diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 0d87291025f..07a99e9c6b7 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.162 2007/04/21 06:18:52 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.163 2007/04/21 21:01:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -39,7 +39,8 @@ int geqo_threshold; static void set_base_rel_pathlists(PlannerInfo *root); -static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti); +static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, + Index rti, RangeTblEntry *rte); static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte); static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, @@ -144,7 +145,7 @@ set_base_rel_pathlists(PlannerInfo *root) if (rel->reloptkind != RELOPT_BASEREL) continue; - set_rel_pathlist(root, rel, rti); + set_rel_pathlist(root, rel, rti, root->simple_rte_array[rti]); } } @@ -153,10 +154,9 @@ set_base_rel_pathlists(PlannerInfo *root) * Build access paths for a base relation */ static void -set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti) +set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, + Index rti, RangeTblEntry *rte) { - RangeTblEntry *rte = rt_fetch(rti, root->parse->rtable); - if (rte->inh) { /* It's an "append relation", process accordingly */ @@ -200,8 +200,11 @@ set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) * If we can prove we don't need to scan the rel via constraint exclusion, * set up a single dummy path for it. (Rather than inventing a special * "dummy" path type, we represent this as an AppendPath with no members.) + * We only need to check for regular baserels; if it's an otherrel, CE + * was already checked in set_append_rel_pathlist(). */ - if (relation_excluded_by_constraints(rel, rte)) + if (rel->reloptkind == RELOPT_BASEREL && + relation_excluded_by_constraints(rel, rte)) { /* Set dummy size estimates --- we leave attr_widths[] as zeroes */ rel->rows = 0; @@ -294,6 +297,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, { AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l); int childRTindex; + RangeTblEntry *childRTE; RelOptInfo *childrel; Path *childpath; ListCell *parentvars; @@ -304,6 +308,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, continue; childRTindex = appinfo->child_relid; + childRTE = root->simple_rte_array[childRTindex]; /* * The child rel's RelOptInfo was already created during @@ -313,18 +318,29 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL); /* - * Copy the parent's targetlist and quals to the child, with - * appropriate substitution of variables. + * We have to copy the parent's targetlist and quals to the child, + * with appropriate substitution of variables. However, only the + * baserestrictinfo quals are needed before we can check for + * constraint exclusion; so do that first and then check to see + * if we can disregard this child. */ - childrel->reltargetlist = (List *) - adjust_appendrel_attrs((Node *) rel->reltargetlist, - appinfo); childrel->baserestrictinfo = (List *) adjust_appendrel_attrs((Node *) rel->baserestrictinfo, appinfo); + + if (relation_excluded_by_constraints(childrel, childRTE)) + { + /* this child need not be scanned, so just disregard it */ + continue; + } + + /* CE failed, so finish copying targetlist and join quals */ childrel->joininfo = (List *) adjust_appendrel_attrs((Node *) rel->joininfo, appinfo); + childrel->reltargetlist = (List *) + adjust_appendrel_attrs((Node *) rel->reltargetlist, + appinfo); /* * We have to make child entries in the EquivalenceClass data @@ -353,12 +369,9 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, * It's possible that the child is itself an appendrel, in which case * we can "cut out the middleman" and just add its child paths to our * own list. (We don't try to do this earlier because we need to - * apply both levels of transformation to the quals.) This test also - * handles the case where the child rel need not be scanned because of - * constraint exclusion: it'll have an Append path with no subpaths, - * and will vanish from our list. + * apply both levels of transformation to the quals.) */ - set_rel_pathlist(root, childrel, childRTindex); + set_rel_pathlist(root, childrel, childRTindex, childRTE); childpath = childrel->cheapest_total_path; if (IsA(childpath, AppendPath)) |