Re: pglz compression performance, take two

> 22 янв. 2021 г., в 07:48, Justin Pryzby <pryzby(at)telsasoft(dot)com> написал(а):
>
> @cfbot: rebased
> <0001-Reorganize-pglz-compression-code.patch>

Thanks!

I'm experimenting with TPC-C over PostgreSQL 13 on production-like cluster in the cloud. Overall performance is IO-bound, but compression is burning a lot energy too (according to perf top). Cluster consists of 3 nodes(only HA, no standby queries) with 32 vCPU each, 128GB RAM, sync replication, 2000 warehouses, 240GB PGDATA.

Samples: 1M of event 'cpu-clock', 4000 Hz, Event count (approx.): 177958545079
Overhead Shared Object Symbol
18.36% postgres [.] pglz_compress
3.88% [kernel] [k] _raw_spin_unlock_irqrestore
3.39% postgres [.] hash_search_with_hash_value
3.00% [kernel] [k] finish_task_switch
2.03% [kernel] [k] copy_user_enhanced_fast_string
1.14% [kernel] [k] filemap_map_pages
1.02% postgres [.] AllocSetAlloc
0.93% postgres [.] _bt_compare
0.89% postgres [.] PinBuffer
0.82% postgres [.] SearchCatCache1
0.79% postgres [.] LWLockAttemptLock
0.78% postgres [.] GetSnapshotData

Overall cluster runs 862tps (52KtpmC, though only 26KtmpC is qualified on 2K warehouses).

Thanks!

Best regards, Andrey Borodin.