Re: pglz compression performance, take two

[Andrey Borodin]

> 22 янв. 2021 г., в 07:48, Justin Pryzby <pry...@telsasoft.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.