OLTP and DSS on one server

I want to run a OLTP and a DSS on one server-hardware (1 GB RAM, 40 GB HDD RAID5, 2 Pentium III Processors).
The DSS (data Warehouse) has 2 fact tables with 400000 records each one and the OLTP-System has to serve up to 100 Users. I'm using Oracle Version 8.1.5.

What's better ?

1.) Create two Oracle 8i Instances and run each system on an own instance (each instance has less SGA memory then it would have using only one instance)

or

2.) Create one Oracle 8i Instance and locate the two applications in an own schema. (one user for dss and one user for oltp)

Thanks
Robert Received on Thu Dec 14 2000 - 02:52:25 CST