Remove the test case added by commit
fac1b470a, which never actually
worked to expose the problem it claimed to test. Replace it with
a case that does expose the problem, and also covers the SRF-not-
at-the-top deficiency repaired in
1aa8dad41.
Richard Guo, with some editorialization by me
Discussion: https://postgr.es/m/17564-
c7472c2f90ef2da3@postgresql.org
-> Function Scan on generate_series
(7 rows)
--- Disallow pushing down sort when pathkey is an SRF.
-explain (costs off) select unique1 from tenk1 order by unnest('{1,2}'::int[]);
- QUERY PLAN
--------------------------------------------------------------------------
- Sort
- Sort Key: (unnest('{1,2}'::integer[]))
- -> Gather
- Workers Planned: 2
- -> ProjectSet
- -> Parallel Index Only Scan using tenk1_unique1 on tenk1
-(6 rows)
-
-> Result
(16 rows)
+-- must disallow pushing sort below gather when pathkey contains an SRF
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT unnest(ARRAY[]::integer[]) + 1 AS pathkey
+ FROM tenk1 t1 JOIN tenk1 t2 ON TRUE
+ ORDER BY pathkey;
+ QUERY PLAN
+-----------------------------------------------------------------------------------------------------
+ Sort
+ Output: (((unnest('{}'::integer[])) + 1))
+ Sort Key: (((unnest('{}'::integer[])) + 1))
+ -> Result
+ Output: ((unnest('{}'::integer[])) + 1)
+ -> ProjectSet
+ Output: unnest('{}'::integer[])
+ -> Nested Loop
+ -> Gather
+ Workers Planned: 4
+ -> Parallel Index Only Scan using tenk1_hundred on public.tenk1 t1
+ -> Materialize
+ -> Gather
+ Workers Planned: 4
+ -> Parallel Index Only Scan using tenk1_hundred on public.tenk1 t2
+(15 rows)
+
-- test passing expanded-value representations to workers
CREATE FUNCTION make_some_array(int,int) returns int[] as
$$declare x int[];
explain (costs off) select sub.unique1, stringu1 || random()::text
from tenk1, lateral (select tenk1.unique1 from generate_series(1, 1000)) as sub
order by 1, 2;
--- Disallow pushing down sort when pathkey is an SRF.
-explain (costs off) select unique1 from tenk1 order by unnest('{1,2}'::int[]);
SELECT generate_series(1, two), array(select generate_series(1, two))
FROM tenk1 ORDER BY tenthous;
+-- must disallow pushing sort below gather when pathkey contains an SRF
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT unnest(ARRAY[]::integer[]) + 1 AS pathkey
+ FROM tenk1 t1 JOIN tenk1 t2 ON TRUE
+ ORDER BY pathkey;
+
-- test passing expanded-value representations to workers
CREATE FUNCTION make_some_array(int,int) returns int[] as
$$declare x int[];