From: Tom Lane Date: Tue, 24 May 2005 18:03:24 +0000 (+0000) Subject: Previous fix for "x FULL JOIN y ON true" failed to handle the case X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=90b20b237fb397a41fe5eed655400a61fa4d3e8c;p=users%2Fbernd%2Fpostgres.git Previous fix for "x FULL JOIN y ON true" failed to handle the case where there was also a WHERE-clause restriction that applied to the join. The check on restrictlist == NIL is really unnecessary anyway, because select_mergejoin_clauses already checked for and complained about any unmergejoinable join clauses. So just take it out. --- diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c index a79d3e0e3e..1954e86af4 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -498,15 +498,10 @@ match_unsorted_outer(Query *root, * nestloop path, but since mergejoin is our only join type that * supports FULL JOIN, it's necessary to generate a clauseless * mergejoin path instead. - * - * Unfortunately this can't easily be extended to handle the case - * where there are joinclauses but none of them use mergejoinable - * operators; nodeMergejoin.c can only do a full join correctly if - * all the joinclauses are mergeclauses. */ if (mergeclauses == NIL) { - if (jointype == JOIN_FULL && restrictlist == NIL) + if (jointype == JOIN_FULL) /* okay to try for mergejoin */ ; else continue;