SQL Server 索引维护

使用以下脚本查看数据库索引碎片的大小情况：

 DBCC SHOWCONTIG  WITH FAST, TABLERESULTS, ALL_INDEXES, NO_INFOMSGS

 

 

以下使用脚本来处理维护作业：

 

/*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);
    
    --更新统计信息
      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;
GO