Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> And I think somebody already thought about it (c.f. ALIGNOF_BUFFER), it
> just wasn't updated in the last 10 years.
No, ALIGNOF_BUFFER is there because we read something that said that I/O
transfers between userspace and kernel disk cache would be faster with
aligned buffers. There's been no particular thought given to alignment
of other data structures, AFAIR.
It may well be that your proposal is spot on. But I'd like to see some
data-structure-by-data-structure measurements, rather than assuming that
alignment must be a good thing.
regards, tom lane