Fastest Way to Delete a large number of data

Question

I m trying to delete a large number of Data
this Proc will be running every day without disturbing the other Process
SET sql = 'DELETE TOP (100) FROM ' + @TableName + ' WHERE Id IN (Select Distinct Id FROM [state] WHERE ToDel = 1)'SET @Deleted_Rows = 1;SET @Rows = 0; WHILE (@Deleted_Rows > 0)BEGIN BEGIN TRANEXEC sp_executesql @sql SET @Deleted_Rows = (SELECT @@ROWCOUNT);SET @Rows = (@Rows + @Deleted_Rows);COMMIT TRANWaitFor DELAY '00:00:00:01' END
Have you any Idea how can I optimize my Query ?
Thank you very much

Answer 1

Hi, following are few thoughts.
1. If you can manage without dynamic sql then it may yield better performance as except table name there is no need for it as per your query.
2. Ensure indexes are in place.
3. If the table in question is not participant in replication then you may slightly go for higher batch size and again it depends on volume.
Please take a look at the tweaked code.
declare @Deleted_Rows int, @Rows int;
SET @Deleted_Rows = 1;
SET @Rows = 0;
WHILE (@Deleted_Rows > 0)
BEGIN
BEGIN TRAN;
DELETE TOP (100) t1
FROM
tabName as t1
WHERE exists (Select * FROM [state] as t2 WHERE t2.ToDel = 1 and t2.Id = t1.id);
SET @Deleted_Rows = @@ROWCOUNT ;
SET @Rows = @Rows + @Deleted_Rows;
COMMIT TRAN;
WaitFor DELAY '00:00:00:01';
END
Print 'Total rows deleted : '+convert(varchar(50), @Rows);