(2014/04/10 0:08), Tom Lane wrote: > Kyotaro HORIGUCHI <horiguchi.kyot...@lab.ntt.co.jp> writes: >> Oops! I found a bug in this patch. The previous v8 patch missed >> the case that build_index_pathkeys() could build a partial >> pathkeys from the index tlist. > > TBH I think that's barely the tip of the iceberg of cases where this > patch will get the wrong answer.
> Also, I don't see it doing anything to check the ordering > of multiple index columns I think that the following code in index_pathkeys_are_extensible() would check the ordering: + if (!pathkeys_contained_in(pathkeys, root->query_pathkeys)) + return false; > Also, what's with the success return > before the loop: > > + if (list_length(pathkeys) == list_length(root->query_pathkeys)) > + return true; > > At this point you haven't proven *anything at all* about whether the > index columns have something to do with the query_pathkeys. I think that the two pathkeys would be proved to be equal, if the both conditions are satisfied. Thanks, Best regards, Etsuro Fujita -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers