December 30, 2008

To Defragment All Indexes In A Database

Simple Way To Defragment All Indexes In A Database that Is Fragmented Above A Declared Threshold.

-- Specify your Database Name
USE AdventureWorks;
GO
-- 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 CAST(TABLE_SCHEMA AS VARCHAR(100))
+'.'+CAST(TABLE_NAME AS VARCHAR(100)) AS 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, 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

No comments: