Re: Proposed LogWriter Scheme, WAS: Potential Large - Mailing list pgsql-hackers

From Greg Copeland
Subject Re: Proposed LogWriter Scheme, WAS: Potential Large
Date
Msg-id 1033935666.14317.36.camel@mouse.copelandconsulting.net
Whole thread Raw
In response to Re: Proposed LogWriter Scheme, WAS: Potential Large  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Dirty Buffer Writing [was Proposed LogWriter Scheme]  ("Curtis Faith" <curtis@galtair.com>)
List pgsql-hackers
On Sun, 2002-10-06 at 11:46, Tom Lane wrote:
> I can't personally get excited about something that only helps if your
> server is starved for RAM --- who runs servers that aren't fat on RAM
> anymore?  But give it a shot if you like.  Perhaps your analysis is
> pessimistic.

I do suspect my analysis is somewhat pessimistic too but to what degree,
I have no idea.  You make a good case on your memory argument but please
allow me to further kick it around.  I don't find it far fetched to
imagine situations where people may commit large amounts of memory for
the database yet marginally starve available memory for file system
buffers.  Especially so on heavily I/O bound systems or where sporadicly
other types of non-database file activity may occur.

Now, while I continue to assure myself that it is not far fetched I
honestly have no idea how often this type of situation will typically
occur.  Of course, that opens the door for simply adding more memory
and/or slightly reducing the amount of memory available to the database
(thus making it available elsewhere).  Now, after all that's said and
done, having something like aio in use would seemingly allowing it to be
somewhat more "self-tuning" from a potential performance perspective.

Greg


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