Message-ID: <5104C570.2030001@richardneill.org>
Date: Sun, 27 Jan 2013 06:13:04 +0000
From: Richard Neill <rn214@richardneill.org>
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To: "ktm@rice.edu" <ktm@rice.edu>
CC: belal hamed <belalhamed@gmail.com>, pgsql-performance@postgresql.org
Subject: Re: PostgreSQL over internet
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	<20130127024505.GA12423@aart.rice.edu>
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On 27/01/13 02:45, ktm@rice.edu wrote:
> On Sun, Jan 27, 2013 at 03:15:45AM +0300, belal hamed wrote:
>>
>> I connect to my server through ADSL connection 4Mbps
>>
>
> Here is your "problem". You need to understand the performance
> characteristics of your communication channel. ADSL is a VERY
> asymmetric communications channel. Down is usually much faster
> than up.

I'm not convinced that ADSL is your problem.

1. Try just SSH directly to the server, and run psql, and run a query 
like this one:
    SELECT 'This is a test message' AS status;

This  should run in under 1ms; it also means that we don't have to worry 
about the details of your database-schema for the purposes of this problem.

2. Try creating a simple SSH tunnel and using your application locally. 
For example, if your server runs Postgresql on port 5432, run this SSH 
command:
   ssh -L 5432:localhost:5432 your_server_hostname
and then connect to your LOCAL (localhost) port 5432; SSH will handle 
the port forwarding.  [Explanation: "localhost" in the SSH command is in 
the context of your_server_hostname]
How does it work now?

3. Try configuration you are currently using, but with the above query.

It should be possible to distinguish between:
   - slowness caused by the database query itself
   - slowness caused by the network fundamentally.
   - slowness caused by the postgresql/libpq.

Hopefully, you'll be able to narrow it down a bit.

HTH,

Richard


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