The *.cfs file is an index file generated by Lucene, an open source search engine.
When the Enterprise Manager receives a Transaction Trace(TT), it stores it in to an object oriented database and ask Lucene to create an index on the TT for search queries. NOTE :This object oriented database is not the SmartStor database.
When the user does a historical query or time range query from workstation, EM searches into Lucene index file, and presents the user with header information.
When the user selects a particular TT, EM gets its information from the traces database.