Re: Performance issues when the number of records are around 10 Million - Mailing list pgsql-general

From Brian Modra
Subject Re: Performance issues when the number of records are around 10 Million
Date
Msg-id AANLkTikv9nF2Tp8tTF5ddVcCudDFZNXszOAz4XW3kTGo@mail.gmail.com
Whole thread Raw
In response to Re: Performance issues when the number of records are around 10 Million  (Sergey Konoplev <gray.ru@gmail.com>)
List pgsql-general
On 11/05/2010, Sergey Konoplev <gray.ru@gmail.com> wrote:
> On 11 May 2010 10:18, venu madhav <venutaurus539@gmail.com> wrote:
>> select e.cid, timestamp, s.sig_class, s.sig_priority, s.sig_name,
>> e.sniff_ip, e.sniff_channel, s.sig_config, e.wifi_addr_1,
>> e.wifi_addr_2, e.view_status, bssid  FROM event e, signature s WHERE
>> s.sig_id = e.signature   AND e.timestamp >= '1270449180' AND
>> e.timestamp < '1273473180'  ORDER BY e.cid DESC,  e.cid DESC limit 21
>> offset 10539780;
>>
>> Can any one suggest me a better solution to improve the performance.
>> Please let me know if you've any further queries.
>
> 1. Avoid using large OFFSETs. Do instead "... ORDER BY e.cid, e.cid LIMIT
> 21;"
> 2. What "EXPLAIN SELECT ..." shows?
> 3. What "\d event" prints?
>
> --
> Sergey Konoplev
>
> Blog: http://gray-hemp.blogspot.com /
> Linkedin: http://ru.linkedin.com/in/grayhemp /
> JID/GTalk: gray.ru@gmail.com / Skype: gray-hemp / ICQ: 29353802
>
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Have you checked if the indexes don't have lots of dead references?
Try to create new indexes, and then delete the old indexes (or just
use reindex if this is not an online database in production).

--
Brian Modra   Land line: +27 23 5411 462
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