Como defragmentar indices en GeneXus X.

Ahora que las bases de conocimiento no estan mas en ctree, no se puede correr un rebuild de los indices, como haciamos antes, sino que hay que hacerlo con SQL server.

Una forma facil de hacerlo (sacado de los Books Online de SQL Server 2005) es ejecutar el siguiente script, que lo que hace es defragmentar todos los índices que tengan una fragmentacion mayor al 30% (es la variable @maxfrag que se puede variar a gusto).


/*Perform a 'USE ' 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_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



Esto va a tener una salida similar a esta:


Executing DBCC INDEXDEFRAG (0, Entity,1) - fragmentation currently 97%
Pages Scanned Pages Moved Pages Removed
-------------------- -------------------- --------------------
28 22 3

DBCC execution completed. If DBCC printed error messages, contact your system administrator.
Executing DBCC INDEXDEFRAG (0, Entity,2) - fragmentation currently 97%
Pages Scanned Pages Moved Pages Removed
-------------------- -------------------- --------------------
32 15 10

DBCC execution completed. If DBCC printed error messages, contact your system administrator.
Executing DBCC INDEXDEFRAG (0, EntityVersion,1) - fragmentation currently 59%
Pages Scanned Pages Moved Pages Removed
-------------------- -------------------- --------------------
262 243 15

DBCC execution completed. If DBCC printed error messages, contact your system administrator.


que incluye las paginas leidas, movidas y borradas (Pages Scanned, moved, removed), por cada índice defragmentado.