Execution

Just for feedback
If you export to the same table that you import from, at what times is it ok to import from, and at what times is it ok to export from? At what times are the other process(s) you are communicating with ok to import and export from the same table? Why introduce the headache and restrictions of all that co-ordination?

Essentially you are using a single shared buffer for communication between maestro and the source process, and the same buffer for communication between maestro and any downstream processes. It would be best to have a separate queue for each thing that maestro communicates with.

Unless I misunderstand something?