Temenos will do the migration. Moving to Oracle DB or any other relational database does not mean that JBASE will be eliminated.
T24 will still write, read, update and delete the jBASE tables, however a driver will translate these operations to Oracle.
For example, a write operation will be performed to the jBASE table, the driver will take over, translate the jBASE record to XML and then write the XML string to an Oracle table.
A read operation will be performed from T24 to jBASE which in turn will go to Oracle, read the record, the result XML will be translated to jBASE format and sent to T24.
Junaid UR Rehman