Oracle Distributed Systems

Advanced Replication Limitations

Finally, note that there are some restrictions on what you can and cannot do in a replicated environment:

• There is no support for cascading deletes. As an alternative, you may consider writing a trigger on the master table to delete child records.

• Sequences do not replicate. If you use sequences to populate key fields, be sure to designate a range of sequence values in each master database that is large enough to avoid key collisions for the life of the application.

• There is no support for local customization of replicated tables. In other words, replicated tables must have an identical shape in each master database.

• The datatypes LONG, LONG RAW, and HHCODE do not replicate. You may replicate tables containing columns of these datatypes, but DML to these columns will not propagate to other master sites. I recommend using the CLOB and LOB datatypes available in Oracle8.