Re: pg_class.reltuples of brin indexes

On Tue, Mar 27, 2018 at 11:28 PM, Alvaro Herrera
<alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> Tom Lane wrote:
>> Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> writes:
>> > I think number of index tuples makes sense, as long as that's what the
>> > costing needs. That is, it's up to the index AM to define it. But it
>> > clearly should not flap like this ...
>>
>> > And it's not just BRIN. This is what I get with a GIN index:
>>
>> Sounds like the same kind of thing we just fixed for SP-GiST :-(
>
> Most likely I modelled the BRIN code after GIN.
>

It's better to create a new index AM that estimates the number of
index tuples, and to update the index stats using that returned value?

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center