On Thu, Sep 18, 2014 at 2:58 AM, Mkrtchyan, Tigran <tigran.mkrtchyan@xxxxxxx> wrote:
Hi Folk,
I am trying to investigate some performance issues which we have with postgres
(a different topic by itself) and tried postgres.9.4beta2, with a hope that it
perform better.
Turned out that 9.4 is 2x slower than 9.3.5 on the same hardware.
Some technical details:
Host: rhel 6.5 2.6.32-431.23.3.el6.x86_64
256 GB RAM, 40 cores, Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz
2x160GB PCIe SSD DELL_P320h-MTFDGAL175SAH ( on one 9.3, on an other one 9.4 )
Why are the versions segregated that way? Are you sure they are configured identically?
postgres tweaks:
default_statistics_target = 100
wal_writer_delay = 10s
vacuum_cost_delay = 50
synchronous_commit = off
Are you sure that synchronous_commit is actually off on the 9.4 instance?
9.3.5:
# /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 60
...
0.035940 END;
9.4beta2:
...
0.957854 END;
Looks like IO.
Cheers,
Jeff
