On Sat, Sep 25, 2010 at 3:05 PM, Max Vlasov <[email protected]> wrote:
> > Thanks, Richard, this is a perfect explanation and now it makes sense to > me. > > As for left joins, I suppose that the optimizer choses other approach for > them since it has a bias in estimating the sizes of tables when the left > join was used. As common sense tells me, left joins usually used with big > tables looking for lookups in little tables. So in this case other approach > would have better estimate in performance. Is this true? I'm asking because > replacing inner with left would be used as an alternative in cases like > this > in the future. > LEFT JOIN is not commutative. Hence the option of moving table B to the outer loop is not allowed. > > Max > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- D. Richard Hipp [email protected] _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
