The following functionality is currently not supported:

• Table cluster related DDL.
• Switchover/failover/flashback.
• No support for encrypted data (Transparent Data Encryption TDE).
• No support for compressed data. 
• External tables
• Nested tables 

• NOLOGGING hint - This operation does not put the data in the redo log so it is therefore not logged.

• APPEND hint- This operation does not put the data in the redo log so it is therefore not logged.

• Sqlloader with direct option- This operation does not put the data in the redo log so it is therefore not logged.

• LOBs with CTAS (create table as select) 

• Deferrable Constraints *** when target database is not Oracle
• Online Table Move (12.2 feature)
• Proxy Pluggable Database
• Application Containers and Application Container Pluggable Databases

The following script will check to see if the tables are clustered:

Prompt Specify owner for the tables that you want to replicate
Prompt Specify table_name(s) for the tables that you want to replicate. % for all.
select owner, table_name, cluster_name, iot_name, iot_type 
from sys.dba_tables 
where (cluster_name is not null
and owner = upper('&owner')
and table_name like upper('&table_name');

*** Oracle to Non Oracle Db target - "Deferrable Constraint Deferred" is not supported with Default Optimistic Commit Replication. A Pessimistic Commit must be used when Deferrable Constraints exists on source table and oracle is not a target database.