> Did it actually use a parallel plan in your testing?
> When I ran these tests with the Parallel INSERT patch applied, it did
> not naturally choose a parallel plan for any of these cases.
Yes, these cases pick parallel plan naturally on my test environment.
postgres=# explain verbose insert into testscan select a from x where a<80000 or (a%2=0 and a>199900000);
QUERY PLAN
---------------------------------------------------------------------------------------------------
Gather (cost=4346.89..1281204.64 rows=81372 width=0)
Workers Planned: 4
-> Insert on public.testscan (cost=3346.89..1272067.44 rows=0 width=0)
-> Parallel Bitmap Heap Scan on public.x1 (cost=3346.89..1272067.44 rows=20343 width=8)
Output: x1.a, NULL::integer
Recheck Cond: ((x1.a < 80000) OR (x1.a > 199900000))
Filter: ((x1.a < 80000) OR (((x1.a % 2) = 0) AND (x1.a > 199900000)))
-> BitmapOr (cost=3346.89..3346.89 rows=178808 width=0)
-> Bitmap Index Scan on x1_a_idx (cost=0.00..1495.19 rows=80883 width=0)
Index Cond: (x1.a < 80000)
-> Bitmap Index Scan on x1_a_idx (cost=0.00..1811.01 rows=97925 width=0)
Index Cond: (x1.a > 199900000)
PSA is my postgresql.conf file, maybe you can have a look. Besides, I didn't do any parameters tuning in my test
session.
Regards,
Tang