"Ed L." <pgsql(at)bluepolka(dot)net> writes:
>> I wouldn't panic. 99% of the value of a 64-bit box for database work
>> is that you can handle more than 4Gb worth of RAM for disk cache. Since
>> in Postgres's worldview most of the disk caching is supposed to be done
>> by the kernel, it really matters not whether the Postgres executables
>> think they are 32-bit or 64-bit. All you need is a 64-bit kernel.
> The HPUX gurus on http://forums1.itrc.hp.com testify that kernel caches
> above approximately 600MB are counter-productive to performance.
Why? And why would you think that whatever effect is limiting the
performance would not also apply to Postgres?
regards, tom lane