Jan Wieck <JanWieck@Yahoo.com> writes:
> What about a little hint to the buffer management that if it has to
> evict another buffer to physically read this one (meaning the buffer
> pool was full already) then it will not put this buffer at the top of
> the LRU chain but rather at it's end? This way a vacuum on a large table
> will not cause a complete cache eviction.
I think what we really need is a way to schedule VACUUM's I/O at a lower
priority than normal I/Os. Wouldn't be very portable :-( ... but if the
OS offers a facility for requesting this, it'd be worth experimenting
with.
regards, tom lane