Re: Not using index - Mailing list pgsql-general

From Bas Scheffers
Subject Re: Not using index
Date
Msg-id 2191.217.205.40.94.1076601831.squirrel@io.scheffers.net
Whole thread Raw
In response to Re: Not using index  ("scott.marlowe" <scott.marlowe@ihs.com>)
Responses Re: Not using index
List pgsql-general
Hi Scot,

scott.marlowe said:
> So, to start with, try changing random page cost.  you can change it for
As "unrealistic" as it should be, I need <1 before Postgres takes the
bait. Initialy 0.7, to be exact, but later It also worked at a little
higher setting of 1. I have given PG 96Mb of memory to play with, so
likely all my data will be in cache. So no very fast disk (6MB/sec reads),
but loads of RAM.

Should I try tweaking any of the other parameters?

> performance of seq versus index.  you'll often find that a query that
> screams when the caches are full of your data is quite slow when the cache
> is empty.
True, but as this single query is going to be the work horse of the web
service I am developing, it is likely all data will always be in memory,
even if I'd have to stick several gigs of ram in.

Thanks,
Bas.


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