Re: Minmax indexes

Fujii Masao wrote:

> I've not read the patch yet. But while testing the feature, I found that
> 
> * Brin index cannot be created on CHAR(n) column.
>    Maybe other data types have the same problem.

Yeah, it's just a matter of adding an opclass for it -- pretty simple
stuff really, because you don't need to write any code, just add a bunch
of catalog entries and an OPCINFO line in mmsortable.c.

Right now there are opclasses for the following types:

int4
numeric
text
date
timestamp with time zone
timestamp
time with time zone
time
"char"

We can eventually extend to cover all types that have btree opclasses,
but we can do that in a separate commit.  I'm also considering removing
the opclass for time with time zone, as it's a pretty useless type.  I
mostly added the ones that are there as a way to test that it behaved
reasonably in the various cases (pass by val vs. not, variable width vs.
fixed, different alignment requirements)

Of course, the real interesting part is adding a completely different
opclass, such as one that stores bounding boxes.

> * FILLFACTOR cannot be set in brin index.

I hadn't added this one because I didn't think there was much point
previously, but I think it might now be useful to allow same-page
updates.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services