How would one go about sizing a data for Red Hat Process Automation Manager (jBPM)? All to documents I have read state you can hook it up to a database (mySQL mostly) but don't give any inclination to default sizing anywhere.
The size of the database will be dependent on the your business requirement or the usages. It will vary as per your implementation.
If the database tables are growing infinitely then you can remove the historical data/clean history tables. Red Hat Process Automation Manager (RHPAM) provide feature to schedule a job and clear the historical data periodically.