Re: how to save primary key constraints

On Tue, Oct 11, 2011 at 6:37 PM, Chris Travers <chris.travers@gmail.com> wrote:
> On Tue, Oct 11, 2011 at 4:33 PM, Raymond O'Donnell <rod@iol.ie> wrote:
>> On 12/10/2011 00:24, J.V. wrote:
>>> pg_catalog table does not exist.
>>>
>>
>> It's not a table, it's PostgreSQL's version of the information_schema
>> catalog:
>>
>>  http://www.postgresql.org/docs/8.4/static/catalogs.html
>>
> Not quite.  PostgreSQL has an information_schema too.
>
> The pg_catalog is the schema of system catalogs for PostgreSQL.  The
> catalogs are not guaranteed to be stable interfaces the way the
> information_schema is.


This -- always look for your answer first in information_schema.  As a
bonus, it's also portable to many other databases and is much easier
to follow.

Only go to the catalogs if your performance requirements are extreme
and/or you are looking for postgres specific info not found in the
standard schema.

merlin