On Mon, Oct 7, 2013 at 10:35 PM, Kevin Grittner <kgrittn@xxxxxxxxx> wrote: > Aftab Ahmed Chandio <aftabac@xxxxxxxxxx> wrote: > >> My query processes from JDBC (Java Program) to PostgreSQL. I use >> system time by invoking java function, I collect one time unit >> before the query statement perform and second after the execution >> of query statement. >> I found 85 ms time unit in DOS (win7) (laptop 4cores). both Java >> and PostgreSQL installed and invoked on the same machine, >> respectively. >> On the other hand, I use same process (separate installation) on >> linux on 8 cores physical machine with 2times greater then >> laptop. >> I found 150 ms. (which is a question for me because the time in >> Linux environment should give me half of the time taking on >> laptop) >> I also make same setting of postgresql.conf in the linux setup, >> which is available same in the win7 setup, because win7 setup >> gives better performance of the query. >> What do u suggest me, where I need to make performance tuning? >> which configuration setting must need to modify in the linux? >> * laptop RAM 4 GB and Linux machine 32 GB > > Given a little time, I could probably list 100 plausible reasons > that could be. For my part, load balancing a production system > between PostgreSQL on Windows and on Linux hitting identical > databases on identical hardware, I saw 30% better performance on > Linux. One sneaky way that windows tends to beat linux is that windows has a low precision high performance timer that linux does not have. This affects both java and postgres and particularly tends to show up when benchmarking with times. merlin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
