diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 80 |
1 files changed, 50 insertions, 30 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 90add90e4e9..890bb59a12f 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 1.140 2006/01/31 21:39:23 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.141 2006/02/03 21:08:49 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -42,6 +42,8 @@ int geqo_threshold; static void set_base_rel_pathlists(PlannerInfo *root); +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, @@ -133,7 +135,6 @@ set_base_rel_pathlists(PlannerInfo *root) for (rti = 1; rti < root->simple_rel_array_size; rti++) { RelOptInfo *rel = root->simple_rel_array[rti]; - RangeTblEntry *rte; /* there may be empty slots corresponding to non-baserel RTEs */ if (rel == NULL) @@ -145,33 +146,44 @@ set_base_rel_pathlists(PlannerInfo *root) if (rel->reloptkind != RELOPT_BASEREL) continue; - rte = rt_fetch(rti, root->parse->rtable); + set_rel_pathlist(root, rel, rti, + rt_fetch(rti, root->parse->rtable)); + } +} - if (rte->inh) - { - /* It's an "append relation", process accordingly */ - set_append_rel_pathlist(root, rel, rti, rte); - } - else if (rel->rtekind == RTE_SUBQUERY) - { - /* Subquery --- generate a separate plan for it */ - set_subquery_pathlist(root, rel, rti, rte); - } - else if (rel->rtekind == RTE_FUNCTION) - { - /* RangeFunction --- generate a separate plan for it */ - set_function_pathlist(root, rel, rte); - } - else - { - /* Plain relation */ - set_plain_rel_pathlist(root, rel, rte); - } +/* + * set_rel_pathlist + * Build access paths for a base relation + */ +static void +set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, + Index rti, RangeTblEntry *rte) +{ + if (rte->inh) + { + /* It's an "append relation", process accordingly */ + set_append_rel_pathlist(root, rel, rti, rte); + } + else if (rel->rtekind == RTE_SUBQUERY) + { + /* Subquery --- generate a separate plan for it */ + set_subquery_pathlist(root, rel, rti, rte); + } + else if (rel->rtekind == RTE_FUNCTION) + { + /* RangeFunction --- generate a separate plan for it */ + set_function_pathlist(root, rel, rte); + } + else + { + /* Plain relation */ + Assert(rel->rtekind == RTE_RELATION); + set_plain_rel_pathlist(root, rel, rte); + } #ifdef OPTIMIZER_DEBUG - debug_print_rel(root, rel); + debug_print_rel(root, rel); #endif - } } /* @@ -181,9 +193,6 @@ set_base_rel_pathlists(PlannerInfo *root) static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) { - Assert(rel->rtekind == RTE_RELATION); - Assert(!rte->inh); - /* Mark rel with estimated output rows, width, etc */ set_baserel_size_estimates(root, rel); @@ -265,6 +274,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, int childRTindex; RelOptInfo *childrel; RangeTblEntry *childrte; + Path *childpath; ListCell *parentvars; ListCell *childvars; @@ -346,10 +356,20 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, /* * Compute the child's access paths, and save the cheapest. + * + * 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.) */ - set_plain_rel_pathlist(root, childrel, childrte); + set_rel_pathlist(root, childrel, childRTindex, childrte); - subpaths = lappend(subpaths, childrel->cheapest_total_path); + childpath = childrel->cheapest_total_path; + if (IsA(childpath, AppendPath)) + subpaths = list_concat(subpaths, + ((AppendPath *) childpath)->subpaths); + else + subpaths = lappend(subpaths, childpath); /* * Propagate size information from the child back to the parent. For |