Log-based site implementation (or site replication) is based on a monitor that watches a log of transactions and propagates these changes to other sites. Generated by the database, this log comprises a stream of database transactions. This is a very efficient way of replicating data from server to server. It also allows you to maintain a remote backup of a primary database. The OpenEdge RDBMS supports site replication using after-imaging (AI) files. For more information on log-based site replication see Implementing log-based site replication.