A few things are not clear to me from reading through docs and examples:

    df.wait_for_schedule()

How does this call work? Is it idempotent if I call it from an application? If I run it 2x with the same parameters, does it double tick? Am I invoking this manually from a query console to only do this one time? Am I running this as part of a migration script?

For this[0]:

    -- Wait for human signal (5 minute timeout)
    ~> (df.wait_for_signal('approval', 300) |=> 'sig')

    ~> df.if(
        $$SELECT NOT ($sig::jsonb->>'timed_out')::boolean
            AND ($sig::jsonb->'data'->>'approved')::boolean$$,

Is the `timed_out` a fixed constant that is returned on timeout?

Also not immediately clear: how to handle errors/exceptions?

[0] https://github.com/microsoft/pg_durable/blob/main/examples/i...