DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com;
	h=received:message-id:date:from:user-agent:x-accept-language:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding;
	b=GFbt8OQVq+Jl1I1zSslBa7/hYuxm3Dbt4kMm+VQsEz+aw2e53UvinL4G8HNvR+lJNix0dagz6tq1yOUdukjURIVoJu4Zc3dsPmrLwXljHkxHHkQSBp1x7QR6abBRMnVlBIkFQy0wF9z1bzGRf9DIyTlGo96YhMvfm+Uow8an/nw=
Message-ID: <43FA5D20.2080805@gmail.com>
Date: Tue, 21 Feb 2006 11:21:52 +1100
From: Chris <dmagick@gmail.com>
User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923)
MIME-Version: 1.0
To: Marcos <mjs_ops@gmx.net>
CC: pgsql-performance@postgresql.org
Subject: Re: Creating a correct and real benchmark
References: <1140432636.1170.6.camel@servidor> <op.s5aqydincigqcu@apollo13>
In-Reply-To: <op.s5aqydincigqcu@apollo13>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

PFC wrote:
> 
>> I'm developing a search engine using the postgresql's databas. I've
>> already doing some tunnings looking increase the perform.
>>
>> Now, I'd like of do a realistic test of perfom with number X of queries
>> for know the performance with many queries.
>>
>> What the corret way to do this?
> 
> 
> 
>     I guess the only way to know how it will perform with your own  
> application is to benchmark it with queries coming from your own  
> application. You can create a test suite with a number of typical 
> queries  and use your favourite scripting language to spawn a number of 
> threads and  hammer the database. I find it interesting to measure the 
> responsiveness  of the server while torturing it, simply by measuring 
> the time it takes to  respond to a simple query and graphing it. Also 
> you should not have N  threads issue the exact same queries, because 
> then you will hit a too  small dataset. Introduce some randomness in the 
> testing, for instance.  Benchmarking from another machine makes sure the 
> test client's CPU usage  is not a part of the problem.

The other advice on top of this is don't just import a small amount of data.

If your application is going to end up with 200,000 rows - then test 
with 200,000 rows or more so you know exactly how it will handle under 
"production" conditions.