EPI - Additional event aggregation



I would like to do additional event aggregation to reduce the amount seperate events in the bsm event browser; only working with duplication on key wont do because we want to keep some information from each event visible. 


For example; Event1 contains an external error-reference, Event2 has same key as Event1 and is duplicated but Event2 has its own error-reference. Now I want to be able to see all error-references in Event2 which is now the "top"-event in the duplication "tree".


I have not done that much investigation yet and would appreciate some input before I do; the initial idea was to check if an event is active (looking at key) and then retrieving information from the active event and append it to the new event before duplication takes place and the event is stored. But I have realised that retrieving information about already stored events is not a very straigthforward thing to do in EPI-scripts(?) and doing processing of the event in the "after storing"-phase is not really possible since you retrieve a read-only event-object.

The second idea is to keep a seperate event-cache in memory and cache information about the aggregated events and append this information to new duplicated events. But this creates alot of overhead and additional factors such as error handling(saving the cache-state when the process stops etc..).


Any input is appreciated, thanks!