Rebuild and Reorganize Indexing Sql Server Scripts

Hello Folks, today I will explain regarding when and why we should Rebuild or Reorganize Index in Sql Server regularly.

There is a simple rule behind Rebuild and Reorganize indexes which is shown in MSDN as below:

 

See as per MSDN when avg_fragmentation_in_percent’s value is in between 5 % to 30%, we have to do reorganize indexing, but when its more than 30% we should do Rebuild Index with (ONLINE = ON).

Below is the standard script for Rebuilding and Reorganizing Indexes:

-- Make Sure you have write USE <databasename> statement before executing statement.  
-- USE <databasename>
SET NOCOUNT ON;  
DECLARE @objectid int;  
DECLARE @indexid int;  
DECLARE @partitioncount bigint;  
DECLARE @schemaname nvarchar(500);   
DECLARE @objectname nvarchar(500);   
DECLARE @indexname nvarchar(500);   
DECLARE @partitionnum bigint;  
DECLARE @partitions bigint;  
DECLARE @frag float;  
DECLARE @command nvarchar(4000);   
-- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function   
-- and convert object and index IDs to names.  
SELECT  
    object_id AS objectid,  
    index_id AS indexid,  
    partition_number AS partitionnum,  
    avg_fragmentation_in_percent AS frag  
INTO #work_to_do  
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, 'LIMITED')  
WHERE index_id > 0;  

-- Declare the cursor for the list of partitions to be processed.  
DECLARE partitions CURSOR FOR SELECT * 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;  

		-- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding.  
        IF @frag < 30.0  OR @frag >= 5.0
            SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REORGANIZE';  
        IF @frag >= 30.0 --OR @frag < 5.0 
            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;  
GO  

You can also download Rebuild and Reorganize Indexing Sql Server Script.