From: Sean Davis <sdavis2@mail.nih.gov>
To: NSO <nso@fmf.vtu.lt>
Cc: pgsql-performance@postgresql.org
Subject: Re: Bytea poor performance
Date: Sat, 15 Oct 2005 10:08:20 -0400
Message-ID: <BF768594.10D2B%sdavis2@mail.nih.gov> (raw)
In-Reply-To: <17363.81.7.89.65.1129384809.squirrel@fmf.vtu.lt>
On 10/15/05 10:00 AM, "NSO" <nso@fmf.vtu.lt> wrote:
> Hello,
>
> How about some explain analyze output?
> Explain analyse select * from files where nr > 1450
>
> "Index Scan using pk on files (cost=0.00..3.67 rows=50 width=36)
> (actual time=0.000..0.000 rows=50 loops=1)"
I may not be understanding the output, but your actual time reports 0 for
the query. And the total runtime is 23 seconds?
Sean
>> On 10/15/05 9:20 AM, "NSO" <nso@fmf.vtu.lt> wrote:
>>
>>> Hello,
>>>
>>> I am trying to select form table with bytea field. And queries runs very
>>> slow.
>>> My table:
>>> CREATE TABLE files (file bytea, nr serial NOT NULL) WITH OIDS;
>>>
>>> Query:
>>> select * from files where nr > 1450
>>>
>>> (I have total 1500 records in it, every holds picture of 23kB size)
>>> Query runs very long:
>>> Total query runtime: 23625 ms.
>>> Data retrieval runtime: 266 ms.
>>> 50 rows retrieved.
>>>
>>> explain:
>>> Index Scan using pk on files (cost=0.00..3.67 rows=50 width=36)
>>> Index Cond: (nr > 1450)
>>>
>>> Is it possible to do something with it? or it is normal? Our server is
>>> fast, and all other tables work fine..
>>
>> How about some explain analyze output? Have you done a full vacuum
>> lately?
>> How about reindexing?
>>
>> Sean
>>
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 6: explain analyze is your friend
>>
>> --
>> This message has been scanned for viruses and
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>>
>>
>
>
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To: pgsql-performance@postgresql.org
Cc: sdavis2@mail.nih.gov, nso@fmf.vtu.lt
Subject: Re: Bytea poor performance
In-Reply-To: <BF768594.10D2B%sdavis2@mail.nih.gov>
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