Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > I have added this item to TODO:
> > 	* Consider use of open/fctl(O_DIRECT) to minimize OS caching
> 
> Why exactly would we wish to minimize OS caching?
> 
> In my mind, Postgres has always relied heavily on the existence of a
> layer of kernel caching.  Disabling that will hurt far more than help.

Not sure. Someone on IRC brought it up.  If we are sequential scanning a
large table, caching may be bad because we are pushing out stuff already
in the cache that may be useful.  It is related to this TODO item:

	* Add free-behind capability for large sequential scans (Bruce)

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman(at)candle(dot)pha(dot)pa(dot)us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

In response to

• Re: O_DIRECT use at 2002-01-04 21:29:51 from Tom Lane

Responses

• Re: O_DIRECT use at 2002-01-04 21:47:10 from Tom Lane
• Re: O_DIRECT use at 2002-01-04 21:53:34 from Brent Verner

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