diff options
Diffstat (limited to 'src/backend/optimizer/geqo/geqo_eval.c')
| -rw-r--r-- | src/backend/optimizer/geqo/geqo_eval.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/src/backend/optimizer/geqo/geqo_eval.c b/src/backend/optimizer/geqo/geqo_eval.c index 0be2a73e05b..3ef7d7d8aa2 100644 --- a/src/backend/optimizer/geqo/geqo_eval.c +++ b/src/backend/optimizer/geqo/geqo_eval.c @@ -40,7 +40,7 @@ typedef struct } Clump; static List *merge_clump(PlannerInfo *root, List *clumps, Clump *new_clump, - bool force); + int num_gene, bool force); static bool desirable_join(PlannerInfo *root, RelOptInfo *outer_rel, RelOptInfo *inner_rel); @@ -196,7 +196,7 @@ gimme_tree(PlannerInfo *root, Gene *tour, int num_gene) cur_clump->size = 1; /* Merge it into the clumps list, using only desirable joins */ - clumps = merge_clump(root, clumps, cur_clump, false); + clumps = merge_clump(root, clumps, cur_clump, num_gene, false); } if (list_length(clumps) > 1) @@ -210,7 +210,7 @@ gimme_tree(PlannerInfo *root, Gene *tour, int num_gene) { Clump *clump = (Clump *) lfirst(lc); - fclumps = merge_clump(root, fclumps, clump, true); + fclumps = merge_clump(root, fclumps, clump, num_gene, true); } clumps = fclumps; } @@ -235,7 +235,8 @@ gimme_tree(PlannerInfo *root, Gene *tour, int num_gene) * "desirable" joins. */ static List * -merge_clump(PlannerInfo *root, List *clumps, Clump *new_clump, bool force) +merge_clump(PlannerInfo *root, List *clumps, Clump *new_clump, int num_gene, + bool force) { ListCell *prev; ListCell *lc; @@ -267,8 +268,14 @@ merge_clump(PlannerInfo *root, List *clumps, Clump *new_clump, bool force) /* Create paths for partitionwise joins. */ generate_partitionwise_join_paths(root, joinrel); - /* Create GatherPaths for any useful partial paths for rel */ - generate_gather_paths(root, joinrel, false); + /* + * Except for the topmost scan/join rel, consider gathering + * partial paths. We'll do the same for the topmost scan/join + * rel once we know the final targetlist (see + * grouping_planner). + */ + if (old_clump->size + new_clump->size < num_gene) + generate_gather_paths(root, joinrel, false); /* Find and save the cheapest paths for this joinrel */ set_cheapest(joinrel); @@ -286,7 +293,7 @@ merge_clump(PlannerInfo *root, List *clumps, Clump *new_clump, bool force) * others. When no further merge is possible, we'll reinsert * it into the list. */ - return merge_clump(root, clumps, old_clump, force); + return merge_clump(root, clumps, old_clump, num_gene, force); } } prev = lc; |