From: Tom Lane Date: Tue, 24 May 2005 18:02:55 +0000 (+0000) Subject: Previous fix for "x FULL JOIN y ON true" failed to handle the case X-Git-Tag: REL8_0_4~88 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a94ace0796b8719c6685351b02fe93459c206c38;p=thirdparty%2Fpostgresql.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 0a2619d8f5e..6bc24fc258b 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/joinpath.c,v 1.91.4.1 2005/01/23 02:22:27 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/joinpath.c,v 1.91.4.2 2005/05/24 18:02:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -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;