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Prevent improper reordering of antijoins vs. outer joins.

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An outer join appearing within the RHS of an antijoin can't commute with
the antijoin, but somehow I missed teaching make_outerjoininfo() about
that.  In Teodor Sigaev's recent trouble report, this manifests as a
"could not find RelOptInfo for given relids" error within eqjoinsel();
but I think silently wrong query results are possible too, if the planner
misorders the joins and doesn't happen to trigger any internal consistency
checks.  It's broken as far back as we had antijoins, so back-patch to all
supported branches.
This commit is contained in:
Tom Lane
2015-04-25 16:44:27 -04:00
parent 854adb8371
commit 3cf8686014
3 changed files with 63 additions and 3 deletions
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7
src/backend/optimizer/plan/initsplan.c
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@ -1165,9 +1165,9 @@ make_outerjoininfo(PlannerInfo *root,
* For a lower OJ in our RHS, if our join condition does not use the
* lower join's RHS and the lower OJ's join condition is strict, we
* can interchange the ordering of the two OJs; otherwise we must add
* lower OJ's full syntactic relset to min_righthand. Here, we must
* preserve ordering anyway if either the current join is a semijoin,
* or the lower OJ is either a semijoin or an antijoin.
* the lower OJ's full syntactic relset to min_righthand. Also, we
* must preserve ordering anyway if either the current join or the
* lower OJ is either a semijoin or an antijoin.
*
* Here, we have to consider that "our join condition" includes any
* clauses that syntactically appeared above the lower OJ and below
@ -1184,6 +1184,7 @@ make_outerjoininfo(PlannerInfo *root,
{
if (bms_overlap(clause_relids, otherinfo->syn_righthand) ||
jointype == JOIN_SEMI ||
jointype == JOIN_ANTI ||
otherinfo->jointype == JOIN_SEMI ||
otherinfo->jointype == JOIN_ANTI ||
!otherinfo->lhs_strict || otherinfo->delay_upper_joins)