diff options
Diffstat (limited to 'src/backend/optimizer/plan/analyzejoins.c')
| -rw-r--r-- | src/backend/optimizer/plan/analyzejoins.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c index c053e32e54d..fb01fbe357a 100644 --- a/src/backend/optimizer/plan/analyzejoins.c +++ b/src/backend/optimizer/plan/analyzejoins.c @@ -1658,6 +1658,28 @@ update_eclasses(EquivalenceClass *ec, int from, int to) } /* + * "Logically" compares two RestrictInfo's ignoring the 'rinfo_serial' field, + * which makes almost every RestrictInfo unique. This type of comparison is + * useful when removing duplicates while moving RestrictInfo's from removed + * relation to remaining relation during self-join elimination. + * + * XXX: In the future, we might remove the 'rinfo_serial' field completely and + * get rid of this function. + */ +static bool +restrict_infos_logically_equal(RestrictInfo *a, RestrictInfo *b) +{ + int saved_rinfo_serial = a->rinfo_serial; + bool result; + + a->rinfo_serial = b->rinfo_serial; + result = equal(a, b); + a->rinfo_serial = saved_rinfo_serial; + + return result; +} + +/* * Remove a relation after we have proven that it participates only in an * unneeded unique self join. * @@ -1760,7 +1782,7 @@ remove_self_join_rel(PlannerInfo *root, PlanRowMark *kmark, PlanRowMark *rmark, if (src == rinfo || (rinfo->parent_ec != NULL && src->parent_ec == rinfo->parent_ec) - || equal(rinfo->clause, src->clause)) + || restrict_infos_logically_equal(rinfo, src)) { is_redundant = true; break; @@ -1788,7 +1810,7 @@ remove_self_join_rel(PlannerInfo *root, PlanRowMark *kmark, PlanRowMark *rmark, if (src == rinfo || (rinfo->parent_ec != NULL && src->parent_ec == rinfo->parent_ec) - || equal(rinfo->clause, src->clause)) + || restrict_infos_logically_equal(rinfo, src)) { is_redundant = true; break; |