BIP 10g scheduler schema database capacity requirements?

Hi!

We have Primavera P6 EPPM which came with a 10g BI Publisher, but we have not setup the BI Publisher yet.  Before we can install the Scheduler Schema for the BI Publisher, the DBA wants us to quantify the overhead required on the database in terms of space and amount of redo that could be generated.  

The install guide suggests a 20G tablespace quota for the BIP scheduler user, and while that doesn't sound like much it is a lot compared to the size of our Primavera database.  I think we're just running on a virtual or shared server and trying to minimize the resources.