Thanks again for giving wonderful pointers. So if we have collections that have extended references and we have parent collections that are being referenced they would be populated from oracle as the data migration is going on. Like you mentioned we joined the data and then move it together with master tables in mongo db. Do you recommend any etl tools that are good at moving data from rdbms(oracle) into mongo db.
I am guessing there will be one time data load and then there could be scenarios where cdc is only moving changes across. These are two separate scenarios