postgres_fdw: Fix crash when pushing down multiple joins.

A join clause might mention multiple relations on either side, so it
need not be the case that a given joinrel's constituent relations are
all on one side of the join clause or all on the other.

Report by Rajkumar Raghuwanshi.  Analysis and fix by Michael Paquier
and Ashutosh Bapat.
This commit is contained in:
Robert Haas 2016-03-23 12:28:01 -04:00
parent 44ca4022f3
commit 3151f16e18
3 changed files with 289 additions and 4 deletions

View File

@ -987,6 +987,34 @@ SELECT t1.c1, t2.c1 FROM ft4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.
40 |
(10 rows)
-- left outer join three tables
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 LEFT JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
11 | 1 |
12 | 2 | AAA012
13 | 3 |
14 | 4 | AAA014
15 | 5 |
16 | 6 | AAA016
17 | 7 |
18 | 8 | AAA018
19 | 9 |
20 | 0 | AAA020
(10 rows)
-- left outer join + placement of clauses.
-- clauses within the nullable side are not pulled up, but top level clause on
-- non-nullable side is pushed into non-nullable side
@ -1060,6 +1088,34 @@ SELECT t1.c1, t2.c1 FROM ft5 t1 RIGHT JOIN ft4 t2 ON (t1.c1 = t2.c1) ORDER BY t2
| 40
(10 rows)
-- right outer join three tables
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft4 t3) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft2 t1)
Remote SQL: SELECT r4.c3, r2.c2, r1."C 1" FROM (("S 1"."T 3" r4 LEFT JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r4.c1)))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1"))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
22 | 2 | AAA022
24 | 4 | AAA024
26 | 6 | AAA026
28 | 8 | AAA028
30 | 0 | AAA030
32 | 2 | AAA032
34 | 4 | AAA034
36 | 6 | AAA036
38 | 8 | AAA038
40 | 0 | AAA040
(10 rows)
-- full outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
@ -1088,6 +1144,202 @@ SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.
| 27
(10 rows)
-- full outer join three tables
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) FULL JOIN (public.ft2 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
11 | 1 |
12 | 2 | AAA012
13 | 3 |
14 | 4 | AAA014
15 | 5 |
16 | 6 | AAA016
17 | 7 |
18 | 8 | AAA018
19 | 9 |
20 | 0 | AAA020
(10 rows)
-- full outer join + right outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft4 t3) LEFT JOIN (public.ft2 t2)) LEFT JOIN (public.ft2 t1)
Remote SQL: SELECT r4.c3, r2.c2, r1."C 1" FROM (("S 1"."T 3" r4 LEFT JOIN "S 1"."T 1" r2 ON (((r2."C 1" = r4.c1)))) LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1"))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
22 | 2 | AAA022
24 | 4 | AAA024
26 | 6 | AAA026
28 | 8 | AAA028
30 | 0 | AAA030
32 | 2 | AAA032
34 | 4 | AAA034
36 | 6 | AAA036
38 | 8 | AAA038
40 | 0 | AAA040
(10 rows)
-- right outer join + full outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t2) LEFT JOIN (public.ft2 t1)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r2.c2, r1."C 1", r4.c3 FROM (("S 1"."T 1" r2 LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
11 | 1 |
12 | 2 | AAA012
13 | 3 |
14 | 4 | AAA014
15 | 5 |
16 | 6 | AAA016
17 | 7 |
18 | 8 | AAA018
19 | 9 |
20 | 0 | AAA020
(10 rows)
-- full outer join + left outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) FULL JOIN (public.ft2 t2)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 FULL JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
11 | 1 |
12 | 2 | AAA012
13 | 3 |
14 | 4 | AAA014
15 | 5 |
16 | 6 | AAA016
17 | 7 |
18 | 8 | AAA018
19 | 9 |
20 | 0 | AAA020
(10 rows)
-- left outer join + full outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t1) LEFT JOIN (public.ft2 t2)) FULL JOIN (public.ft4 t3)
Remote SQL: SELECT r1."C 1", r2.c2, r4.c3 FROM (("S 1"."T 1" r1 LEFT JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) FULL JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
11 | 1 |
12 | 2 | AAA012
13 | 3 |
14 | 4 | AAA014
15 | 5 |
16 | 6 | AAA016
17 | 7 |
18 | 8 | AAA018
19 | 9 |
20 | 0 | AAA020
(10 rows)
-- right outer join + left outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: ((public.ft2 t2) LEFT JOIN (public.ft2 t1)) LEFT JOIN (public.ft4 t3)
Remote SQL: SELECT r2.c2, r1."C 1", r4.c3 FROM (("S 1"."T 1" r2 LEFT JOIN "S 1"."T 1" r1 ON (((r1."C 1" = r2."C 1")))) LEFT JOIN "S 1"."T 3" r4 ON (((r2."C 1" = r4.c1))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
11 | 1 |
12 | 2 | AAA012
13 | 3 |
14 | 4 | AAA014
15 | 5 |
16 | 6 | AAA016
17 | 7 |
18 | 8 | AAA018
19 | 9 |
20 | 0 | AAA020
(10 rows)
-- left outer join + right outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit
Output: t1.c1, t2.c2, t3.c3
-> Foreign Scan
Output: t1.c1, t2.c2, t3.c3
Relations: (public.ft4 t3) LEFT JOIN ((public.ft2 t1) INNER JOIN (public.ft2 t2))
Remote SQL: SELECT r4.c3, r1."C 1", r2.c2 FROM ("S 1"."T 3" r4 LEFT JOIN ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (TRUE)) ON (((r2."C 1" = r4.c1)) AND ((r1."C 1" = r2."C 1"))))
(6 rows)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
c1 | c2 | c3
----+----+--------
22 | 2 | AAA022
24 | 4 | AAA024
26 | 6 | AAA026
28 | 8 | AAA028
30 | 0 | AAA030
32 | 2 | AAA032
34 | 4 | AAA034
36 | 6 | AAA036
38 | 8 | AAA038
40 | 0 | AAA040
(10 rows)
-- full outer join + WHERE clause, only matched rows
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) WHERE (t1.c1 = t2.c1 OR t1.c1 IS NULL) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;

