diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 120 |
1 files changed, 115 insertions, 5 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 3dc41c68073..a942249fd09 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 1.173 2008/08/25 22:42:32 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.174 2008/10/04 21:56:53 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -57,6 +57,10 @@ static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte); static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte); +static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, + RangeTblEntry *rte); +static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, + RangeTblEntry *rte); static RelOptInfo *make_rel_from_joinlist(PlannerInfo *root, List *joinlist); static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, bool *differentTypes); @@ -173,14 +177,22 @@ set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, } else if (rel->rtekind == RTE_FUNCTION) { - /* RangeFunction --- generate a separate plan for it */ + /* RangeFunction --- generate a suitable path for it */ set_function_pathlist(root, rel, rte); } else if (rel->rtekind == RTE_VALUES) { - /* Values list --- generate a separate plan for it */ + /* Values list --- generate a suitable path for it */ set_values_pathlist(root, rel, rte); } + else if (rel->rtekind == RTE_CTE) + { + /* CTE reference --- generate a suitable path for it */ + if (rte->self_reference) + set_worktable_pathlist(root, rel, rte); + else + set_cte_pathlist(root, rel, rte); + } else { /* Plain relation */ @@ -585,8 +597,8 @@ set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, /* Generate the plan for the subquery */ rel->subplan = subquery_planner(root->glob, subquery, - root->query_level + 1, - tuple_fraction, + root, + false, tuple_fraction, &subroot); rel->subrtable = subroot->parse->rtable; @@ -641,6 +653,104 @@ set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) } /* + * set_cte_pathlist + * Build the (single) access path for a non-self-reference CTE RTE + */ +static void +set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) +{ + Plan *cteplan; + PlannerInfo *cteroot; + Index levelsup; + int ndx; + ListCell *lc; + int plan_id; + + /* + * Find the referenced CTE, and locate the plan previously made for it. + */ + levelsup = rte->ctelevelsup; + cteroot = root; + while (levelsup-- > 0) + { + cteroot = cteroot->parent_root; + if (!cteroot) /* shouldn't happen */ + elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename); + } + /* + * Note: cte_plan_ids can be shorter than cteList, if we are still working + * on planning the CTEs (ie, this is a side-reference from another CTE). + * So we mustn't use forboth here. + */ + ndx = 0; + foreach(lc, cteroot->parse->cteList) + { + CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc); + + if (strcmp(cte->ctename, rte->ctename) == 0) + break; + ndx++; + } + if (lc == NULL) /* shouldn't happen */ + elog(ERROR, "could not find CTE \"%s\"", rte->ctename); + if (ndx >= list_length(cteroot->cte_plan_ids)) + elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename); + plan_id = list_nth_int(cteroot->cte_plan_ids, ndx); + Assert(plan_id > 0); + cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1); + + /* Mark rel with estimated output rows, width, etc */ + set_cte_size_estimates(root, rel, cteplan); + + /* Generate appropriate path */ + add_path(rel, create_ctescan_path(root, rel)); + + /* Select cheapest path (pretty easy in this case...) */ + set_cheapest(rel); +} + +/* + * set_worktable_pathlist + * Build the (single) access path for a self-reference CTE RTE + */ +static void +set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) +{ + Plan *cteplan; + PlannerInfo *cteroot; + Index levelsup; + + /* + * We need to find the non-recursive term's plan, which is in the plan + * level that's processing the recursive UNION, which is one level + * *below* where the CTE comes from. + */ + levelsup = rte->ctelevelsup; + if (levelsup == 0) /* shouldn't happen */ + elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename); + levelsup--; + cteroot = root; + while (levelsup-- > 0) + { + cteroot = cteroot->parent_root; + if (!cteroot) /* shouldn't happen */ + elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename); + } + cteplan = cteroot->non_recursive_plan; + if (!cteplan) /* shouldn't happen */ + elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename); + + /* Mark rel with estimated output rows, width, etc */ + set_cte_size_estimates(root, rel, cteplan); + + /* Generate appropriate path */ + add_path(rel, create_worktablescan_path(root, rel)); + + /* Select cheapest path (pretty easy in this case...) */ + set_cheapest(rel); +} + +/* * make_rel_from_joinlist * Build access paths using a "joinlist" to guide the join path search. * |