I am looking at a linux machine for a PG install with 32G of RAM. I have never installed on anyting with more than 2 or 3 Gigs before. In order to access that 32 Gigs do I have to use 64 bit OS and PG? Is there any reason not to use a 64 bit? With a 32-bit version of PG can the 32 G of RAM be used for caching?