Re: Is Patch Ok for deferred trigger disk queue? - Mailing list pgsql-hackers

I assume this will not be completed for 7.4.  I will keep the emails for
7.5.

One idea I had was to use the existing sort_mem parameter to control
when to force the deferred trigger queue to disk --- it doesn't have
anything to do with sorting, but it does have the same purpose, to force
thing to disk when we consume enough RAM.

---------------------------------------------------------------------------

Bruce Momjian wrote:
> 
> Stuart, were are on this patch?  Seems we need GUC additions, though I
> can do that for you, and changes to write the head to disk.  Was that
> completed?
> 
> ---------------------------------------------------------------------------
> 
> Stuart wrote:
> > Tom Lane wrote:
> > 
> > > Stephan Szabo <sszabo@megazone23.bigpanda.com> writes:
> > > 
> > >>As a side question, it looks to me that the code stores the first trigger
> > >>records in memory and then after some point starts storing all new records
> > >>on disk.  Is this correct?  I'd wonder if that's really what you want in
> > >>general, since I'd think that the earliest ones are the ones you're least
> > >>likely to need until end of transaction (or set constraints in the fk
> > >>case) whereas the most recent ones are possibly going to be immediate
> > >>triggers which you're going to need as soon as the statement is done.
> > > 
> > > 
> > > Good point.  It would be better to push out stuff from the head of the
> > > queue, hoping that stuff near the end might never need to be written
> > > at all.
> > > 
> > >             regards, tom lane
> > Hmmm.... I see your point. I will change the patch to write the head to
> > disk and reenter when the development branch splits off.
> > Also I've noticed that there is an fd.h which has file routines which I
> > should be using rather than the stdio routines.
> > I will also clean up those errors.
> > Thank you,
> > - Stuart
> > 
> > 
> > 
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> 
> -- 
>   Bruce Momjian                        |  http://candle.pha.pa.us
>   pgman@candle.pha.pa.us               |  (610) 359-1001
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--  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