIndex]ASBEGIN    IF OBJECT_ID('#t') IS NOT NULL        DROP TABLE #t    CREATE TABLE #t    (    [ID] INT IDENTITY(1,1) PRIMARY KEY NOT NULL,    [Table] NVARCHAR(128) NOT NULL,    [Index] NVARCHAR(128) NOT NULL    )    INSERT INTO #t ([Table],[Index]) SELECT  dbtables.[name],dbindexes.[name]     FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL, NULL, NULL) AS indexstats    INNER JOIN sys.tables dbtables ON (dbtables.[object_id] = indexstats.[object_id])    INNER JOIN sys.schemas dbschemas ON (dbtables.[schema_id] = dbschemas.[schema_id])    INNER JOIN sys.indexes AS dbindexes ON (dbindexes.[object_id] = indexstats.[object_id]    AND indexstats.index_id = dbindexes.index_id)    WHERE indexstats.database_id = DB_ID() AND dbindexes.[name] IS NOT NULL AND indexstats.avg_fragmentation_in_percent >=　30    DECLARE @r INT = 1, @rs INT = 0    SELECT @rs = MAX([ID]) FROM #t    WHILE @r <= @rs    BEGIN        DECLARE @table NVARCHAR(128), @index NVARCHAR(128)        SELECT @table = [Table],@index = [Index] FROM #t WHERE [ID] = @r        EXECUTE('ALTER INDEX '+@index +' ON '+ @table +' REBUILD;')        SET @r = @r + 1    ENDENDGO