On Wed, Sep 06, 2017 at 08:05:57PM +0200, R Smith wrote: > -- Another interesting thing to note: The INTERSECT test produces ORDERED > -- output, which suggests that an ORDER-BY addition to the query would > -- favour the INTERSECT method.
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Nothing about INTERSECT requires it to produce ordered output. Nothing about the JOIN case makes it not possible to produce ordered output by accident. You'll want to re-measure with an ORDER BY added. In any case, this is quite interesting. Many uses of JOIN are not merely to filter results, but to construct joined result rows -- such uses of JOIN cannot be optimized by using INTERSECT. But for filter-uses of JOIN... this might be a useful optimization for the engine to learn. Nico -- _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
