I have 2 databases and I want to draw a diagram that show these in Master/Slave Mode. Is there any solution?
1 I would consider custom data flow http://www.uml-diagrams.org/information-flow-diagrams/scheduled-workflow-example.html?context=ifl-examples diagram
2 or partitioned activity diagram (like http://www.uml-diagrams.org/electronic-prescriptions-activity-diagram-example.html?context=activity-examples) where the partitions would represent source database tables (master), target database tables (slave) and the replicator (the pump executing the transformation script)
3 also similar mapping problem is often solved/documented by the Object Relationship Mappers who translate databases from e.g. Java in-memory classes to Oracle SQL persistent tables (back and forth). So look for examples of how they usually document their work plan