From 5b762d96e8c602434bc7e56f910c23c54e95f80d Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 11 Jul 2018 15:25:28 -0400 Subject: [PATCH] Fix create_scan_plan's handling of sortgrouprefs for physical tlists. We should only run apply_pathtarget_labeling_to_tlist if CP_LABEL_TLIST was specified, because only in that case has use_physical_tlist checked that the labeling will succeed; otherwise we may get an "ORDER/GROUP BY expression not found in targetlist" error. (This subsumes the previous test about gating_clauses, because we reset "flags" to zero earlier if there are gating clauses to apply.) The only known case in which a failure can occur is with a ProjectSet path directly atop a table scan path, although it seems likely that there are other cases or will be such in future. This means that the failure is currently only visible in the v10 branch: 9.6 didn't have ProjectSet, while in v11 and HEAD, apply_scanjoin_target_to_paths for some weird reason is using create_projection_path not apply_projection_to_path, masking the problem because there's a ProjectionPath in between. Nonetheless this code is clearly wrong on its own terms, so back-patch to 9.6 where this logic was introduced. Per report from Regina Obe. Discussion: https://postgr.es/m/001501d40f88$75186950$5f493bf0$@pcorp.us --- src/backend/optimizer/plan/createplan.c | 10 +++++----- src/test/regress/expected/tsrf.out | 22 ++++++++++++++++++++++ src/test/regress/sql/tsrf.sql | 5 +++++ 3 files changed, 32 insertions(+), 5 deletions(-) diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 4186e20d56..165a9e9b8e 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -579,10 +579,10 @@ create_scan_plan(PlannerInfo *root, Path *best_path, int flags) tlist = copyObject(((IndexPath *) best_path)->indexinfo->indextlist); /* - * Transfer any sortgroupref data to the replacement tlist, unless - * we don't care because the gating Result will handle it. + * Transfer sortgroupref data to the replacement tlist, if + * requested (use_physical_tlist checked that this will work). */ - if (!gating_clauses) + if (flags & CP_LABEL_TLIST) apply_pathtarget_labeling_to_tlist(tlist, best_path->pathtarget); } else @@ -596,7 +596,7 @@ create_scan_plan(PlannerInfo *root, Path *best_path, int flags) else { /* As above, transfer sortgroupref data to replacement tlist */ - if (!gating_clauses) + if (flags & CP_LABEL_TLIST) apply_pathtarget_labeling_to_tlist(tlist, best_path->pathtarget); } } @@ -1639,7 +1639,7 @@ create_projection_plan(PlannerInfo *root, ProjectionPath *best_path, int flags) */ subplan = create_plan_recurse(root, best_path->subpath, 0); tlist = subplan->targetlist; - if ((flags & CP_LABEL_TLIST) != 0) + if (flags & CP_LABEL_TLIST) apply_pathtarget_labeling_to_tlist(tlist, best_path->path.pathtarget); } diff --git a/src/test/regress/expected/tsrf.out b/src/test/regress/expected/tsrf.out index 6d33fbd3c8..25be6b9ab1 100644 --- a/src/test/regress/expected/tsrf.out +++ b/src/test/regress/expected/tsrf.out @@ -421,6 +421,28 @@ SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(d (24 rows) reset enable_hashagg; +-- case with degenerate ORDER BY +explain (verbose, costs off) +select 'foo' as f, generate_series(1,2) as g from few order by 1; + QUERY PLAN +---------------------------------------------- + ProjectSet + Output: 'foo'::text, generate_series(1, 2) + -> Seq Scan on public.few + Output: id, dataa, datab +(4 rows) + +select 'foo' as f, generate_series(1,2) as g from few order by 1; + f | g +-----+--- + foo | 1 + foo | 2 + foo | 1 + foo | 2 + foo | 1 + foo | 2 +(6 rows) + -- data modification CREATE TABLE fewmore AS SELECT generate_series(1,3) AS data; INSERT INTO fewmore VALUES(generate_series(4,5)); diff --git a/src/test/regress/sql/tsrf.sql b/src/test/regress/sql/tsrf.sql index ae1900bce1..0a1e8e5666 100644 --- a/src/test/regress/sql/tsrf.sql +++ b/src/test/regress/sql/tsrf.sql @@ -88,6 +88,11 @@ SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(d SELECT dataa, datab b, generate_series(1,2) g, count(*) FROM few GROUP BY CUBE(dataa, datab, g) ORDER BY g; reset enable_hashagg; +-- case with degenerate ORDER BY +explain (verbose, costs off) +select 'foo' as f, generate_series(1,2) as g from few order by 1; +select 'foo' as f, generate_series(1,2) as g from few order by 1; + -- data modification CREATE TABLE fewmore AS SELECT generate_series(1,3) AS data; INSERT INTO fewmore VALUES(generate_series(4,5)); -- 2.40.0