Rebuild or reindex ?? good question !
Analysis indexes defragmentation RATIO and decide to REORGANIZE OR REBUILD
WHY ?
Rebuilding is massive time resource consuming, reindexing more fast than rebuild
Scope\purpose of this script di help to decide if rebuild ore reindex….
SOLUTION
RS Repacked Basic Script available time ago and free to use on MSDN: “SQL Script for SQL Index Maintenance (Degraf or Rebuild)”
HOW SYSTEM WORK ?
Example : Analysis indexes defragmentation RATIO < 30% *
“30” is an arbitrary decision point at which to SWITCH between REORGANIZING OR REBUILDING
AFTER DECISION: DO THAT !
IF @frag < 30.0
SET @command = N’ALTER INDEX ‘ + @indexname + N’ ON ‘ + @schemaname + N’.’ + @objectname + N’ REORGANIZE’; */
IF @frag >= 30.0
SET @command = N’ALTER INDEX ‘ + @indexname + N’ ON ‘ + @schemaname + N’.’ + @objectname + N’ REBUILD’; */
************************************************************************
/* RS REORGANIZE OR REBUILD SCRIPT 2.0
SP_DefragORRebuild2.0 */
USE [DATABASE]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE [dbo].[SP_DefragORRebuild2.0]
AS
BEGIN
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname nvarchar(130);
DECLARE @objectname nvarchar(130);
DECLARE @indexname nvarchar(130);
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command nvarchar(4000);
DECLARE @dbid smallint;
— ** READ FROM TABLES WITH Index degrafmentation stattistics
“sys.dm_db_index_physical_stats”
— ** convert object and index IDs to names.
SET @dbid = DB_ID();
SELECT
[object_id] AS objectid,
index_id AS indexid,
partition_number AS partitionnum,
avg_fragmentation_in_percent AS frag, page_count
/* Temporary table to calculate defragmentation RATIO > 10% , CASE > 10%*/
INTO #work_to_do
FROM sys.dm_db_index_physical_stats (@dbid, NULL, NULL , NULL, N’LIMITED’)
WHERE avg_fragmentation_in_percent > 10.0 — Allow limited fragmentation
AND index_id > 0 — Ignore heaps
AND page_count > 25; — Ignore small tables (not necessary to defragment\rebuild)
— Declare the cursor for the list of partitions to be processed.
DECLARE partitions CURSOR FOR SELECT objectid,indexid, partitionnum,frag FROM #work_to_do; //READ FROM #work_to_do
— Open the cursor.
OPEN partitions;
— Loop through the partitions.
WHILE (1=1)
BEGIN
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
IF @@FETCH_STATUS < 0 BREAK;
SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(s.name)
FROM sys.objects AS o JOIN sys.schemas as s ON s.schema_id = o.schema_id
WHERE o.object_id = @objectid;
SELECT @indexname = QUOTENAME(name)
FROM sys.indexes
WHERE object_id = @objectid AND index_id = @indexid;
SELECT @partitioncount = count (*)
FROM sys.partitions
WHERE object_id = @objectid AND index_id = @indexid;
/* Analysis indexes defragmentation RATIO < 30% o >=30% */
— 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding.
IF @frag < 30.0
SET @command = N’ALTER INDEX ‘ + @indexname + N’ ON ‘ + @schemaname + N’.’ + @objectname + N’ REORGANIZE’;
IF @frag >= 30.0
SET @command = N’ALTER INDEX ‘ + @indexname + N’ ON ‘ + @schemaname + N’.’ + @objectname + N’ REBUILD’;
IF @partitioncount > 1
SET @command = @command + N’ PARTITION=’ + CAST(@partitionnum AS nvarchar(10));
EXEC (@command);
PRINT N’Executed: ‘ + @command;
END
— Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;
— Drop the temporary table.
DROP TABLE #work_to_do;
END;
