diff options
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index cf46b74782c..fb283184c58 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -1360,8 +1360,12 @@ expand_inherited_tables(PlannerInfo *root) * table, but with inh = false, to represent the parent table in its role * as a simple member of the inheritance set. * - * A childless table is never considered to be an inheritance set; therefore - * a parent RTE must always have at least two associated AppendRelInfos. + * A childless table is never considered to be an inheritance set. For + * regular inheritance, a parent RTE must always have at least two associated + * AppendRelInfos: one corresponding to the parent table as a simple member of + * inheritance set and one or more corresponding to the actual children. + * Since a partitioned table is not scanned, it might have only one associated + * AppendRelInfo. */ static void expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti) @@ -1374,7 +1378,7 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti) List *inhOIDs; List *appinfos; ListCell *l; - bool need_append; + bool has_child; PartitionedChildRelInfo *pcinfo; List *partitioned_child_rels = NIL; @@ -1448,7 +1452,7 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti) /* Scan the inheritance set and expand it */ appinfos = NIL; - need_append = false; + has_child = false; foreach(l, inhOIDs) { Oid childOID = lfirst_oid(l); @@ -1502,7 +1506,10 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti) */ if (childrte->relkind != RELKIND_PARTITIONED_TABLE) { - need_append = true; + /* Remember if we saw a real child. */ + if (childOID != parentOID) + has_child = true; + appinfo = makeNode(AppendRelInfo); appinfo->parent_relid = rti; appinfo->child_relid = childRTindex; @@ -1582,7 +1589,7 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti) * the parent table is harmless, so we don't bother to get rid of it; * ditto for the useless PlanRowMark node. */ - if (!need_append) + if (!has_child) { /* Clear flag before returning */ rte->inh = false; |