--
-- 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_table_scan_size=0;
set max_parallel_workers_per_gather=4;
explain (costs off)
  select count(*) from a_star;
                        QUERY PLAN                         
-----------------------------------------------------------
 Finalize Aggregate
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  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
(12 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                           
---------------------------------------------------------------
 Remote Subquery Scan on all (datanode_1,datanode_2)
   Output: parallel_restricted(unique1)
   Sort Key: parallel_restricted(tenk1.unique1)
   ->  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)
(12 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)
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather
               Workers Planned: 4
               ->  Partial HashAggregate
                     Group Key: length((stringu1)::text)
                     ->  Parallel Seq Scan on tenk1
(8 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                         
-----------------------------------------------------------
 Finalize GroupAggregate
   Group Key: stringu1
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Sort
               Sort Key: stringu1
               ->  Partial HashAggregate
                     Group Key: stringu1
                     ->  Gather
                           Workers Planned: 4
                           ->  Parallel Seq Scan on tenk1
(10 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)
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather
               Workers Planned: 4
               ->  Parallel Index Only Scan using tenk1_unique1 on tenk1
(6 rows)

-- test parallel plans for queries containing un-correlated subplans.
alter table tenk2 set (parallel_workers = 0);
explain (costs off)
	select count(*) from tenk1 where (two, four) not in
	(select hundred, thousand from tenk2 where thousand > 100);
                                     QUERY PLAN                                      
-------------------------------------------------------------------------------------
 Finalize Aggregate
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather
               Workers Planned: 4
               ->  Partial Aggregate
                     ->  Parallel Seq Scan on tenk1
                           Filter: (NOT (hashed SubPlan 1))
                           SubPlan 1
                             ->  Remote Subquery Scan on all (datanode_1,datanode_2)
                                   ->  Seq Scan on tenk2
                                         Filter: (thousand > 100)
(11 rows)

select count(*) from tenk1 where (two, four) not in
	(select hundred, thousand from tenk2 where thousand > 100);
 count 
-------
 10000
(1 row)

-- this is not parallel-safe due to use of random() within SubLink's testexpr:
explain (costs off)
	select * from tenk1 where (unique1 + random())::integer not in
	(select ten from tenk2);
                            QUERY PLAN                             
-------------------------------------------------------------------
 Remote Subquery Scan on all (datanode_1,datanode_2)
   ->  Seq Scan on tenk1
         Filter: (NOT (hashed SubPlan 1))
         SubPlan 1
           ->  Remote Subquery Scan on all (datanode_1,datanode_2)
                 ->  Seq Scan on tenk2
(6 rows)

alter table tenk2 reset (parallel_workers);
-- test parallel index scans.
set enable_seqscan to off;
set enable_bitmapscan to off;
explain (costs off)
	select  count((unique1)) from tenk1 where hundred > 1;
                                QUERY PLAN                                
--------------------------------------------------------------------------
 Finalize Aggregate
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather
               Workers Planned: 4
               ->  Partial Aggregate
                     ->  Parallel Index Scan using tenk1_hundred on tenk1
                           Index Cond: (hundred > 1)
(7 rows)

select  count((unique1)) from tenk1 where hundred > 1;
 count 
-------
  9800
(1 row)

-- test parallel index-only scans.
explain (costs off)
	select  count(*) from tenk1 where thousand > 95;
                                      QUERY PLAN                                      
--------------------------------------------------------------------------------------
 Finalize Aggregate
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather
               Workers Planned: 4
               ->  Partial Aggregate
                     ->  Parallel Index Only Scan using tenk1_thous_tenthous on tenk1
                           Index Cond: (thousand > 95)
(7 rows)

select  count(*) from tenk1 where thousand > 95;
 count 
-------
  9040
(1 row)

