Schemas (Re: AW: Unhappy thoughts about pg_dump and objects inherited from template1)

Philip Warner writes:

> I'd be very interested if someone could post the current thinking re:
> schemas, catalogs, and environments, because the way I read the SQL99 docs,
> the catalog seems to correspond to a single postgres installation, and a
> schema seems to correspond to a postgres database (ie. tables and views are
> defined in a schema, and schemas are defined in a catalog, and catalogs are
> defined in an environment, and it looks like the environment is akin to the
> file system/implementation & postmaster).

The thing you get from initdb is a "cluster of catalogs", a database is a
"catalog", a schema is something below a catalog. (There is no such
thing as an "environment" as a hierarchy level.) The idea was most likely
that a schema would be a purely logical hierarchy but a catalog may be a
physical hierarchy. (For example, it is not required that you can access
more than one catalog from a connection.)

I think all people that were interested in this issue agreed with this.
(If not, you better speak up, because I'd like to see schemas implemented
ASAP.)

--
Peter Eisentraut peter_e(at)gmx(dot)net http://yi.org/peter-e/