Re: Postgresql and multithreading

On 18 Oct 2002 at 13:11, Steve Wolfe wrote:

> 
>   On the recurring debate of threading vs. forking, I was giving it a fwe
> thoughts a few days ago, particularly with concern to Linux's memory model.
> 
>   On IA32 platforms with over 4 gigs of memory, any one process can only
> "see" up to 3 or 4 gigs of that.  Having each postmaster fork off as a new
> process obviously would allow a person to utilize very copious quantities of
> memory, assuming that (a) they were dealing with concurrent PG sessions, and
> (b) PG had reason to use the memory.

Well IIRC PG can not use more than 2Gigs of memory or 250K shared buffers 
(Unless you alter the buffer size itself). This does not become an issue in 
itself.

>   I'm not entirely clear on threading in Linux - would it provide the same
> benefits, or would it suddenly lock you into a 3-gig memory space?

Well, if you need to allocate 3Gig of memory to single process like postgresql, 
it's time to get a 64bit CPU. IIRC linux run on quite a few of them.

HTH
ByeShridhar

--
QOTD:    "Oh, no, no...  I'm not beautiful.  Just very, very pretty."