diff options
Diffstat (limited to 'contrib/postgres_fdw/postgres_fdw.c')
| -rw-r--r-- | contrib/postgres_fdw/postgres_fdw.c | 120 |
1 files changed, 83 insertions, 37 deletions
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 76d0e158519..40bffd6f6cb 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -283,9 +283,6 @@ static void postgresGetForeignJoinPaths(PlannerInfo *root, JoinPathExtraData *extra); static bool postgresRecheckForeignScan(ForeignScanState *node, TupleTableSlot *slot); -static List *get_useful_pathkeys_for_relation(PlannerInfo *root, - RelOptInfo *rel); -static List *get_useful_ecs_for_relation(PlannerInfo *root, RelOptInfo *rel); /* * Helper functions @@ -331,6 +328,11 @@ static void conversion_error_callback(void *arg); static bool foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, RelOptInfo *outerrel, RelOptInfo *innerrel, JoinPathExtraData *extra); +static List *get_useful_pathkeys_for_relation(PlannerInfo *root, + RelOptInfo *rel); +static List *get_useful_ecs_for_relation(PlannerInfo *root, RelOptInfo *rel); +static void add_paths_with_pathkeys_for_rel(PlannerInfo *root, RelOptInfo *rel, + Path *epq_path); /* @@ -503,6 +505,14 @@ postgresGetForeignRelSize(PlannerInfo *root, cost_qual_eval(&fpinfo->local_conds_cost, fpinfo->local_conds, root); /* + * Set cached relation costs to some negative value, so that we can detect + * when they are set to some sensible costs during one (usually the first) + * of the calls to estimate_path_cost_size(). + */ + fpinfo->rel_startup_cost = -1; + fpinfo->rel_total_cost = -1; + + /* * If the table or the server is configured to use remote estimates, * connect to the foreign server and execute EXPLAIN to estimate the * number of rows selected by the restriction clauses, as well as the @@ -774,7 +784,6 @@ postgresGetForeignPaths(PlannerInfo *root, ForeignPath *path; List *ppi_list; ListCell *lc; - List *useful_pathkeys_list = NIL; /* List of all pathkeys */ /* * Create simplest ForeignScan path node and add it to baserel. This path @@ -793,30 +802,8 @@ postgresGetForeignPaths(PlannerInfo *root, NIL); /* no fdw_private list */ add_path(baserel, (Path *) path); - useful_pathkeys_list = get_useful_pathkeys_for_relation(root, baserel); - - /* Create one path for each set of pathkeys we found above. */ - foreach(lc, useful_pathkeys_list) - { - double rows; - int width; - Cost startup_cost; - Cost total_cost; - List *useful_pathkeys = lfirst(lc); - - estimate_path_cost_size(root, baserel, NIL, useful_pathkeys, - &rows, &width, &startup_cost, &total_cost); - - add_path(baserel, (Path *) - create_foreignscan_path(root, baserel, - rows, - startup_cost, - total_cost, - useful_pathkeys, - NULL, - NULL, - NIL)); - } + /* Add paths with pathkeys */ + add_paths_with_pathkeys_for_rel(root, baserel, NULL); /* * If we're not using remote estimates, stop here. We have no way to @@ -2182,7 +2169,18 @@ estimate_path_cost_size(PlannerInfo *root, /* Back into an estimate of the number of retrieved rows. */ retrieved_rows = clamp_row_est(rows / fpinfo->local_conds_sel); - if (foreignrel->reloptkind != RELOPT_JOINREL) + /* + * We will come here again and again with different set of pathkeys + * that caller wants to cost. We don't need to calculate the cost of + * bare scan each time. Instead, use the costs if we have cached them + * already. + */ + if (fpinfo->rel_startup_cost > 0 && fpinfo->rel_total_cost > 0) + { + startup_cost = fpinfo->rel_startup_cost; + run_cost = fpinfo->rel_total_cost - fpinfo->rel_startup_cost; + } + else if (foreignrel->reloptkind != RELOPT_JOINREL) { /* Clamp retrieved rows estimates to at most foreignrel->tuples. */ retrieved_rows = Min(retrieved_rows, foreignrel->tuples); @@ -2284,13 +2282,19 @@ estimate_path_cost_size(PlannerInfo *root, } /* - * Cache the costs prior to adding the costs for transferring data from - * the foreign server. These costs are useful for costing the join between - * this relation and another foreign relation, when the cost of join can - * not be obtained from the foreign server. + * Cache the costs for scans without any pathkeys or parameterization + * before adding the costs for transferring data from the foreign server. + * These costs are useful for costing the join between this relation and + * another foreign relation or to calculate the costs of paths with + * pathkeys for this relation, when the costs can not be obtained from the + * foreign server. This function will be called at least once for every + * foreign relation without pathkeys and parameterization. */ - fpinfo->rel_startup_cost = startup_cost; - fpinfo->rel_total_cost = total_cost; + if (pathkeys == NIL && param_join_conds == NIL) + { + fpinfo->rel_startup_cost = startup_cost; + fpinfo->rel_total_cost = total_cost; + } /* * Add some additional cost factors to account for connection overhead @@ -3458,6 +3462,14 @@ foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, fpinfo->fdw_startup_cost = fpinfo_o->fdw_startup_cost; fpinfo->fdw_tuple_cost = fpinfo_o->fdw_tuple_cost; + /* + * Set cached relation costs to some negative value, so that we can detect + * when they are set to some sensible costs, during one (usually the + * first) of the calls to estimate_path_cost_size(). + */ + fpinfo->rel_startup_cost = -1; + fpinfo->rel_total_cost = -1; + /* Mark that this join can be pushed down safely */ fpinfo->pushdown_safe = true; @@ -3532,6 +3544,39 @@ foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, return true; } +static void +add_paths_with_pathkeys_for_rel(PlannerInfo *root, RelOptInfo *rel, + Path *epq_path) +{ + List *useful_pathkeys_list = NIL; /* List of all pathkeys */ + ListCell *lc; + + useful_pathkeys_list = get_useful_pathkeys_for_relation(root, rel); + + /* Create one path for each set of pathkeys we found above. */ + foreach(lc, useful_pathkeys_list) + { + double rows; + int width; + Cost startup_cost; + Cost total_cost; + List *useful_pathkeys = lfirst(lc); + + estimate_path_cost_size(root, rel, NIL, useful_pathkeys, + &rows, &width, &startup_cost, &total_cost); + + add_path(rel, (Path *) + create_foreignscan_path(root, rel, + rows, + startup_cost, + total_cost, + useful_pathkeys, + NULL, + epq_path, + NIL)); + } +} + /* * postgresGetForeignJoinPaths * Add possible ForeignPath to joinrel, if join is safe to push down. @@ -3670,7 +3715,8 @@ postgresGetForeignJoinPaths(PlannerInfo *root, /* Add generated path into joinrel by add_path(). */ add_path(joinrel, (Path *) joinpath); - /* XXX Consider pathkeys for the join relation */ + /* Consider pathkeys for the join relation */ + add_paths_with_pathkeys_for_rel(root, joinrel, epq_path); /* XXX Consider parameterized paths for the join relation */ } @@ -3877,7 +3923,7 @@ find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel) { EquivalenceMember *em = lfirst(lc_em); - if (bms_equal(em->em_relids, rel->relids)) + if (bms_is_subset(em->em_relids, rel->relids)) { /* * If there is more than one equivalence member whose Vars are |