diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 4a330192f26..479a694bcac 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -979,8 +979,10 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel, int childRTindex; RangeTblEntry *childRTE; RelOptInfo *childrel; + List *childrinfos; ListCell *parentvars; ListCell *childvars; + ListCell *lc; /* append_rel_list contains all append rels; ignore others */ if (appinfo->parent_relid != parentRTindex) @@ -1021,6 +1023,28 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel, * Constraint exclusion failed, so copy the parent's join quals and * targetlist to the child, with appropriate variable substitutions. * + * We skip join quals that came from above outer joins that can null + * this rel, since they would be of no value while generating paths + * for the child. This saves some effort while processing the child + * rel, and it also avoids an implementation restriction in + * adjust_appendrel_attrs (it can't apply nullingrels to a non-Var). + */ + childrinfos = NIL; + foreach(lc, rel->joininfo) + { + RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc); + + if (!bms_overlap(rinfo->clause_relids, rel->nulling_relids)) + childrinfos = lappend(childrinfos, + adjust_appendrel_attrs(root, + (Node *) rinfo, + 1, &appinfo)); + } + childrel->joininfo = childrinfos; + + /* + * Now for the child's targetlist. + * * NB: the resulting childrel->reltarget->exprs may contain arbitrary * expressions, which otherwise would not occur in a rel's targetlist. * Code that might be looking at an appendrel child must cope with @@ -1028,10 +1052,6 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel, * PlaceHolderVars.) XXX we do not bother to update the cost or width * fields of childrel->reltarget; not clear if that would be useful. */ - childrel->joininfo = (List *) - adjust_appendrel_attrs(root, - (Node *) rel->joininfo, - 1, &appinfo); childrel->reltarget->exprs = (List *) adjust_appendrel_attrs(root, (Node *) rel->reltarget->exprs, |