diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index f8f4e0b68f3..2091f715d32 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -1607,7 +1607,7 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel, * Consider an append of unordered, unparameterized partial paths. Make * it parallel-aware if possible. */ - if (partial_subpaths_valid) + if (partial_subpaths_valid && partial_subpaths != NIL) { AppendPath *appendpath; ListCell *lc; @@ -2004,9 +2004,11 @@ accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths) * Build a dummy path for a relation that's been excluded by constraints * * Rather than inventing a special "dummy" path type, we represent this as an - * AppendPath with no members (see also IS_DUMMY_PATH/IS_DUMMY_REL macros). + * AppendPath with no members (see also IS_DUMMY_APPEND/IS_DUMMY_REL macros). * - * This is exported because inheritance_planner() has need for it. + * (See also mark_dummy_rel, which does basically the same thing, but is + * typically used to change a rel into dummy state after we already made + * paths for it.) */ void set_dummy_rel_pathlist(RelOptInfo *rel) @@ -2019,14 +2021,15 @@ set_dummy_rel_pathlist(RelOptInfo *rel) rel->pathlist = NIL; rel->partial_pathlist = NIL; + /* Set up the dummy path */ add_path(rel, (Path *) create_append_path(NULL, rel, NIL, NIL, NULL, 0, false, NIL, -1)); /* - * We set the cheapest path immediately, to ensure that IS_DUMMY_REL() - * will recognize the relation as dummy if anyone asks. This is redundant - * when we're called from set_rel_size(), but not when called from - * elsewhere, and doing it twice is harmless anyway. + * We set the cheapest-path fields immediately, just in case they were + * pointing at some discarded path. This is redundant when we're called + * from set_rel_size(), but not when called from elsewhere, and doing it + * twice is harmless anyway. */ set_cheapest(rel); } @@ -3552,12 +3555,12 @@ generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel) /* Add partitionwise join paths for partitioned child-joins. */ generate_partitionwise_join_paths(root, child_rel); + set_cheapest(child_rel); + /* Dummy children will not be scanned, so ignore those. */ if (IS_DUMMY_REL(child_rel)) continue; - set_cheapest(child_rel); - #ifdef OPTIMIZER_DEBUG debug_print_rel(root, child_rel); #endif |