Re: Need more speed from this.

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От Martín Marqués
Тема Re: Need more speed from this.
Дата
Msg-id 20011119212809.A98432AB3F@bugs.unl.edu.ar
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Ответ на Need more speed from this.  (Brian Avis <brian.avis@searhc.org>)
Список pgsql-general
On Lun 19 Nov 2001 18:06, you wrote:
> I hope someone can help me out with this.
>
> Postgres 7.1.3
> Solaris 2.8
>
> I have a table called system_data setup like this.
>
>      | server_id |  date  |  time  | data_type_id | data |
>      |___________|________|________|______________|______|
>      |
>      |     26    | a date | a time |     8        |  98  |
>
>      -----------------------------------------------------
>
>
> This table is indexed on server_id and data_type_id.
>
> It currently has about 674,456 rows and is growing on a daily
> basis.
>
> The problem is that selects from this table are really slow.
>
> For instance if I do this.
>
> SELECT AVG(data) FROM system_data
>         WHERE date BETWEEN CAST('2001-02-01' AS DATE)
>             AND CAST ('2001-02-28' AS DATE)
>         AND
>             server_id = 26
>         AND
>             data_type_id = 8;
>
> It will take several seconds to complete this select.
>
> I need this type of data retrieval to be much faster if
> possible.

have you tried adding an index on the date column? It should make the
condition 'date between ...' much faster.

Saludos... :-)

--
Porqué usar una base de datos relacional cualquiera,
si podés usar PostgreSQL?
-----------------------------------------------------------------
Martín Marqués                  |        mmarques@unl.edu.ar
Programador, Administrador, DBA |       Centro de Telematica
                       Universidad Nacional
                            del Litoral
-----------------------------------------------------------------

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