Oracle vs PostgreSQL in real life

Okay...

I'm very sceptic today.

I'm making a survey on Oracle 8.0 on NT4 remplacement with a RedHat 7.2/PG 7.2

The customer gave me stuff to migrate, like scripts in Pro*C Oracle that I
migrated successfully with ECPG. Other stuff with Connect by statments, thanks
to OpenACS guys, I migrated this Connect by statments too.

But finaly, with all my mind I explained all queries, made all good, I hope
everything has be done.

The "test" is a big batch that computes stuffs in the database. Here are the
timings of both Oracle and PG (7.2) :

Oracle on NT 4 : 45 minuts to go , 1200 tps (yes one thousand and two hundred
tps)

Linux Red Hat 7.2 with PostgreSQL 7.2 : hours to go (statistically, 45 hours),
80 tps (eighty tps).

Tests were made on the same machine, a pentium 3 600 MHz with 256 Megs RAM and
RAID 5.

We formatted the server and insstalled linux stuff after..

So what you think of SUCH difference between Oracle/NT and Linux/PG ?

I feel very bad in front of the customer, to tell there is a 1:15 ratio between
Oracle / Nt and Linux / PostgreSQL, since I'm real PG fan and DBA in french Open
Souce company...

Thanks a lot for support.

:-(((

--
Jean-Paul ARGUDO