For clarity, the wait_for_start option
replaces the none option in Replication Server
12.6. none is retained for backward compatibility.
wait_for_start specifies that a transaction can start as soon as the transaction scheduled to commit immediately before it has started.
When wait_for_start is used along with the origin partitioning parameter, transactions from each origin are sent to separate DSI executor threads. This method assumes that multiple origins updating the same replicate have built-in contention control, so they can be safely applied in parallel to the replicate.
