From 89b69db82adf742cadc36ee9a365cf47a632cdb0 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 8 Jan 2024 11:48:44 -0500 Subject: [PATCH] Allow examine_simple_variable() to work on INSERT RETURNING Vars. Since commit 599b33b94, this function assumed that every RTE_RELATION RangeTblEntry would have an associated RelOptInfo. But that's not so: we only build RelOptInfos for relations that are scanned by the query. In particular the target of an INSERT won't have one, so that Vars appearing in an INSERT ... RETURNING list will not have an associated RelOptInfo. This apparently wasn't a problem before commit f7816aec2 taught examine_simple_variable() to drill down into CTEs containing INSERT RETURNING, but it is now. To fix, add a fallback code path that gets the userid to use directly from the RTEPermissionInfo associated with the RTE. (Sadly, we must have two code paths, because not every RTE has a RTEPermissionInfo either.) Per report from Alexander Lakhin. No back-patch, since the case is apparently unreachable before f7816aec2. Discussion: https://postgr.es/m/608a4886-6c60-0f9e-97d5-591256bd4150@gmail.com --- src/backend/optimizer/util/relnode.c | 13 +++++++++++++ src/backend/utils/adt/selfuncs.c | 24 +++++++++++++++++++----- src/include/optimizer/pathnode.h | 1 + src/test/regress/expected/with.out | 18 ++++++++++++++++++ src/test/regress/sql/with.sql | 5 +++++ 5 files changed, 56 insertions(+), 5 deletions(-) diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c index 5a9ce44532..22d01cef5b 100644 --- a/src/backend/optimizer/util/relnode.c +++ b/src/backend/optimizer/util/relnode.c @@ -420,6 +420,19 @@ find_base_rel(PlannerInfo *root, int relid) return NULL; /* keep compiler quiet */ } +/* + * find_base_rel_noerr + * Find a base or otherrel relation entry, returning NULL if there's none + */ +RelOptInfo * +find_base_rel_noerr(PlannerInfo *root, int relid) +{ + /* use an unsigned comparison to prevent negative array element access */ + if ((uint32) relid < (uint32) root->simple_rel_array_size) + return root->simple_rel_array[relid]; + return NULL; +} + /* * find_base_rel_ignore_join * Find a base or otherrel relation entry, which must already exist. diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index dbcd98d985..cea777e9d4 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -119,6 +119,7 @@ #include "optimizer/paths.h" #include "optimizer/plancat.h" #include "parser/parse_clause.h" +#include "parser/parse_relation.h" #include "parser/parsetree.h" #include "statistics/statistics.h" #include "storage/bufmgr.h" @@ -5434,17 +5435,30 @@ examine_simple_variable(PlannerInfo *root, Var *var, if (HeapTupleIsValid(vardata->statsTuple)) { - RelOptInfo *onerel = find_base_rel(root, var->varno); + RelOptInfo *onerel = find_base_rel_noerr(root, var->varno); Oid userid; /* * Check if user has permission to read this column. We require * all rows to be accessible, so there must be no securityQuals - * from security barrier views or RLS policies. Use - * onerel->userid if it's set, in case we're accessing the table - * via a view. + * from security barrier views or RLS policies. + * + * Normally the Var will have an associated RelOptInfo from which + * we can find out which userid to do the check as; but it might + * not if it's a RETURNING Var for an INSERT target relation. In + * that case use the RTEPermissionInfo associated with the RTE. */ - userid = OidIsValid(onerel->userid) ? onerel->userid : GetUserId(); + if (onerel) + userid = onerel->userid; + else + { + RTEPermissionInfo *perminfo; + + perminfo = getRTEPermissionInfo(root->parse->rteperminfos, rte); + userid = perminfo->checkAsUser; + } + if (!OidIsValid(userid)) + userid = GetUserId(); vardata->acl_ok = rte->securityQuals == NIL && diff --git a/src/include/optimizer/pathnode.h b/src/include/optimizer/pathnode.h index 03a0e46e70..c43d97b48a 100644 --- a/src/include/optimizer/pathnode.h +++ b/src/include/optimizer/pathnode.h @@ -307,6 +307,7 @@ extern void expand_planner_arrays(PlannerInfo *root, int add_size); extern RelOptInfo *build_simple_rel(PlannerInfo *root, int relid, RelOptInfo *parent); extern RelOptInfo *find_base_rel(PlannerInfo *root, int relid); +extern RelOptInfo *find_base_rel_noerr(PlannerInfo *root, int relid); extern RelOptInfo *find_base_rel_ignore_join(PlannerInfo *root, int relid); extern RelOptInfo *find_join_rel(PlannerInfo *root, Relids relids); extern RelOptInfo *build_join_rel(PlannerInfo *root, diff --git a/src/test/regress/expected/with.out b/src/test/regress/expected/with.out index 69c56ce207..3cf969d938 100644 --- a/src/test/regress/expected/with.out +++ b/src/test/regress/expected/with.out @@ -654,6 +654,24 @@ select count(*) from tenk1 a -> CTE Scan on x (8 rows) +explain (costs off) +with x as materialized (insert into tenk1 default values returning unique1) +select count(*) from tenk1 a + where unique1 in (select * from x); + QUERY PLAN +------------------------------------------------------------ + Aggregate + CTE x + -> Insert on tenk1 + -> Result + -> Nested Loop + -> HashAggregate + Group Key: x.unique1 + -> CTE Scan on x + -> Index Only Scan using tenk1_unique1 on tenk1 a + Index Cond: (unique1 = x.unique1) +(10 rows) + -- SEARCH clause create temp table graph0( f int, t int, label text ); insert into graph0 values diff --git a/src/test/regress/sql/with.sql b/src/test/regress/sql/with.sql index 3ef9898866..ff68e21e2e 100644 --- a/src/test/regress/sql/with.sql +++ b/src/test/regress/sql/with.sql @@ -354,6 +354,11 @@ with x as materialized (select unique1 from tenk1 b) select count(*) from tenk1 a where unique1 in (select * from x); +explain (costs off) +with x as materialized (insert into tenk1 default values returning unique1) +select count(*) from tenk1 a + where unique1 in (select * from x); + -- SEARCH clause create temp table graph0( f int, t int, label text );