Horton

Re: Perfomance degradation 9.3 (vs 9.2) for FreeBSD

Andres Freund <andres@2ndquadrant.com>

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From: Andres Freund <andres@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Palle Girgensohn <girgen@FreeBSD.org>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Francois Tigeot <ftigeot@wolfpond.org>
Date: 2014-04-21T14:51:00Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add shared_memory_type GUC.

On 2014-04-21 10:45:24 -0400, Tom Lane wrote:
> Andres Freund <andres@2ndquadrant.com> writes:
> > If there are indeed such large regressions on FreeBSD we need to treat
> > them as postgres regressions. It's nicer not to add config options for
> > things that don't need it, but apparently that's not the case here.
> 
> > Imo this means we need to add GUC to control wether anon mmap() or sysv
> > shmem is to be used. In 9.3.
> 
> I will resist this mightily.  One of the main reasons to switch to mmap
> was so we would no longer have to explain about SysV shm configuration.

It's still explained in the docs and one of the dynshm implementations
is based on sysv shmem. So I don't see this as a convincing reason.

Regressing installed OSs by 15-20% just to save a couple of lines of
docs and code seems rather unconvincing to me.

Greetings,

Andres Freund

-- 
 Andres Freund	                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services