Friday, September 10, 2004 12:15 AM
Thought I would take some time to answer myself.
1) The .del file is for entries that are deleted from the previous indexing that are no longer valid.
2) The .f1, .f2 ... files are internal and not interesting to developers other than those wanting to completely refactor Lucene.
The most interesting file is the .cfs, which is a compound file that includes the entries of each document (Lucene Document) and other fields like the summary and whatever else you have included in your implementation of the "demo" package.