Re: Experimental patch for inter-page delay in VACUUM

Joe Conway <mail@joeconway.com>

From: Joe Conway <mail@joeconway.com>
To: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andrew Sullivan <andrew@libertyrms.info>, pgsql-hackers@postgresql.org
Date: 2003-11-10T05:00:06Z
Lists: pgsql-hackers
Bruce Momjian wrote:
> Agreed, we can't resize shared memory, but I don't think most OS's swap
> out shared memory, and even if they do, they usually have a kernel
> configuration parameter to lock it into kernel memory.  All the old
> unixes locked the shared memory into kernel address space and in fact
> this is why many of them required a kernel recompile to increase shared
> memory.  I hope the ones that have pagable shared memory have a way to
> prevent it --- at least FreeBSD does, not sure about Linux.

I'm pretty sure at least Linux, Solaris, and HPUX all work this way -- 
otherwise Oracle would have the same problem with their SGA, which is 
kept in shared memory.

Joe