reset enable_seqscan;
reset enable_bitmapscan;
-- test parallel bitmap heap scan.
set enable_seqscan to off;
set enable_indexscan to off;
set enable_hashjoin to off;
set enable_mergejoin to off;
set enable_material to off;
-- test prefetching, if the platform allows it
--DO $$
--BEGIN
-- SET effective_io_concurrency = 50;
--END $$;
set work_mem='64kB';  --set small work mem to force lossy pages
explain (costs off)
	select count(*) from tenk1, tenk2 where tenk1.hundred > 1 and tenk2.thousand=0;
                               QUERY PLAN                               
------------------------------------------------------------------------
 Aggregate
   ->  Nested Loop
         ->  Remote Subquery Scan on all (datanode_1,datanode_2)
               ->  Seq Scan on tenk2
                     Filter: (thousand = 0)
         ->  Materialize
               ->  Remote Subquery Scan on all (datanode_1,datanode_2)
                     ->  Gather
                           Workers Planned: 4
                           ->  Parallel Bitmap Heap Scan on tenk1
                                 Recheck Cond: (hundred > 1)
                                 ->  Bitmap Index Scan on tenk1_hundred
                                       Index Cond: (hundred > 1)
(13 rows)

select count(*) from tenk1, tenk2 where tenk1.hundred > 1 and tenk2.thousand=0;
 count 
-------
 98000
(1 row)

create table bmscantest (a int, t text);
insert into bmscantest select r, 'fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo' FROM generate_series(1,100000) r;
create index i_bmtest ON bmscantest(a);
select count(*) from bmscantest where a>1;
 count 
-------
 99999
(1 row)

reset enable_seqscan;
reset enable_indexscan;
reset enable_hashjoin;
reset enable_mergejoin;
reset enable_material;
reset effective_io_concurrency;
reset work_mem;
drop table bmscantest;
-- test parallel merge join path.
set enable_hashjoin to off;
set enable_nestloop to off;
explain (costs off)
	select  count(*) from tenk1, tenk2 where tenk1.unique1 = tenk2.unique1;
                                     QUERY PLAN                                      
-------------------------------------------------------------------------------------
 Finalize Aggregate
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather
               Workers Planned: 4
               ->  Partial Aggregate
                     ->  Merge Join
                           Merge Cond: (tenk1.unique1 = tenk2.unique1)
                           ->  Parallel Index Only Scan using tenk1_unique1 on tenk1
                           ->  Index Only Scan using tenk2_unique1 on tenk2
(9 rows)

select  count(*) from tenk1, tenk2 where tenk1.unique1 = tenk2.unique1;
 count 
-------
 10000
(1 row)

reset enable_hashjoin;
reset enable_nestloop;
--test gather merge
set enable_hashagg to off;
explain (costs off)
   select  string4, count((unique2)) from tenk1 group by string4 order by string4;
                        QUERY PLAN                         
-----------------------------------------------------------
 Finalize GroupAggregate
   Group Key: string4
   ->  Remote Subquery Scan on all (datanode_1,datanode_2)
         ->  Gather Merge
               Workers Planned: 4
               ->  Partial GroupAggregate
                     Group Key: string4
                     ->  Sort
                           Sort Key: string4
                           ->  Parallel Seq Scan on tenk1
(10 rows)

select  string4, count((unique2)) from tenk1 group by string4 order by string4;
 string4 | count 
---------+-------
 AAAAxx  |  2500
 HHHHxx  |  2500
 OOOOxx  |  2500
 VVVVxx  |  2500
(4 rows)

reset enable_hashagg;
set force_parallel_mode=1;
explain (costs off)
  select stringu1::int2 from tenk1 where unique1 = 1;
                     QUERY PLAN                      
-----------------------------------------------------
 Remote Fast Query Execution
   Node/s: datanode_1
   ->  Gather
         Workers Planned: 1
         Single Copy: true
         ->  Index Scan using tenk1_unique1 on tenk1
               Index Cond: (unique1 = 1)
(7 rows)

-- to increase the parallel query test coverage
EXPLAIN (timing off, summary off, costs off) SELECT * FROM tenk1;
               QUERY PLAN               
----------------------------------------
 Remote Fast Query Execution
   Node/s: datanode_1, datanode_2
   ->  Gather
         Workers Planned: 4
         ->  Parallel Seq Scan on tenk1
(5 rows)

EXPLAIN (analyze, timing off, summary off, costs off) SELECT * FROM tenk1;
                       QUERY PLAN                        
---------------------------------------------------------
 Remote Fast Query Execution (actual rows=10000 loops=1)
   Node/s: datanode_1, datanode_2
(2 rows)

-- provoke error in worker
select stringu1::int2 from tenk1 where unique1 = 1;
ERROR:  invalid input syntax for integer: "BAAAAA"
CONTEXT:  parallel worker
rollback;