Re: WIP: BRIN multi-range indexes

Andres Freund <andres@anarazel.de> writes:
> On 2018-02-25 01:30:47 +0100, Tomas Vondra wrote:
>> Note: Currently, this only works with float8-based data types.
>> Supporting additional data types is not a big issue, but will
>> require extending the opclass with "subtract" operator (used to
>> compute distance between values when merging ranges).

> Based on Tom's past stances I'm a bit doubtful he'd be happy with such a
> restriction.  Note that something similar-ish also has come up in
> 0a459cec96.

> I kinda wonder if there's any way to not have two similar but not equal
> types of logic here?

Hm.  I wonder what the patch intends to do with subtraction overflow,
or infinities, or NaNs.  Just as with the RANGE patch, it does not
seem to me that failure is really an acceptable option.  Indexes are
supposed to be able to index whatever the column datatype can store.

            regards, tom lane