Re: Metadata

Hi
> I am a swiss student in the University of Applied Sciences of Geneva. For
> a report on the different implantation of metadata in PostgreSQL 7.3,
> Oracle and SQL3, I would like you to know if it is possible to answer me
> some questions :

Unfortunatly, this list doesnt respond well to homework questions.  I guess
we kinda think of it as cheating.  I think that school should emulate real
life whenever possible however, therefore you should always use the
resources you would in the business world.

>
> 1) is the system catalog the only one way to have metadata?

You can create a datastructure that holds data about your data, this would
be something you develop into your database and applications.  If you mean
where do you hold information about table structures, column types and
fundimental database organization, then yes, the system catalog is used for
that.

> 2) what are the main differences between PostgreSQL 7.3 and Oracle 9i and

I have worked very little w/ Oracle 8i and nothing w/ 9i so I would not be
qualified to answer this.  I will say that the procedural languages are very
similar.

> between PostgreSQL 7.3 and SQL3?

PostgreSQL is a database platform where SQL3 is a database language.
PostgreSQL complies, fanaticly (but in a good way :-), with the SQL92 and
SQL99 standards.  The specific differences between SQL3 and SQL92 or SQL99
are subjects for a masters thesis and not something I really want to tackle.

Hope that helps a little.

Thanks
Chad