Re: Slow response from 'SELECT * FROM table'

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От Josh Berkus
Тема Re: Slow response from 'SELECT * FROM table'
Дата
Msg-id web-1821126@davinci.ethosmedia.com
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Ответ на Slow response from 'SELECT * FROM table'  (Jirka Novak <j.novak@netsystem.cz>)
Список pgsql-performance
Jirka,

>   I have table with 30 columns and 30000..500000 rows. When I make
> 'SELECT * FROM table' postgresql start doing something and return
> first row after 10s (for 30k rows) and after 5min (500k rows). It
> looks like it copy whole response to temp space and after that it
> shows it.
>   I don't know why. I tested same table structure and datas on Oracle
>
> and MSSQL and both returned first row immediatly.
>   Have someone any idea?

I can think of any number of reasons why.   However, I need more detail
from you:

1) Why are you selecting 500,000 rows at once?

2) Is "SELECT * FROM table_a" the entirety of your query, or was there
more to it than that?

3) Are you talking about PSQL, or some other interface?

-Josh Berkus



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