Manfred Spraul <manfred@colorfullife.com> writes:
> MAX_ALIGNOF affects the on-disk format, correct?
Right, it could affect placement of fields on-disk. I was thinking we
could change it as an easy test, but maybe not ...
If you set up the shared buffers at an appropriate offset, that should
get most of the possible win from aligning I/O transfers, but not all.
It would also be worth looking at the local buffers (see
src/backend/storage/buffer/localbuf.c). The trouble here is, if malloc
returns something that's only 4-byte aligned, aren't we stuck?
There might also be some joy in making src/backend/storage/file/buffile.c
align its buffers suitably, but again the issue is controlling malloc.
regards, tom lane