diff options
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 1 | ||||
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 19 |
2 files changed, 19 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 83e8b34b1bc..66c5e3ee80f 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -1845,6 +1845,7 @@ create_projection_plan(PlannerInfo *root, ProjectionPath *best_path, int flags) */ subplan = create_plan_recurse(root, best_path->subpath, CP_IGNORE_TLIST); + Assert(is_projection_capable_plan(subplan)); tlist = build_path_tlist(root, &best_path->path); } else diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 056f7422c19..ffc03238c56 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -2579,7 +2579,23 @@ create_projection_path(PlannerInfo *root, PathTarget *target) { ProjectionPath *pathnode = makeNode(ProjectionPath); - PathTarget *oldtarget = subpath->pathtarget; + PathTarget *oldtarget; + + /* + * We mustn't put a ProjectionPath directly above another; it's useless + * and will confuse create_projection_plan. Rather than making sure all + * callers handle that, let's implement it here, by stripping off any + * ProjectionPath in what we're given. Given this rule, there won't be + * more than one. + */ + if (IsA(subpath, ProjectionPath)) + { + ProjectionPath *subpp = (ProjectionPath *) subpath; + + Assert(subpp->path.parent == rel); + subpath = subpp->subpath; + Assert(!IsA(subpath, ProjectionPath)); + } pathnode->path.pathtype = T_Result; pathnode->path.parent = rel; @@ -2605,6 +2621,7 @@ create_projection_path(PlannerInfo *root, * Note: in the latter case, create_projection_plan has to recheck our * conclusion; see comments therein. */ + oldtarget = subpath->pathtarget; if (is_projection_capable_path(subpath) || equal(oldtarget->exprs, target->exprs)) { |