Jim Nasby <Jim.Nasby@bluetreble.com> writes:
>> Ahh, I hadn't considered that. So one idea would be to only track
>> negative entries on caches where we know they're actually useful. That
>> might make the performance hit of some of the other ideas more
>> tolerable. Presumably you're much less likely to pollute the namespace
>> cache than some of the others.
> Ok, after reading the code I see I only partly understood what you were
> saying. In any case, it might still be useful to do some testing with
> CATCACHE_STATS defined to see if there's caches that don't accumulate a
> lot of negative entries.
There definitely are, according to my testing, but by the same token
it's not clear that a shutoff check would save anything.
regards, tom lane