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From: Richard Huxton <dev@archonet.com>
To: msmbarabino@virgilio.it <msmbarabino@virgilio.it>
Cc: pgsql-performance@postgresql.org
Subject: Re: R: Very slow bytea data extraction
Date: Fri, 23 Feb 2007 14:39:21 +0000
Message-ID: <45DEFC99.4070408@archonet.com> (raw)
In-Reply-To: <110ee8b13e5.msmbarabino@virgilio.it>
References: <110ee8b13e5.msmbarabino@virgilio.it>

msmbarabino@virgilio.it wrote:
> Thanks for your reply,
> 
> 
>> Is it in executing the query (what does 
> EXPLAIN ANALYSE show)?
> 
> Here is the output of explain analyze SELECT * 
> FROM "FILE"
> 
> "Seq Scan on "FILE"  (cost=0.00..1.36 rows=36 width=235) 
> (actual time=0.023..0.107 rows=36 loops=1)"

If you look at the "actual time" it's completing very quickly indeed. So 
- it must be something to do with either:
1. Fetching/formatting the data
2. Transferring the data to the client.

What happens if you only select half the rows? Does the time to run the 
select halve?

-- 
   Richard Huxton
   Archonet Ltd



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