Re: create opclass documentation outdated

Tom Lane wrote:

> In create_opclass.sgml, not only do we have the list of AMs supporting
> STORAGE, but there is also a paragraph describing which AMs do what
> for input datatypes of FUNCTION members (around line 175).

I placed BRIN together with gist/gin/spgist here, namely that the optype
defaults to the opclass' datatype.

> xindex.sgml has that one list you mentioned, but there's not much
> point in fixing that when BRIN indexes fail to be described either in
> 35.14.2 or 35.14.3, where they certainly should be. And there are
> other places throughout that chapter that say that such-and-such AMs
> support each feature as it's discussed.

In 35.14.2 I added the table of strategies in the "minmax" opclasses;
the list for the "inclusion" opclasses would be much longer. Since GIN
doesn't document anything other than its array support, I'm not really
sure that we want/need to document the "inclusion" opclasses also.

In 35.14.3 I added the table of four basic support procs. I think
that's all that's strictly necessary. For inclusion we have a bunch of
additional support procs.

I also added a paragraph to 35.14.5, indicating that "minmax" is pretty
much the same as btree. "Inclusion" opclasses are supposed to support
cross-datatype operators too (supposedly we could support
above/below/containment etc for points relative to boxes, for example,
if we got around to make a decision regarding floating point comparisons
in geometry operators), but we don't have any, so I hesitate to say
anything about this.

Patch attached.

--
Álvaro Herrera http://www.2ndQuadrant.com/
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