Is there a 64-bit build of PostgreSQL for Windows?
There is a 64bit Windows port planned for the 9.0 release. However, the 32bit build of PostgreSQL works on 64bit platforms, and in fact there are good reasons why a 64bit build is less important with PostgreSQL than for some other software: • PostgreSQL relies on the operating system to do much of the caching of data. Since the main limitation of running a 32-bit process is the total amount of memory being addressable, a system that is based on the database engine doing all the caching cannot address all the memory on a system with say 16Gb memory. For PostgreSQL, we leave much of that caching to the operating system which can address it, as long as the OS is 64-bit. • PostgreSQL uses a multi-process architecture, not multi-threaded. In a multi-threaded database server, all client connections share the memory space, and are again limited by the total addressable memory region. With PostgreSQL, you could easily have more than 1Gb per backend (if necessary) without running out of memory,
