After the ChangeSet 1.1892.20.1 2005/08/24 (Bug #12562) SYSDATE() is not an alias
   of NOW() and is unsafe for replication.
   `SYSDATE()' backward compatible aliasing clashes with the idea #12562 
   fix. To make it safe-replicatable we have to either use RBR or to restore
   the pre-5.0 style.
   --sysdate-is-now command line flag was introduced to provide backward compatibility.