Re: Tuning Postgres for single user manipulating large amounts of data

On 12/09/2010 12:36 PM, Paul Taylor wrote:
> On 09/12/2010 15:12, Reid Thompson wrote:
>> On 12/09/2010 09:59 AM, Andy Colson wrote:
>>> On 12/9/2010 8:50 AM, Andy Colson wrote:
>>>> On 12/9/2010 6:25 AM, Paul Taylor wrote:
>>>> You need to bump up your SHMMAX is your OS.
>>> sorry: SHMMAX _in_ your OS.
>>>
>>> its an OS setting not a PG one.
>>>
>>> -Andy
>>>
>>>
>> scroll down to the section on OSX
>> http://developer.postgresql.org/pgdocs/postgres/kernel-resources.html
>>
> Thanks guys, but one think I dont get is why does setting shared_buffers to 40mb break the kernel limit, I mean 40 mb doesnt sound
> like very much at all
>
> Paul

It's not -- from the same page (near the top)
17.4.1. Shared Memory and Semaphores

Shared memory and semaphores are collectively referred to as "System V IPC" (together with message queues, which are not relevant
for PostgreSQL). Almost all modern operating systems provide these features, but many of them don't have them turned on or
sufficiently sized by default, especially as available RAM and the demands of database applications grow.

and/but most of these system defaults originated when system RAM availability was much smaller