EventMap Data Redundancy Issue

In our system data that we receive from source system is event based and on each event only a limited set of data comes. Our reports on the other hand require latest data in filtered form.

Issue: When we push data on an EventMap, Optimize INSERTS a new row into the table, while we want the latest updated row so that queries executed by our reports and monitors are efficient. We even tried pushing data to an EventMap with same timestamp but it was still INSERTing a new row. So is there anyway we can make Optimize UPDATE an existing row in table rather than INSERTing a new one?

Any help on this would be greatly appreciated.

Adeel Javed