Is there any optimisation done for the case of a symmetric EXCEPT, to avoid performing duplicate SELECT statements? E.g.:
(SELECT A... EXCEPT SELECT B...) UNION (SELECT B... EXCEPT SELECT A...) would seem to be a poor approach to getting the set of rows in either A or B. Are there potentially better generic approaches, or other tricks I've missed? (At the moment I have a query that does not use EXCEPT but is instead tied to the particulars of my schema/data, which is fine. I'm just curious about the more general case.) Jamie _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
