Martijn van Oosterhout <kleptog@svana.org> writes:
> Can you think of any places at all where 64-bit would make a difference
> to processing? 64-bit gives you more memory, and on some x86 chips, more
> registers, but that's it.
It would be interesting to look into making int8 and float8 be
pass-by-value datatypes to save palloc overhead on machines where
Datum is going to be 8 bytes wide anyway. Of course this would
only help queries that use those datatypes extensively, and it
might be an insignificant savings anyhow :-(
For the most part though I think that the main advantage of 64-bit
for a database is the ability to address more memory. We've been
working slowly towards allowing PG to make better use of large
numbers of shared buffers, for instance.
regards, tom lane