A warning would be excellent. An error would be a problem. Returning OK is probably not the best result when the examined limit is reached.
On Wed, Dec 21, 2011 at 7:17 AM, Timour Katchaounov <[email protected]> wrote: >> >> Hi! >> >>>>>>> "MARK" == MARK CALLAGHAN<[email protected]> 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. > > > This is what I would prefer to do: > - process the new LIMIT_ROWS_EXAMINED clause in the same way as LIMIT, > just with a different condition to end query execution, > - in addition produce a warning that not all rows were returned. > > Mark, does the above suit you? If you don't want to check for > warnings, you can skip them, however users will have the option > to detect that not all rows were returned. > > Timour > >> >> We can do this and it should be relatively easy to do. >> >> Regards, >> Monty >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~maria-developers >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~maria-developers >> More help : https://help.launchpad.net/ListHelp -- Mark Callaghan [email protected] _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
