"Oneway" Replication from Oracle DB to TimesTen
It is possible (but not simple).
I just made the implementation of ORACLE to TimesTen real time replication.
The solution is based on ORACLE LogMiner utility. Using this tool you can generate the ORACLE transactions in a real time and then ship them to the program (TimesTen side) which will read and apply those transactions to the TimesTen database. The synchronization point is provided between ORACLE and TimesTen by another intermediate ORACLE database. This is very general description, but I can share with you the details if you wish...