Slaves can be used for:Horizontal read scalability -- take the load off a master database by spreading reads to a replicated slave.Disaster recovery -- some disasters, such as a hardware failure, can be solved by having a slave ready to propagate to a master. This technique also works to make offline changes to a master/slave pair without having database downtime (see below).Consistent Backups -- without disrupting production usage, a slave can be used to ta