Re: Very high effective_cache_size == worse performance?

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От Kevin Grittner
Тема Re: Very high effective_cache_size == worse performance?
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Msg-id 4BCDA94E0200002500030BF8@gw.wicourts.gov
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Ответ на Re: Very high effective_cache_size == worse performance?  (David Kerr <dmk@mr-paradox.net>)
Ответы Re: Very high effective_cache_size == worse performance?  (David Kerr <dmk@mr-paradox.net>)
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David Kerr <dmk@mr-paradox.net> wrote:

> Incidentally the code is written to work like this :
>
> while (read X lines in file){
> Process those lines.
> write lines to DB.
> }

Unless you're selecting from multiple database tables in one query,
effective_cache_size shouldn't make any difference.  There's
probably some other reason for the difference.

A couple wild shots in the dark:

Any chance the source files were cached the second time, but not the
first?

Do you have a large checkpoint_segments setting, and did the second
run without a new initdb?

-Kevin

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