Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> Tom Lane wrote:
>> Well, considering how seldom new pages will be added to the visibility
>> map, it seems to me we could afford to send out a relcache inval event
>> when that happens. Then rd_vm_nblocks_cache could be treated as
>> trustworthy.
> A relcache invalidation sounds awfully heavy-weight.
It really isn't.
regards, tom lane