Philip Warner <pjw@rhyme.com.au> writes:
> Obviously this is not a 7.3 item, but would people support such
> functionality going into a future version?
Actually, I wouldn't. I can think of very few situations where
such caching is useful, and I don't believe that the mechanism required
would pay for itself. In the cases where a cache does make sense,
it's sufficiently application-specific that a generic "cache on a key
consisting of the function arguments" isn't the right thing anyway;
you'll find you want some internal logic to decide what to cache and
what key to use to retrieve it. Furthermore, a generic cache will have
no clue whatever about cache-invalidating events, thus further
restricting its usefulness. (Your suggestion of "flush at transaction
end" is too short-term for most applications, too long-term for some,
and just right for hardly any.)
Build the cache internally to your function if you need it.
regards, tom lane
