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Date: Sat, 21 Mar 2015 23:24:16 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: Dmitry Morozovsky <marck@rinet.ru>
Subject: Re: svn commit: r280323 - head/sys/kern
Message-ID: <20150321212416.GU2379@kib.kiev.ua>
References: <201503211501.t2LF1Kj8052521@svn.freebsd.org>
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On Sun, Mar 22, 2015 at 12:16:22AM +0300, Dmitry Morozovsky wrote:
> On Sat, 21 Mar 2015, Konstantin Belousov wrote:
> 
> > > >   Somewhat modernize the SysV shm code:
> > > 
> > > Interesting.
> > > 
> > > Is my understanding correct that postgres still uses shm?  If so,
> > > has someone benchmarked the speedup?
> > 
> > Yes, some versions of Postgres still use SysV shm.  
> 
> To be clarified: IIUC, *all* contemporary versions of PostgreSQL do
> use SHM for shatrd buffers (as PgSQL use process-per-connection model)
>
No.  Recent versions use mmaped shared region for buffers.