PostgreSQL 7.1 and ORACLE 8.x

Hello everybody out there,

does anybody of you have experience with PostgreSQL 7.1 and
ORACLE 8.x running simultaneously on the same server (Linux:
Kernel 2.2.16), and could they be connected in any way to share
some data ?

As a beginner in client-server achitectured databases ( I only
have a couple of years experience in programming PARADOX
& ACCES databases), I also have the question, where are the
main differences - except there is an open source software on
the one hand and a commercial on the other - between these two
databases?

What does make ORACLE to be the first choice ?
Under what kind of circumstances could be PostgreSQL the first
choice ?

After all: What are the main missing functions in PostgreSQL to
put it to the same level as ORACLE - or does it still be ?
If not: Will there be a chance in the near future, that I can
supersede an ORACLE- database with a PostgreSQL one, under
any circumstances ?

I really don't want to start a database flame; all I want to get is a
general overview based upon your experience - and yes, I have
read the manuals allready, but maybe not everything in detail :-).

Thank´s for care and for helping me along
Kind regards
Axel

"In a world without walls and fences,
who needs windows and gates?"