diff options
Diffstat (limited to 'src/backend/optimizer/util/pathnode.c')
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 45 |
1 files changed, 29 insertions, 16 deletions
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 36ec025b05b..68dee0f5010 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -2368,9 +2368,9 @@ create_projection_path(PlannerInfo *root, * knows that the given path isn't referenced elsewhere and so can be modified * in-place. * - * If the input path is a GatherPath, we try to push the new target down to - * its input as well; this is a yet more invasive modification of the input - * path, which create_projection_path() can't do. + * If the input path is a GatherPath or GatherMergePath, we try to push the + * new target down to its input as well; this is a yet more invasive + * modification of the input path, which create_projection_path() can't do. * * Note that we mustn't change the source path's parent link; so when it is * add_path'd to "rel" things will be a bit inconsistent. So far that has @@ -2407,31 +2407,44 @@ apply_projection_to_path(PlannerInfo *root, (target->cost.per_tuple - oldcost.per_tuple) * path->rows; /* - * If the path happens to be a Gather path, we'd like to arrange for the - * subpath to return the required target list so that workers can help - * project. But if there is something that is not parallel-safe in the - * target expressions, then we can't. + * If the path happens to be a Gather or GatherMerge path, we'd like to + * arrange for the subpath to return the required target list so that + * workers can help project. But if there is something that is not + * parallel-safe in the target expressions, then we can't. */ - if (IsA(path, GatherPath) && + if ((IsA(path, GatherPath) || IsA(path, GatherMergePath)) && is_parallel_safe(root, (Node *) target->exprs)) { - GatherPath *gpath = (GatherPath *) path; - /* * We always use create_projection_path here, even if the subpath is * projection-capable, so as to avoid modifying the subpath in place. * It seems unlikely at present that there could be any other * references to the subpath, but better safe than sorry. * - * Note that we don't change the GatherPath's cost estimates; it might + * Note that we don't change the parallel path's cost estimates; it might * be appropriate to do so, to reflect the fact that the bulk of the * target evaluation will happen in workers. */ - gpath->subpath = (Path *) - create_projection_path(root, - gpath->subpath->parent, - gpath->subpath, - target); + if (IsA(path, GatherPath)) + { + GatherPath *gpath = (GatherPath *) path; + + gpath->subpath = (Path *) + create_projection_path(root, + gpath->subpath->parent, + gpath->subpath, + target); + } + else + { + GatherMergePath *gmpath = (GatherMergePath *) path; + + gmpath->subpath = (Path *) + create_projection_path(root, + gmpath->subpath->parent, + gmpath->subpath, + target); + } } else if (path->parallel_safe && !is_parallel_safe(root, (Node *) target->exprs)) |