View File

@ -727,12 +727,9 @@ get_useful_ecs_for_relation(PlannerInfo *root, RelOptInfo *rel)
if (bms_is_subset(relids, restrictinfo->right_ec->ec_relids))
useful_eclass_list = list_append_unique_ptr(useful_eclass_list,
restrictinfo->right_ec);
else
{
Assert(bms_is_subset(relids, restrictinfo->left_ec->ec_relids));
else if (bms_is_subset(relids, restrictinfo->left_ec->ec_relids))
useful_eclass_list = list_append_unique_ptr(useful_eclass_list,
restrictinfo->left_ec);
}
}
return useful_eclass_list;

View File

@ -343,6 +343,10 @@ SELECT t1.c1, t2.c2, t3.c3 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) JOIN ft4 t
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c1 FROM ft4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c1 FROM ft4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
-- left outer join three tables
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- left outer join + placement of clauses.
-- clauses within the nullable side are not pulled up, but top level clause on
-- non-nullable side is pushed into non-nullable side
@ -360,10 +364,42 @@ SELECT t1.c1, t1.c2, t2.c1, t2.c2 FROM ft4 t1 LEFT JOIN (SELECT * FROM ft5 WHERE
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c1 FROM ft5 t1 RIGHT JOIN ft4 t2 ON (t1.c1 = t2.c1) ORDER BY t2.c1, t1.c1 OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c1 FROM ft5 t1 RIGHT JOIN ft4 t2 ON (t1.c1 = t2.c1) ORDER BY t2.c1, t1.c1 OFFSET 10 LIMIT 10;
-- right outer join three tables
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- full outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 45 LIMIT 10;
-- full outer join three tables
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- full outer join + right outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- right outer join + full outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- full outer join + left outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 FULL JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- left outer join + full outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) FULL JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- right outer join + left outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 RIGHT JOIN ft2 t2 ON (t1.c1 = t2.c1) LEFT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- left outer join + right outer join
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
SELECT t1.c1, t2.c2, t3.c3 FROM ft2 t1 LEFT JOIN ft2 t2 ON (t1.c1 = t2.c1) RIGHT JOIN ft4 t3 ON (t2.c1 = t3.c1) OFFSET 10 LIMIT 10;
-- full outer join + WHERE clause, only matched rows
EXPLAIN (COSTS false, VERBOSE)
SELECT t1.c1, t2.c1 FROM ft4 t1 FULL JOIN ft5 t2 ON (t1.c1 = t2.c1) WHERE (t1.c1 = t2.c1 OR t1.c1 IS NULL) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;