Mechanisms are provided for integrating a legacy static data storage system with an event based data storage system. Catch-up logic generates, for pre-existing legacy data in the legacy static data storage system, catch-up events for integrating the legacy data in the event based data storage system. A trigger processor generates, at approximately a same time that the catch-up events are generated, triggered events in response to one or more database triggers of the event based data storage system being activated. Both the catch-up events and the one or more triggered events are stored in an event log data structure. An event log monitor processes the catch-up events in the event log data structure to integrate the pre-existing legacy data into the event based data storage system. The event log monitor processes the one or more triggered events after all catch-up events in the event log data structure have been processed.