--
-- PARALLEL
--
create or replace function parallel_restricted(int) returns int as
  $$begin return $1; end$$ language plpgsql parallel restricted;
-- Serializable isolation would disable parallel query, so explicitly use an
-- arbitrary other level.
begin isolation level repeatable read;
-- encourage use of parallel plans
set parallel_setup_cost=0;
set parallel_tuple_cost=0;
set min_parallel_relation_size=0;
set max_parallel_workers_per_gather=4;
explain (costs off)
  select count(*) from a_star;
                     QUERY PLAN                      
-----------------------------------------------------
 Finalize Aggregate
   ->  Gather
         Workers Planned: 1
         ->  Partial Aggregate
               ->  Append
                     ->  Parallel Seq Scan on a_star
                     ->  Parallel Seq Scan on b_star
                     ->  Parallel Seq Scan on c_star
                     ->  Parallel Seq Scan on d_star
                     ->  Parallel Seq Scan on e_star
                     ->  Parallel Seq Scan on f_star
(11 rows)

select count(*) from a_star;
 count 
-------
    50
(1 row)

-- test that parallel_restricted function doesn't run in worker
alter table tenk1 set (parallel_workers = 4);
explain (verbose, costs off)
select parallel_restricted(unique1) from tenk1
  where stringu1 = 'GRAAAA' order by 1;
                       QUERY PLAN                        
---------------------------------------------------------
 Sort
   Output: (parallel_restricted(unique1))
   Sort Key: (parallel_restricted(tenk1.unique1))
   ->  Gather
         Output: parallel_restricted(unique1)
         Workers Planned: 4
         ->  Parallel Seq Scan on public.tenk1
               Output: unique1
               Filter: (tenk1.stringu1 = 'GRAAAA'::name)
(9 rows)

-- test parallel plan when group by expression is in target list.
explain (costs off)
	select length(stringu1) from tenk1 group by length(stringu1);
                    QUERY PLAN                     
---------------------------------------------------
 Finalize HashAggregate
   Group Key: (length((stringu1)::text))
   ->  Gather
         Workers Planned: 4
         ->  Partial HashAggregate
               Group Key: length((stringu1)::text)
               ->  Parallel Seq Scan on tenk1
(7 rows)

select length(stringu1) from tenk1 group by length(stringu1);
 length 
--------
      6
(1 row)

explain (costs off)
	select stringu1, count(*) from tenk1 group by stringu1 order by stringu1;
                     QUERY PLAN                     
----------------------------------------------------
 Sort
   Sort Key: stringu1
   ->  Finalize HashAggregate
         Group Key: stringu1
         ->  Gather
               Workers Planned: 4
               ->  Partial HashAggregate
                     Group Key: stringu1
                     ->  Parallel Seq Scan on tenk1
(9 rows)

-- test that parallel plan for aggregates is not selected when
-- target list contains parallel restricted clause.
explain (costs off)
	select  sum(parallel_restricted(unique1)) from tenk1
	group by(parallel_restricted(unique1));
                     QUERY PLAN                     
----------------------------------------------------
 HashAggregate
   Group Key: parallel_restricted(unique1)
   ->  Index Only Scan using tenk1_unique1 on tenk1
(3 rows)

set force_parallel_mode=1;
explain (costs off)
  select stringu1::int2 from tenk1 where unique1 = 1;
                  QUERY PLAN                   
-----------------------------------------------
 Gather
   Workers Planned: 1
   Single Copy: true
   ->  Index Scan using tenk1_unique1 on tenk1
         Index Cond: (unique1 = 1)
(5 rows)

do $$begin
  -- Provoke error, possibly in worker.  If this error happens to occur in
  -- the worker, there will be a CONTEXT line which must be hidden.
  perform stringu1::int2 from tenk1 where unique1 = 1;
  exception
	when others then
		raise 'SQLERRM: %', sqlerrm;
end$$;
ERROR:  SQLERRM: invalid input syntax for integer: "BAAAAA"
CONTEXT:  PL/pgSQL function inline_code_block line 7 at RAISE
rollback;