BPM performance rely on your implementation.
DB can become a bottleneck depending your workload and your audit/logging settings.
But as you can scale the number of IS’s in a clustered process runtime, and a MWS cluster, you can also scale databases.
At the end you need to set a proper QA environment, identify bottlenecks and take proper actions/solutions before moving to production.
#webMethods#Integration-Server-and-ESB#Adapters-and-E-Standards