Illustration repln002.gif shows two master sites named or.world and pa.world maintaining a replication group. There is a two way arrow between the master sites indicating that a database link exists at each site which connects to the other master site.
The materialized view sites sf.world and kc.world each maintain a replication group with the master site or.world. A materialized view site ph.world maintains a replication group with the master site pa.world. A one way arrow points from each materialized view site to its master site, indicated a database link from the materialized view site to the master site.