Re: compiling, performance of PostGreSQL 8.3 on 64-bit processors

> 1. I have heard of problems arising from compiling PostGreSQL (8.3) on
> 64-bit
> processors. What sort of problems am I likely to encounter and how
> should I fix
> them? We are will run Linux Redhat 5 on a Dell PE2950 III Quad Core
> Xeon E54
> 2.33 GHz, and a Dell PE2950 III Quad Core Xeon L5335 2.0 GHz.
>
> 2. Are there performance problems running PostGreSQL 8.3 on a 64-bit
> processor?
>

I have a few more questions on the 64-bit topic. Is there any benefit
to running a 32-bit OS (rhel 5 in this case) on a server with more than
4 GB of memory? In other words, can the OS-level cache take advantage
of more than 4 GB of memory? Can a process (such as PG backend) use
more than 4 GB of shared memory on a 32-bit OS? Or is the 4 GB memory
point the place where you normally transition to a 64-bit OS?

For people with experience running postgresql on systems with 16+ GB
of memory, what parameter settings have you found to be effective?
(This would be a large database that's mostly read-only that we'd
like to fit completely in memory)

Is it possible to backup (pg_dump) from a 32-bit OS to a 64-bit OS,
or is a plain SQL dump necessary?