Всем привет ! коллеги, наткнулся на письмо в мэйл лист:
PG PERFORMANCE mail list We have found that queries through PgBouncer 1.7.2 (with transaction pooling) to local PostgreSQL are almost two times slower in 9.5.3 than in 9.4.8 on RHEL 6 hosts (all packages are updated to last versions). Meanwhile the problem can’t be reproduced i.e. on Ubuntu 14.04 (also fully-updated).

Here is how the results look like for 9.4, 9.5 and 9.6. All are built from latest commits on yesterday in
* REL9_4_STABLE (a0cc89a28141595d888d8aba43163d58a1578bfb),
* REL9_5_STABLE (e504d915bbf352ecfc4ed335af934e799bf01053),
* master (6ee7fb8244560b7a3f224784b8ad2351107fa55d).

All of them are build on the host where testing is done (with stock gcc versions). Sysctls, pgbouncer config and everything we found are the same, postgres configs are default, PGDATA is in tmpfs. All numbers are reproducible, they are stable between runs.

Shortly:

OS PostgreSQL version TPS Avg. latency
RHEL 6 9.4 44898 1.425 ms
RHEL 6 9.5 26199 2.443 ms
RHEL 6 9.6 43027 1.487 ms
Ubuntu 14.04 9.4 67458 0.949 ms
Ubuntu 14.04 9.5 64065 0.999 ms
Ubuntu 14.04 9.6 64350 0.995 ms

You could see that the difference between major versions on Ubuntu is not significant, but on RHEL 9.5 is 70% slower than 9.4 and 9.6.

проверил на centos 7, получил ту же картину :
OS PG TPS AVG latency
Centos 7 9.5.3 23.711023 168.421
Centos 7 9.5.3 26.609271 150.188
Centos 7 9.5.3 25.220044 158.416
Centos 7 9.5.3 25.598977 156.047
Centos 7 9.4.8 278.572191 14.077
Centos 7 9.4.8 247.237755 16.177
Centos 7 9.4.8 240.007524 16.276
Centos 7 9.4.8 237.862238 16.596

djeday84,
ох :)) не успел дописать..
Кто знает, когда можно ждать исправлений в 9.5 ?