Oracle provides two basic technologies for general replication between two or more Oracle databases, namely, advanced replication and streams based replication. The streams based replication provides a more efficient solution than the one based on advanced replication. Rather than synchronously capturing changes in the materialized view logs, which adds overhead to the transaction, streams mine the redo logs created by the updates to the database and create change logs to send to the target database system. This architecture also allows the change to be replicated to more than one system much more quickly. The advanced replication also has some restrictions with
SDO_GEOMETRY types that are harder to work around.
In this section, we will describe the streams based replication for the tables with
SDO_GEOMETRY columns. Note that even the native streams based replication has restrictions for the tables with
SDO_GEOMETRY columns. But procedures can be easily implemented...