Re: FW: Changing the default configuration (was Re: - Mailing list pgsql-hackers

Hi everyone,

Just looked on the IBM website for info relating to shared memory and 
IPC limits in AIX, and found a few useful-looking documents:

The Interprocess Communication (IPC) Overview

http://www-1.ibm.com/support/docview.wss?rs=0&context=SWG10&q=shmget&uid=aix15f11dd1d98f3551f85256816006a001d&loc=en_US&cs=utf-8&cc=us&lang=en#1.1
"This document defines the interprocess communication (IPC) and is 
applicable to AIX versions 3.2.x and 4.x."

Lots of the stuff here is very intro-level, but some still looks useful.


vmtune Parameters

http://www-1.ibm.com/support/docview.wss?rs=0&context=SWG10&q=shmget&uid=aix16934e2f123d4ab3785256816006a0252&loc=en_US&cs=utf-8&cc=us&lang=en
"This document discusses the vmtune  command used to modify the Virtual 
Memory Manager (VMM) parameters that control the behavior of the memory 
management subsystem. This information applies to AIX Versions 4.x."


And an obscure reference to the AIX shmget(2) manpage says that there is 
a non-tunable maximum shared-memory segment size of 256MB:

http://www.unidata.ucar.edu/packages/mcidas/780/mcx/workstation.html#aix

Hope some of this is useful.

Regards and best wishes,

Justin Clift

-- 
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