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Re: Low CPU Usage

From: brauagustin-susc(at)yahoo(dot)com(dot)ar
To: Bill Moran <wmoran(at)collaborativefusion(dot)com>
Cc: Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Low CPU Usage
Date: 2007-09-21 19:01:34
Message-ID: 863435.2406.qm@web30014.mail.mud.yahoo.com (view raw or flat)
Thread:
Lists: pgsql-performance
>> > That's not what it looks like based on the EXPLAIN ANALYZE output.
>> > It looks like run time dropped from two seconds to half a second.
>>  
>> > It seems as though you either have a network delay delivering the results,
>> > or your application is slow to read them.
>> 
>> > Exactly how are you arriving at those timings you're reporting to us?
>>  
>> I have noticed this in a daly process I run which involves normally 45 minutes and with the new server takes 1:40.
>> 
>> Some days ago I began to do some tests with no success, then I opened PgAdmin with this simply query to read 2 big tables and then compare disk access.
>> SELECT *
>> FROM fact_ven_renta fvr, dim_producto_std_producto dpp
>> WHERE
>>   fvr.producto_std_producto_sk = dpp.producto_sk
>>  
>> fact_ven_renta has 136316 rows
>> dim_producto_std_producto has 3669 rows

>Run the tests from psql on the same server.  As Kevin pointed out, the _server_ is faster, but it appears as if the connection between PGadmin and this new server is slower somehow.

It runs quickly!!! But I don't know how to compare because looks like it retrieve fields by demand, when I put ctrl+end (go to the last record) it use a lot of CPU and disk, run quickly anyway.
Correct me if am I wrong but, executing PgAdmin in the same server there aren't networks delays!
And when the server is processing the query there isn't network traffic because is processing the result.

> Are you sure of your speed/duplex settings on the network side?  That's
> the most common cause of this kind of thing in my experience.  Try doing
> a raw FTP transfer between the client and server and see if you get the
> speed you should.
This isn't a dedicated database server, client application and server are running in the same machine!!!
I have stop the client application too with same results.

Anyway I will do some network test to find a solution.








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Subject: Re: Low CPU Usage
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