subject: Major Types of Oracle Replication [print this page] Major Types of Oracle Replication Major Types of Oracle Replication
If one wants to realize full potential of advanced oracle replication facilities, and avoid pitfalls at the same time, he must comprehend the basic architecture they are based upon.
Basically, oracle replication is of four types, including read only materialized views, updateable materialized view, multi master replication and procedural replication. In read only materialized view, the master table' is copied to database, and any changes made in master-table are automatically reflected in snapshot tables' whenever snapshot refreshes. Updatable materialized view is just like read only snapshot, excluding that snapshot site is able to alter data, and send modifications back to master. The snapshot-site decides the frequency of refreshes and frequency at which updates are sent to master.
As far as multi master oracle replication is concerned, the tables are copied to multiple databases, and every database can delete, update or insert records in it. Alterations are often pushed to other databases at the interval that database administrator sets for every replication group. The last is procedural oracle replication that involves copying the call to procedure (or function) to multiple databases. Oracle Replication Service maximises return on investment as processing loads can be offset to the standby database.
The replication of data is quite different from data distribution. When data is dispersed, it can be easily accessed from several locations, but the given table' exists at just one location, and it is this location which is accountable for integrity and security. On the other hand, replicated data resides at several locations, and introduces certain issues like latency and data synchronization that lead to increased complexity level.
