Script to appropriate rebuild/reorganize database indexes – SQL Server 2005


Depending on fragmentation index level appropriated action will be taken (no action, rebuild or reorganize)

If average fragmentation is less than 10% no action will be taken, if average fragmentation is between 10% and 30% index will be reorganized, finally if index average fragmentation is greater than 30% index will be rebuilt.

-- Ensure a USE <databasename> statement has been executed first.

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;

-- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function

-- and 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

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

-- Declare the cursor for the list of partitions to be processed.

DECLARE partitions CURSOR FOR SELECT objectid,indexid, partitionnum,frag 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

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;

GO

If average fragmentation is less than 10% no action will be taken, if average fragmentation is between 10% and 30% index will be reorganized, finally if index average fragmentation is greater than 30% index will be rebuilt.

Want a full complete solution (also a bit more complex) solution? Please check this great article provided by Ola Hallengren available at:

http://ola.hallengren.com

Documentation

http://ola.hallengren.com/sql-server-index-and-statistics-maintenance.html

T-SQL script

http://ola.hallengren.com/scripts/MaintenanceSolution.sql

Comments (9)

  1. Jamie Valentine says:

    Thank you for sharing this – I was looking for something dynamic to incorporate in our business.  I'm new to T-SQL and these scripts that you share are incredibly helpful!  I appreciate your sharing of knowledge….  

    Thanks Again!

  2. Davin says:

    Shouldn't you also update the statistics if you reorganize the index?

  3. Jwalanth says:

    Shouldn't you also update the statistics if you reorganize the index?

    yes you need to , a reorganize does not update teh statistics.

  4. Manu says:

    "avg_fragmentation_in_percent" doesnt comes to Normal even after doing this.

    Do you have any idea to Reduce it .

  5. Danny says:

    Excellent!  Thanks for you detailed script.  

  6. Paul Lee says:

    What does it means

    cannot be reorganized because page level locking is disabled.

  7. R K Kothapalli says:

    Very useful. Thanks for the absolute script.

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