When I tried to use different source-db resource source in CDS blueprints processor an exception from gerrit.onap Code Review - ccsdk/cds.git/blob - ms/blueprintsprocessor/functions/resource-resolution/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/resource/resolution/processor/DatabaseResourceAssignmentProcessor.kt

So looks like it's hardcoded that only processor-db source type can be used. That should be possible to add any source-db type (as like for source-rest)