Re: constraints and sql92 information_schema compliance

Josh Berkus <josh(at)agliodbs(dot)com> writes:
>> No way. The entire point of information_schema is that it is standard;
>> adding non-spec things to it renders it no better than direct access
>> to the PG catalogs.

> Hmmm ... so, per you, we can't add extra views covering non-spec objects to
> the information_schema (like aggregates) because we can't modify it in any
> way. But per Peter we can't add new views to the pg_catalog because we
> want people to use information_schema. I sense a catch-22 here.

I doubt Peter really meant that we can't add any new views; in
particular, for information that is not available from the standard
information_schema it's certainly silly to claim that people should go
to information_schema for it. I do see his point that we shouldn't
unnecessarily duplicate functionality that's available in a standardized
view.

I do have doubts about adding any large number of add-on views to
pg_catalog, because of the privileged place of that schema in search
paths. It'd be better to put them in a separate schema ("pg_info"
maybe?) where they'd pose less risk of conflicts with user-defined names.
Does newsysviews already do this?

regards, tom lane