Re: No stats after promoting standby?

On Mon, Dec 4, 2017 at 4:36 PM, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
wrote:

> The optimizer stats are not lost on crash or promote actually; these are
> stored in pg_statistic (not in the stats collector) and *are* part of
> regular "data".
>
> ...
>
> I think it's pretty common misunderstanding -- it's not easy to see the
> boundary between pg_statistic and pg_stat_* tables.

Thanks for this. I thought I remembered being corrected on this before
(probably on this very list) and just came to think of it at the end of my
last message.

So what, exactly ARE the pg_stat_* tables? Is that the data stored in the
files in stats_temp_directory? How do they differ from pg_statistic?

I've found this blog post that seems to answer that question with a "Yes":
https://blog.pgaddict.com/posts/the-two-kinds-of-stats-in-postgresql

--
Don Seiler
www.seiler.us