Message-ID: <52537E14.4040401@hogranch.com>
Date: Mon, 07 Oct 2013 20:37:56 -0700
From: John R Pierce <pierce@hogranch.com>
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To: pgsql-general@postgresql.org
Subject: Re: postgreSQL query via JDBC in different OS taking different
 running time?
References: <1bf97f3.3e260.14195c01fd6.Coremail.aftabac@siat.ac.cn>
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On 10/7/2013 6:48 PM, Aftab Ahmed Chandio wrote:
> 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)

a single connection session will only use a single core at a time.

depending on the nature of this query, it may have been CPU or Disk IO 
bound, without knowing the query, the database schema, and the hardware 
specification of both systems, its impossible to guess.

first thing to do is run..

     explain analyze  ...your query here...;

on both platforms, and verify they are doing the same thing.


-- 
john r pierce                                      37N 122W
somewhere on the middle of the left coast


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