Does PostgreSQL use the COMMUTATOR property of an operator to determine if flip-flopped arguments can be collapsed. I used to think it did until someone pointed it doesn't - For example in the below SELECT b.* FROM boszip b INNER JOIN landparcels l ON (b.the_geom && l.the_geom AND l.the_geom && b.the_geom AND l.the_geom && b.the_geom ) WHERE l.gid = b.gid and b.gid = l.gid limit 1 If I look at the query plan - I see the plan has reduced things down to l.gid = b.gid AND (b.the_geom && l.the_geom AND l.the_geom && b.the_geom) Why is (b.the_geom && l.the_geom AND l.the_geom && b.the_geom) not reduced down to just b.the_geom && l.the_geom even though && is defined as the commutator of &&? Thanks, Regina
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