USE pubs
DBCC SHOWCONTIG WITH TABLERESULTS, ALL_INDEXES
E. 使用 DBCC SHOWCONTIG 和 DBCC INDEXDEFRAG 对数据库中的索引进行碎片整理
下例显示对数据库中碎片数量在声明的阈值之上的所有索引进行碎片整理的简单方法。
/*Perform a 'USE <database name>' to select the database in which to run the script.*/
-- Declare variables
SET NOCOUNT ON
DECLARE @tablename VARCHAR (128)
DECLARE @execstr VARCHAR (255)
DECLARE @objectid INT
DECLARE @indexid INT
DECLARE @frag DECIMAL
DECLARE @maxfrag DECIMAL
-- Decide on the maximum fragmentation to allow
SELECT @maxfrag = 30.0
-- Declare cursor
DECLARE tables CURSOR FOR
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
-- 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 cursor for list of indexes to be defragged
DECLARE indexes CURSOR FOR
SELECT ObjectName, ObjectId, IndexId, LogicalFrag
FROM #fraglist
WHERE LogicalFrag >= @maxfrag
AND INDEXPROPERTY (ObjectId, IndexName, 'IndexDepth') > 0
-- Open the cursor
OPEN indexes
-- loop through the indexes
FETCH NEXT
FROM indexes
INTO @tablename, @objectid, @indexid, @frag