On Thu, Sep 18, 2014 at 2:58 AM, Mkrtchyan, Tigran <tigran.mkrtch...@desy.de > 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
