Обсуждение: Limits to size of shared buffers?

Are there any limits to the size of the shared buffers parameter (as in,
can Postgres go beyond a 2 GB size when I do something like

shared_buffers = 262144   # uses 2 GB

I had set my system shared memory to more than 2 GB, but couldn't get
this line to work (Postgres returned an error when starting up).  I
backed down to

shared_buffers = 196608   # uses 1.5 GB

and everything was happy.

--
Jeff Boes                                      vox 269.226.9550 ext 24
Database Engineer                                     fax 269.349.9076
Nexcerpt, Inc.                                 http://www.nexcerpt.com
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Jeff Boes <jboes@nexcerpt.com> writes:
> Are there any limits to the size of the shared buffers parameter (as in,
> can Postgres go beyond a 2 GB size when I do something like

Probably not; IIRC the size of the shared memory segment is calculated
using signed integers, so it had better stay under 2Gb.

            regards, tom lane

Jeff,

You have to set your system to a little more than 2 GB because there are other
parameters which also require some shared memory. Just experiement with the
values a little and you'll see where the maximum is. If you have more than 2
GB or RAM and your system allows you to go over 2 GB, set it maybe to a max
of 2.5 GB and try to start up postgres again.

Best regards,
Chris

On Monday 19 August 2002 16:32, Jeff Boes wrote:
> Are there any limits to the size of the shared buffers parameter (as in,
> can Postgres go beyond a 2 GB size when I do something like
>
> shared_buffers = 262144   # uses 2 GB
>
> I had set my system shared memory to more than 2 GB, but couldn't get
> this line to work (Postgres returned an error when starting up).  I
> backed down to
>
> shared_buffers = 196608   # uses 1.5 GB
>
> and everything was happy.

--
Chris Ruprecht
Network Grunt and bitpusher extraordinaire