内容摘要:本文以笔者在实际工作中对SQL Server数据库中索引维护的思路和方法为导向,为大家介绍SQL Server索引维护相关的知识和方法。
针对Sql Server2000的联机维护:
/*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 for.
SELECT @maxfrag = 30.0;
-- Declare a cursor.
DECLARE tables CURSOR FOR
SELECT TABLE_SCHEMA+'.'+TABLE_NAME --MSDN上面直接使用TABLE_NAME,如果SCHEMA不是DBO就会出错
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, 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;
WHILE @@FETCH_STATUS = 0
BEGIN
PRINT 'Executing DBCC INDEXDEFRAG (0, ' + RTRIM(@tablename) + ',
' + RTRIM(@indexid) + ') - fragmentation currently '
+ RTRIM(CONVERT(varchar(15),@frag)) + '%';
SELECT @execstr = 'DBCC INDEXDEFRAG (0, ' + RTRIM(@objectid) + ',
' + RTRIM(@indexid) + ')';
EXEC (@execstr);
FETCH NEXT
FROM indexes
INTO @tablename, @objectid, @indexid, @frag;
END;
-- Close and deallocate the cursor.
CLOSE indexes;
DEALLOCATE indexes;
-- Delete the temporary table.
DROP TABLE #fraglist;
GO
针对SQL Server 2000的脱机维护:
来源:IT专家网 作者:王红波 责编:豆豆技术应用