Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Date
Msg-id 200602070413.k174DxY07346@candle.pha.pa.us
Whole thread Raw
In response to Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and  (Rick Gigger <rick@alpinenetworking.com>)
Responses Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
List pgsql-hackers
Rick Gigger wrote:
> I was thinking the exact same thing.  Except  the "and just fsync()  
> dirty pages on commit" part.  Wouldn't that actually make the  
> situation worse?  I thought the whole point of WAL was that it was  
> more efficient to fsync all of the changes in one sequential write in  
> one file rather than fsyncing all of the separate dirty pages.

Uh, supposedly the WAL traffic is not as efficient as fsyncing whole
pages if you are doing lots of full pages.

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


> 
> On Feb 6, 2006, at 7:24 PM, Christopher Kings-Lynne wrote:
> 
> >>     * Allow WAL logging to be turned off for a table, but the table
> >>       might be dropped or truncated during crash recovery [walcontrol]
> >>     
> >>       Allow tables to bypass WAL writes and just fsync() dirty pages on
> >>       commit.  This should be implemented using ALTER TABLE, e.g. ALTER
> >>       TABLE PERSISTENCE [ DROP | TRUNCATE | DEFAULT ].  Tables using
> >>       non-default logging should not use referential integrity with
> >>       default-logging tables.  A table without dirty buffers during a
> >>       crash could perhaps avoid the drop/truncate.
> >
> > This would be such a sweet feature for website session tables...
> >
> > Chris
> >
> >
> > ---------------------------(end of  
> > broadcast)---------------------------
> > TIP 2: Don't 'kill -9' the postmaster
> >
> 
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Have you searched our list archives?
> 
>                http://archives.postgresql.org
> 

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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