Re: several questions about R-tree index

"TJ O'Donnell" <tjo(at)acm(dot)org> writes:
> Shouldn't the ~ (contains) operator be included also?
> Isn't ~ the commutator of @ ?

Yeah, it looks like the documentation is in error:

regression=# select amopopr::regoperator,amopstrategy from pg_amop where amopclaid in
regression-# (select oid from pg_opclass where opcamid = 402);
amopopr | amopstrategy
---------------------+--------------
<<(box,box) | 1
&<(box,box) | 2
&&(box,box) | 3
&>(box,box) | 4
>>(box,box) | 5
~=(box,box) | 6
~(box,box) | 7
@(box,box) | 8
<<(polygon,polygon) | 1
&<(polygon,polygon) | 2
&&(polygon,polygon) | 3
&>(polygon,polygon) | 4
>>(polygon,polygon) | 5
~=(polygon,polygon) | 6
~(polygon,polygon) | 7
@(polygon,polygon) | 8
(16 rows)

Of course, the thing that leaps out here is that there are only two
built-in opclasses for rtree. Not exactly confidence building.

> I am considering using R-tree's for other-than-geometric purposes.

I concur with Andrew's suggestion to consider GIST. GIST has its own
issues, but at least there are people looking at it/using it/working on it.
R-tree doesn't seem to have any user community that really cares.

regards, tom lane