Large Transactions to use Statement Binlog Format

When replicating large transactions with binlog_format=MIXED, the server will always try to binlog using ROW format because it is safer. However, for large transactions, this can result in significant overheads, e.g. when writing the event data to disk or sending the event data to the slave. This can be optimized with some configurable threshold which would force the slave to log the transaction using STATEMENT binlog format instead.