Re: Statistical Analysis
| От | Andrew McMillan |
|---|---|
| Тема | Re: Statistical Analysis |
| Дата | |
| Msg-id | 397CAC44.6934EA0E@catalyst.net.nz обсуждение исходный текст |
| Ответ на | RE: Statistical Analysis ("Nathan Barnett" <nbarnett@cellularphones.com>) |
| Список | pgsql-general |
Nathan Barnett wrote:
>
> Stephan,
> The SORT is what I'm trying to avoid because I was using a group by to grab
> all the data in the groups that I needed, but it requires a sort to group by
> and this bottlenecked the query. I really just wanted to grab a sample of
> all the rows in the table and then perform the group by on the subset to
> avoid the overhead of sorting the whole table. My query has no where
> clauses and thus must sort through all of the data being analyzed. It then
> aggregates the data in a table that is then being used in the realtime
> queries. The analysis must be able to run every hour.
What about using random() in the WHERE clause?
Regards,
Andrew.
--
_____________________________________________________________________
Andrew McMillan, e-mail: Andrew@cat-it.co.nz
Catalyst IT Ltd, PO Box 10-225, Level 22, 105 The Terrace, Wellington
Me: +64 (21) 635 694, Fax: +64 (4) 499 5596, Office: +64 (4) 499 2267
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