Re: Experimental patch for inter-page delay in VACUUM - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Experimental patch for inter-page delay in VACUUM
Date
Msg-id 200311102036.hAAKaaX06203@candle.pha.pa.us
Whole thread Raw
In response to Re: Experimental patch for inter-page delay in VACUUM  (Neil Conway <neilc@samurai.com>)
List pgsql-hackers
Neil Conway wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Another idea --- if fsync() is slow because it can't find the dirty
> > buffers, use write() to write the buffers, copy the buffer to local
> > memory, mark it as clean, then open the file with O_SYNC and write
> > it again.
> 
> Yuck.

This idea if mine will not even work unless others are prevented from
writing that data block while I am fsync'ing from local memory --- what
if someone modified and wrote that block before my block did its fsync
write?  I would overwrite their new data.  It was just a crazy idea.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073
 


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