[Maria-developers] request for a feature -- LIMIT_ROWS_EXAMINED
I want a variant of the LIMIT clause that limits the number of rows examined during SELECT processing. This should return OK when the limit is reached -- something like NESTED_LOOP_QUERY_LIMIT. While LIMIT can be LIMIT x and LIMIT x,y. This only supports one argument -- LIMIT_ROWS_EXAMINED x. Are you interested in implementing this feature for me? We will sponsor the work. The purpose of the feature is to prevent queries from taking too long when there isn't a great index and many rows might be filtered. -- Mark Callaghan mdcallag@gmail.com
Hi!
"MARK" == MARK CALLAGHAN <mdcallag@gmail.com> writes:
MARK> I want a variant of the LIMIT clause that limits the number of rows MARK> examined during SELECT processing. This should return OK when the MARK> limit is reached -- something like NESTED_LOOP_QUERY_LIMIT. While MARK> LIMIT can be LIMIT x and LIMIT x,y. This only supports one argument -- MARK> LIMIT_ROWS_EXAMINED x. Are you interested in implementing this feature MARK> for me? We will sponsor the work. The purpose of the feature is to MARK> prevent queries from taking too long when there isn't a great index MARK> and many rows might be filtered. I am a bit afraid of returning 'ok'. Would it not be better to return an error? Another option would be to generate a warning so that the application can know that they didn't get all rows. We can do this and it should be relatively easy to do. Regards, Monty
participants (2)
-
MARK CALLAGHAN -
Michael Widenius