The initial table synchronization feature has not been supported yet,
but there was the confusing header comment about it in logical/worker.c.
* launcher for every enabled subscription in a database. It uses
* walsender protocol to communicate with publisher.
*
- * The apply worker may spawn additional workers (sync) for initial data
- * synchronization of tables.
- *
* This module includes server facing code and shares libpqwalreceiver
* module with walreceiver for providing the libpq specific functionality.
*