-> Parallel Seq Scan on p1_c3_c2
(25 rows)
--- seqscan doesn't harm parallelism
+-- Parallel sequential scan
/*+Parallel(p1 8 hard) SeqScan(p1) */
EXPLAIN (COSTS false) SELECT * FROM p1 join p2 on p1.id = p2.id;
LOG: pg_hint_plan:
-> Seq Scan on p2_c3_c2
(25 rows)
--- Index partial scan is not handled yet.
+-- Parallel index scan
/*+Parallel(p1 8 hard) IndexScan(p1) */
EXPLAIN (COSTS false) SELECT * FROM p1 join p2 on p1.id = p2.id;
LOG: pg_hint_plan:
duplication hint:
error hint:
- QUERY PLAN
---------------------------------------------------------
- Hash Join
- Hash Cond: (p1.id = p2.id)
- -> Append
- -> Index Scan using p1_pkey on p1
- -> Index Scan using p1_c1_pkey on p1_c1
- -> Index Scan using p1_c2_pkey on p1_c2
- -> Index Scan using p1_c3_pkey on p1_c3
- -> Index Scan using p1_c4_pkey on p1_c4
- -> Index Scan using p1_c1_c1_pkey on p1_c1_c1
- -> Index Scan using p1_c1_c2_pkey on p1_c1_c2
- -> Index Scan using p1_c3_c1_pkey on p1_c3_c1
- -> Index Scan using p1_c3_c2_pkey on p1_c3_c2
- -> Hash
+ QUERY PLAN
+-----------------------------------------------------------------------
+ Gather
+ Workers Planned: 8
+ -> Hash Join
+ Hash Cond: (p1.id = p2.id)
-> Append
- -> Seq Scan on p2
- -> Seq Scan on p2_c1
- -> Seq Scan on p2_c2
- -> Seq Scan on p2_c3
- -> Seq Scan on p2_c4
- -> Seq Scan on p2_c1_c1
- -> Seq Scan on p2_c1_c2
- -> Seq Scan on p2_c3_c1
- -> Seq Scan on p2_c3_c2
-(23 rows)
+ -> Parallel Index Scan using p1_pkey on p1
+ -> Parallel Index Scan using p1_c1_pkey on p1_c1
+ -> Parallel Index Scan using p1_c2_pkey on p1_c2
+ -> Parallel Index Scan using p1_c3_pkey on p1_c3
+ -> Parallel Index Scan using p1_c4_pkey on p1_c4
+ -> Parallel Index Scan using p1_c1_c1_pkey on p1_c1_c1
+ -> Parallel Index Scan using p1_c1_c2_pkey on p1_c1_c2
+ -> Parallel Index Scan using p1_c3_c1_pkey on p1_c3_c1
+ -> Parallel Index Scan using p1_c3_c2_pkey on p1_c3_c2
+ -> Hash
+ -> Append
+ -> Seq Scan on p2
+ -> Seq Scan on p2_c1
+ -> Seq Scan on p2_c2
+ -> Seq Scan on p2_c3
+ -> Seq Scan on p2_c4
+ -> Seq Scan on p2_c1_c1
+ -> Seq Scan on p2_c1_c2
+ -> Seq Scan on p2_c3_c1
+ -> Seq Scan on p2_c3_c2
+(25 rows)
-- This hint doesn't turn on parallel, so the Parallel hint is ignored
set max_parallel_workers_per_gather TO 0;