From 8e72239e9d961c27f02b242e33fa832c364c7a4b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 14 Jun 2017 11:10:05 -0400 Subject: [PATCH] Fix no-longer-valid shortcuts in expression_returns_set(). expression_returns_set() used to short-circuit its recursion upon seeing certain node types, such as DistinctExpr, that it knew the executor did not support set-valued arguments for. That was never inherent, though, just a reflection of laziness in execQual.c. With the new implementation of SRFs there is no reason to think that any scalar-valued expression node could not have a set-valued subexpression, except for AggRefs and WindowFuncs where we know there is a parser check rejecting it. And indeed, the shortcut causes unexpected failures for cases such as a SRF underneath DistinctExpr, because the planner stops looking for SRFs too soon. Discussion: https://postgr.es/m/5259.1497044025@sss.pgh.pa.us --- src/backend/nodes/nodeFuncs.c | 30 +----------------------------- src/test/regress/expected/tsrf.out | 8 ++++++++ src/test/regress/sql/tsrf.sql | 1 + 3 files changed, 10 insertions(+), 29 deletions(-) diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c index 41f3408cfc..5af37a9388 100644 --- a/src/backend/nodes/nodeFuncs.c +++ b/src/backend/nodes/nodeFuncs.c @@ -694,39 +694,11 @@ expression_returns_set_walker(Node *node, void *context) /* else fall through to check args */ } - /* Avoid recursion for some cases that can't return a set */ + /* Avoid recursion for some cases that parser checks not to return a set */ if (IsA(node, Aggref)) return false; if (IsA(node, WindowFunc)) return false; - if (IsA(node, DistinctExpr)) - return false; - if (IsA(node, NullIfExpr)) - return false; - if (IsA(node, ScalarArrayOpExpr)) - return false; - if (IsA(node, BoolExpr)) - return false; - if (IsA(node, SubLink)) - return false; - if (IsA(node, SubPlan)) - return false; - if (IsA(node, AlternativeSubPlan)) - return false; - if (IsA(node, ArrayExpr)) - return false; - if (IsA(node, RowExpr)) - return false; - if (IsA(node, RowCompareExpr)) - return false; - if (IsA(node, CoalesceExpr)) - return false; - if (IsA(node, MinMaxExpr)) - return false; - if (IsA(node, SQLValueFunction)) - return false; - if (IsA(node, XmlExpr)) - return false; return expression_tree_walker(node, expression_returns_set_walker, context); diff --git a/src/test/regress/expected/tsrf.out b/src/test/regress/expected/tsrf.out index ef02ba7465..b691abe714 100644 --- a/src/test/regress/expected/tsrf.out +++ b/src/test/regress/expected/tsrf.out @@ -443,6 +443,14 @@ SELECT int4mul(generate_series(1,2), 10); 20 (2 rows) +SELECT generate_series(1,3) IS DISTINCT FROM 2; + ?column? +---------- + t + f + t +(3 rows) + -- but SRFs in function RTEs must be at top level (annoying restriction) SELECT * FROM int4mul(generate_series(1,2), 10); ERROR: set-returning functions must appear at top level of FROM diff --git a/src/test/regress/sql/tsrf.sql b/src/test/regress/sql/tsrf.sql index 45de099e4d..0be7530beb 100644 --- a/src/test/regress/sql/tsrf.sql +++ b/src/test/regress/sql/tsrf.sql @@ -98,6 +98,7 @@ VALUES(1, generate_series(1,2)); -- We allow tSRFs that are not at top level SELECT int4mul(generate_series(1,2), 10); +SELECT generate_series(1,3) IS DISTINCT FROM 2; -- but SRFs in function RTEs must be at top level (annoying restriction) SELECT * FROM int4mul(generate_series(1,2), 10); -- 2.40.0