Re: Advice on selecting good values for work_mem? - Mailing list pgsql-performance

From Tom Lane
Subject Re: Advice on selecting good values for work_mem?
Date
Msg-id 16388.1165510978@sss.pgh.pa.us
Whole thread Raw
In response to Advice on selecting good values for work_mem?  (Bill Moran <wmoran@collaborativefusion.com>)
Responses Re: Advice on selecting good values for work_mem?
List pgsql-performance
Bill Moran <wmoran@collaborativefusion.com> writes:
> Does the creation of a temp file trigger any logging?

No; but it wouldn't be hard to add some if you wanted.  I'd do it at
deletion, not creation, so you could log the size the file reached.
See FileClose() in src/backend/storage/file/fd.c.

> That leads to my other question.  Assuming I've got lots of
> connections (which I do), how can I determine if work_mem is too
> high?

When you start swapping, you have a problem --- so watch vmstat or
local equivalent.

            regards, tom lane

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