> I am unable to find any reference to bpchar_ops in the the documentation
> or the General and SQL mailing list archives. Can you tell me where I
> could find out more about what "_ops" are available and what they all
> mean?
The direct answer:
$ pwd
/usr/src/postgresql-6.5/doc/src/sgml
$ find -name "*sgml" -exec grep -il "_ops" {} \;
./ref/create_index.sgml
./arch-dev.sgml -- irrelevant: co-incidental with a processing directive, \label{simple_set_ops})
./bki.sgml
./gist.sgml
./xindex.sgml
My comment:
The deficiency of the docs in regards to operator classes probably
results from the fact that no one is asking about those. The opclass
parameter in CREATE INDEX is no longer required (Herouth has been
around long enough to recall the times when it was).
As you have just witnessed, in a standard situation, you are better
off without knowing about it -- postgres will pick the right opclass
for you. That will not happen, however, when the values you want to
index are of a custom type, or when a built-in type does not have an
opclass of its own (as is the case with the point type). Also, you
need this option to override the default opclass for those types that
can work with multiple opclasses (which is what you attempted to
achieve).
Will anyone with a solid knowledge of the type system want to augment
the existing docs?
--Gene