Wednesday, March 14, 2018

Fragmentation and Rebuild all index.

IF OBJECT_ID('tempdb..#work_to_do') IS NOT NULL
        DROP TABLE tempdb..#work_to_do

BEGIN TRY
--BEGIN TRAN

use [-----DBName---]

-- Ensure a USE  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 @pagecount INT;
    DECLARE @command NVARCHAR(4000);

    DECLARE @page_count_minimum SMALLINT
    SET @page_count_minimum = 50

    DECLARE @fragmentation_minimum FLOAT
    SET @fragmentation_minimum = 30.0

-- 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 ,
            page_count AS page_count
    INTO    #work_to_do
    FROM    sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL,
                                           'LIMITED')
    WHERE   avg_fragmentation_in_percent > @fragmentation_minimum
            AND index_id > 0
            AND page_count > @page_count_minimum;

IF CURSOR_STATUS('global', 'partitions') >= -1
BEGIN
 PRINT 'partitions CURSOR DELETED' ;
    CLOSE partitions
    DEALLOCATE partitions
END
-- Declare the cursor for the list of partitions to be processed.
    DECLARE partitions CURSOR LOCAL
    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, @pagecount;

            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;

            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 (@command); //uncomment for testing

            PRINT N'Rebuilding index ' + @indexname + ' on table '
                + @objectname;
            PRINT N'  Fragmentation: ' + CAST(@frag AS VARCHAR(15));
            PRINT N'  Page Count:    ' + CAST(@pagecount AS VARCHAR(15));
            PRINT N' ';
        END;

-- Close and deallocate the cursor.
    CLOSE partitions;
    DEALLOCATE partitions;

-- Drop the temporary table.
    DROP TABLE #work_to_do;
--COMMIT TRAN

END TRY
BEGIN CATCH
--ROLLBACK TRAN
    PRINT 'ERROR ENCOUNTERED:' + ERROR_MESSAGE()
END CATCH

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