Hej

Alla index i SQL Server-databasen kommer att fragmenteras Efter att relaterade tabeller har fått många uppdateringar, radera transaktioner.

SQL Server Rebuild Index

Om indexet i tabellen är fragmenterat kommer alla transaktioner relaterade till den tabellen att vara mycket långsamma. Så SQL Server DBA bör ofta övervaka index och vilka index som är fragmenterade och vilka som inte är det.

SQL Server Reorganize Index

Du kan använda fragmenterat index med följande procedur. Denna procedur för att bygga om och omorganisera index beror på dess situation

CREATE PROC [INDEX_MAINTENANCE] @DBName VARCHAR(100)
AS BEGIN
            SET NOCOUNT ON;
            DECLARE
                  @OBJECT_ID INT,
                  @INDEX_NAME sysname,
                  @SCHEMA_NAME sysname,
                  @OBJECT_NAME sysname,
                  @AVG_FRAG float,
                  @command varchar(8000),
                  @RebuildCount int,
                  @ReOrganizeCount int
 
            CREATE TABLE #tempIM (
                  [ID] [INT] IDENTITY(1,1) NOT NULL PRIMARY KEY,
                  [INDEX_NAME] sysname NULL,
                  [OBJECT_ID] INT NULL,
                  [SCHEMA_NAME] sysname NULL,
                  [OBJECT_NAME] sysname NULL,
                  [AVG_FRAG] float
            )          
            SELECT @RebuildCount=0,@ReOrganizeCount=0
           
            --Get Fragentation values
            SELECT @command=
                  'Use ' + @DBName + ';
                  INSERT INTO #tempIM (OBJECT_ID, INDEX_NAME, SCHEMA_NAME, OBJECT_NAME, AVG_FRAG)
                  SELECT
                        ps.object_id,
                        i.name as IndexName,
                        OBJECT_SCHEMA_NAME(ps.object_id) as ObjectSchemaName,
                        OBJECT_NAME (ps.object_id) as ObjectName,
                        ps.avg_fragmentation_in_percent
                  FROM sys.dm_db_index_physical_stats (NULL, NULL, NULL , NULL, ''LIMITED'') ps
                  INNER JOIN sys.indexes i ON i.object_id=ps.object_id and i.index_id=ps.index_id
                  WHERE avg_fragmentation_in_percent > 5 AND ps.index_id > 0
                        and ps.database_id=DB_ID('''example@sqldat.com+''')
                  ORDER BY avg_fragmentation_in_percent desc
                  '
           
            exec(@command)
            DECLARE c CURSOR FAST_FORWARD FOR
                  SELECT OBJECT_ID,INDEX_NAME, SCHEMA_NAME, OBJECT_NAME, AVG_FRAG
                  FROM #tempIM
            OPEN c
            FETCH NEXT FROM c INTO @OBJECT_ID, @INDEX_NAME, @SCHEMA_NAME, @OBJECT_NAME, @AVG_FRAG
            WHILE @@FETCH_STATUS = 0
            BEGIN
                  --Reorganize or Rebuild
                  IF @AVG_FRAG>30 BEGIN
                        SELECT @command = 'Use ' + @DBName + '; ALTER INDEX [' + @INDEX_NAME +'] ON ['
                                                 + @SCHEMA_NAME + '].[' + @OBJECT_NAME + '] REBUILD   WITH (ONLINE = ON  )';
                        SET @RebuildCount = @RebuildCount+1
                  END ELSE BEGIN
                        SELECT @command = 'Use ' + @DBName + '; ALTER INDEX [' + @INDEX_NAME +'] ON ['
                                                 + @SCHEMA_NAME + '].[' + @OBJECT_NAME + '] REORGANIZE ';
                        SET @ReOrganizeCount = @ReOrganizeCount+1
                  END
                                                
                  BEGIN TRY
                        EXEC (@command); 
                  END TRY
                  BEGIN CATCH
                  END CATCH
                 
                  FETCH NEXT FROM c INTO @OBJECT_ID, @INDEX_NAME, @SCHEMA_NAME, @OBJECT_NAME, @AVG_FRAG
            END
            CLOSE c
            DEALLOCATE c
           
            DROP TABLE #tempIM
           
            SELECT cast(@RebuildCount as varchar(5))+' index Rebuild,'+cast(@ReOrganizeCount as varchar(5))+' index Reorganize is done.' as Result
END  

Du kan utföra denna procedur med följande fråga. Skriv databasnamn istället för DEVECI korrekt, så kommer proceduren att bygga om och omorganisera relaterade databasindex.

exec dbo.INDEX_MAINTENANCE 'DEVECI';