Backend Database for BPM System Development

Dear Sirs,

I am working on development of backend architecture for a customer BPM system and have a few questions. First the background: the main requirements for the databases are to 1) save information on their processes, and 2) to save information used by the BPM system to control the business processes.

They prefer to build the BPM system themselves, rather than buy a system "off the shelf" and be locked into a single vendor. My questions are these:

1. Would the database structure (Oracle, Microsoft SQL Server, IBM DB2 or Sybase) be best served with a database and a data warehouse and how often should the data warehouse be updated? They anticipate about 100 transaction updates per hour for their processes.

2. Should the communication between systems be done with proprietary EAI or based on the BPM XML standards that are currently under development (and will probably change)?

Thank you,
Sanjay