Anderson Carniel <accarniel(at)gmail(dot)com> writes:
> I would like to know if the PostgreSQL provides a memory function that
> allocates aligned memory.
Not beyond MAXALIGN (although the shared-memory alloc functions do align
to cacheline boundaries IIRC).
> If not, according to your experience, is there a
> significance difference between the performance of the O_DIRECT or not?
AFAIK, nobody's really bothered to measure whether that would be useful
for Postgres. The results would probably be quite platform-specific
anyway.
regards, tom lane