diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index 7992191f79d55e13f910bf270b1b3af1d733f275..a75462b02afbf9f588d6bb7c782e6fb92d863907 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -254,6 +254,18 @@ foreign_expr_walker(Node *node,
var->varlevelsup == 0)
{
/* Var belongs to foreign table */
+
+ /*
+ * System columns other than ctid should not be sent to
+ * the remote, since we don't make any effort to ensure
+ * that local and remote values match (tableoid, in
+ * particular, almost certainly doesn't match).
+ */
+ if (var->varattno < 0 &&
+ var->varattno != SelfItemPointerAttributeNumber)
+ return false;
+
+ /* Else check the collation */
collation = var->varcollid;
state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
}
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index f7e11edab1234debdc2b7fac1e1dd05a63dd5c80..c7ba042cb7fca0d16208620825338f7bc8735adf 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -832,6 +832,74 @@ DEALLOCATE st2;
DEALLOCATE st3;
DEALLOCATE st4;
DEALLOCATE st5;
+-- System columns, except ctid, should not be sent to remote
+EXPLAIN (VERBOSE, COSTS false)
+SELECT * FROM ft1 t1 WHERE t1.tableoid = 'pg_class'::regclass LIMIT 1;
+ QUERY PLAN
+-------------------------------------------------------------------------------
+ Limit
+ Output: c1, c2, c3, c4, c5, c6, c7, c8
+ -> Foreign Scan on public.ft1 t1
+ Output: c1, c2, c3, c4, c5, c6, c7, c8
+ Filter: (t1.tableoid = 1259::oid)
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1"
+(6 rows)
+
+SELECT * FROM ft1 t1 WHERE t1.tableoid = 'ft1'::regclass LIMIT 1;
+ c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+----+----+-------+------------------------------+--------------------------+----+------------+-----
+ 1 | 1 | 00001 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
+(1 row)
+
+EXPLAIN (VERBOSE, COSTS false)
+SELECT tableoid::regclass, * FROM ft1 t1 LIMIT 1;
+ QUERY PLAN
+-------------------------------------------------------------------------------
+ Limit
+ Output: ((tableoid)::regclass), c1, c2, c3, c4, c5, c6, c7, c8
+ -> Foreign Scan on public.ft1 t1
+ Output: (tableoid)::regclass, c1, c2, c3, c4, c5, c6, c7, c8
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1"
+(5 rows)
+
+SELECT tableoid::regclass, * FROM ft1 t1 LIMIT 1;
+ tableoid | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+----------+----+----+-------+------------------------------+--------------------------+----+------------+-----
+ ft1 | 1 | 1 | 00001 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
+(1 row)
+
+EXPLAIN (VERBOSE, COSTS false)
+SELECT * FROM ft1 t1 WHERE t1.ctid = '(0,2)';
+ QUERY PLAN
+-------------------------------------------------------------------------------------------------------
+ Foreign Scan on public.ft1 t1
+ Output: c1, c2, c3, c4, c5, c6, c7, c8
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE ((ctid = '(0,2)'::tid))
+(3 rows)
+
+SELECT * FROM ft1 t1 WHERE t1.ctid = '(0,2)';
+ c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+----+----+-------+------------------------------+--------------------------+----+------------+-----
+ 2 | 2 | 00002 | Sat Jan 03 00:00:00 1970 PST | Sat Jan 03 00:00:00 1970 | 2 | 2 | foo
+(1 row)
+
+EXPLAIN (VERBOSE, COSTS false)
+SELECT ctid, * FROM ft1 t1 LIMIT 1;
+ QUERY PLAN
+-------------------------------------------------------------------------------------
+ Limit
+ Output: ctid, c1, c2, c3, c4, c5, c6, c7, c8
+ -> Foreign Scan on public.ft1 t1
+ Output: ctid, c1, c2, c3, c4, c5, c6, c7, c8
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8, ctid FROM "S 1"."T 1"
+(5 rows)
+
+SELECT ctid, * FROM ft1 t1 LIMIT 1;
+ ctid | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+-------+----+----+-------+------------------------------+--------------------------+----+------------+-----
+ (0,1) | 1 | 1 | 00001 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
+(1 row)
+
-- ===================================================================
-- used in pl/pgsql function
-- ===================================================================
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index ae9668463c4a7f0a5064873b0c2b4d77a35e0d28..01491f886c1a3b023b3013148a95d2e2f250693b 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -254,6 +254,20 @@ DEALLOCATE st3;
DEALLOCATE st4;
DEALLOCATE st5;
+-- System columns, except ctid, should not be sent to remote
+EXPLAIN (VERBOSE, COSTS false)
+SELECT * FROM ft1 t1 WHERE t1.tableoid = 'pg_class'::regclass LIMIT 1;
+SELECT * FROM ft1 t1 WHERE t1.tableoid = 'ft1'::regclass LIMIT 1;
+EXPLAIN (VERBOSE, COSTS false)
+SELECT tableoid::regclass, * FROM ft1 t1 LIMIT 1;
+SELECT tableoid::regclass, * FROM ft1 t1 LIMIT 1;
+EXPLAIN (VERBOSE, COSTS false)
+SELECT * FROM ft1 t1 WHERE t1.ctid = '(0,2)';
+SELECT * FROM ft1 t1 WHERE t1.ctid = '(0,2)';
+EXPLAIN (VERBOSE, COSTS false)
+SELECT ctid, * FROM ft1 t1 LIMIT 1;
+SELECT ctid, * FROM ft1 t1 LIMIT 1;
+
-- ===================================================================
-- used in pl/pgsql function
-- ===================================================================
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index fa478025c1ad55483b9f10b25ab33a3edb5d128a..bf8dbe09db5f2b3f278dd85186e2051d60f69401 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -20,6 +20,7 @@
#include <math.h>
#include "access/skey.h"
+#include "access/sysattr.h"
#include "catalog/pg_class.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
@@ -1957,6 +1958,8 @@ create_foreignscan_plan(PlannerInfo *root, ForeignPath *best_path,
RelOptInfo *rel = best_path->path.parent;
Index scan_relid = rel->relid;
RangeTblEntry *rte;
+ Bitmapset *attrs_used = NULL;
+ ListCell *lc;
int i;
/* it should be a base rel... */
@@ -2004,17 +2007,34 @@ create_foreignscan_plan(PlannerInfo *root, ForeignPath *best_path,
* Detect whether any system columns are requested from rel. This is a
* bit of a kluge and might go away someday, so we intentionally leave it
* out of the API presented to FDWs.
+ *
+ * First, examine all the attributes needed for joins or final output.
+ * Note: we must look at reltargetlist, not the attr_needed data, because
+ * attr_needed isn't computed for inheritance child rels.
*/
+ pull_varattnos((Node *) rel->reltargetlist, rel->relid, &attrs_used);
+
+ /* Add all the attributes used by restriction clauses. */
+ foreach(lc, rel->baserestrictinfo)
+ {
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
+
+ pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
+ }
+
+ /* Now, are any system columns requested from rel? */
scan_plan->fsSystemCol = false;
- for (i = rel->min_attr; i < 0; i++)
+ for (i = FirstLowInvalidHeapAttributeNumber + 1; i < 0; i++)
{
- if (!bms_is_empty(rel->attr_needed[i - rel->min_attr]))
+ if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber, attrs_used))
{
scan_plan->fsSystemCol = true;
break;
}
}
+ bms_free(attrs_used);
+
return scan_plan;
}