Re: Do BRIN indexes support MIN/MAX?

On Thu, 30 Mar 2023, 05:03 Andrey Klochkov, <diggerk@gmail.com> wrote:

> BRIN indexes seem to work perfectly well for our purposes, and they are so
> tiny compared to B-Tree. Selecting min/max values is very expensive though.
>
> In my case the table is ~2.5TB (530M records), while the whole BRIN index
> is 16MB. I think it'd be totally fine to scan all BRIN pages, it'd be way
> better than doing table scan.
>

brin indexes don't work the way you would hope for.  the stored min/max
values per range guarantees that all values in the underlying relation
pages are contained in that range, but it doesn't mean that those min/max
values are still present in the table, so you can't deduce in which range
the current min or max value is from there.

>