diff options
Diffstat (limited to 'src/backend/optimizer/plan/createplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 50 |
1 files changed, 37 insertions, 13 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index da7a92081af..91cf78233d5 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -1407,20 +1407,10 @@ create_unique_plan(PlannerInfo *root, UniquePath *best_path, int flags) } } + /* Use change_plan_targetlist in case we need to insert a Result node */ if (newitems || best_path->umethod == UNIQUE_PATH_SORT) - { - /* - * If the top plan node can't do projections and its existing target - * list isn't already what we need, we need to add a Result node to - * help it along. - */ - if (!is_projection_capable_plan(subplan) && - !tlist_same_exprs(newtlist, subplan->targetlist)) - subplan = inject_projection_plan(subplan, newtlist, - best_path->path.parallel_safe); - else - subplan->targetlist = newtlist; - } + subplan = change_plan_targetlist(subplan, newtlist, + best_path->path.parallel_safe); /* * Build control information showing which subplan output columns are to @@ -1763,6 +1753,40 @@ inject_projection_plan(Plan *subplan, List *tlist, bool parallel_safe) } /* + * change_plan_targetlist + * Externally available wrapper for inject_projection_plan. + * + * This is meant for use by FDW plan-generation functions, which might + * want to adjust the tlist computed by some subplan tree. In general, + * a Result node is needed to compute the new tlist, but we can optimize + * some cases. + * + * In most cases, tlist_parallel_safe can just be passed as the parallel_safe + * flag of the FDW's own Path node. + */ +Plan * +change_plan_targetlist(Plan *subplan, List *tlist, bool tlist_parallel_safe) +{ + /* + * If the top plan node can't do projections and its existing target list + * isn't already what we need, we need to add a Result node to help it + * along. + */ + if (!is_projection_capable_plan(subplan) && + !tlist_same_exprs(tlist, subplan->targetlist)) + subplan = inject_projection_plan(subplan, tlist, + subplan->parallel_safe && + tlist_parallel_safe); + else + { + /* Else we can just replace the plan node's tlist */ + subplan->targetlist = tlist; + subplan->parallel_safe &= tlist_parallel_safe; + } + return subplan; +} + +/* * create_sort_plan * * Create a Sort plan for 'best_path' and (recursively) plans |