From: Alvaro Herrera
> I think seqscanning the hash table is going to be too slow;
Ideriha-san
> idea of having a dlist with the entries in LRU order (where each
entry
> is moved to head of list when it is touched) seemed good: it allows
you
> to evict older ones when the time comes, without having to scan the
rest
> of the entries. Having a dlist means two more pointers on each
cache
> entry AFAIR, so it's not a huge amount of memory.
Absolutely. We should try to avoid unpredictable long response time
caused by an occasional unlucky batch processing. That makes the
troubleshooting when the user asks why they experience unsteady
response time.
Regards
MauMau