Deviations for protocol version 11
Request flushing can be deferred for ptype_batch_send or higher.For ptype_lazy_send, the response to op_free_statement is deferred;it requires another operation on the connection before the response is sent.
For DSQL_drop and DSQL_unprepare, we recommend flushing immediately so the server at least processes the request, which will prevent longer than necessary retention of metadata locks.