Re: Cache Hash Index meta page.

On Thu, Dec 1, 2016 at 8:10 PM, Jesper Pedersen <jesper(dot)pedersen(at)redhat(dot)com>
wrote:
>As the concurrent hash index patch was committed in 6d46f4 this patch
needs a rebase.

Thanks Jesper,

Adding the rebased patch.

I have re-run the pgbench readonly tests with below modification.

"alter table pgbench_accounts drop constraint pgbench_accounts_pkey"
postgres
"create index pgbench_accounts_pkey on pgbench_accounts using hash(aid)"
postgres

*Postgres Server settings:*
./postgres -c shared_buffers=8GB -N 200 -c min_wal_size=15GB -c
max_wal_size=20GB -c checkpoint_timeout=900 -c maintenance_work_mem=1GB -c
checkpoint_completion_target=0.9

*pgbench settings:*
scale_factor = 300 (so database fits in shared_buffer)
Mode = -M prepared -S (prepared readonly mode).

Machine used:
power2 with sufficient ram for above shared_buffer.

#############lscpu
CPU(s): 192
On-line CPU(s) list: 0-191
Thread(s) per core: 8
Core(s) per socket: 1
Socket(s): 24
NUMA node(s): 4
Model: IBM,8286-42A

*Clients *

*Cache Meta Page patch *

*Base code with amits changes*

* %imp*

1

17062.513102

17218.353817

-0.9050848685

8

138525.808342

128149.381759

8.0971335488

16

212278.44762

205870.456661

3.1126326054

32

369453.224112

360423.566937

2.5052904425

*64*

*576090.293018*

*510665.044842*

*12.8117733604*

*96*

*686813.187117*

*504950.885867*

*36.0158396272*

*104*

*688932.67516*

*498365.55841*

*38.2384202789*

*128*

*730728.526322*

*409011.008553*

*78.6574226711*

Appears there is a good improvement at higher clients.

--
Thanks and Regards
Mithun C Y
EnterpriseDB: http://www.enterprisedb.com