how to use two webDB together

[AJ Chen <ca...@gmail.com>]

I have two webdb from two separate crawling, but I need to search them
together. What are the options for using two separate webdb together? I see
three approaches, but not sure which is more convenient. Please advise.
(1) First, combine the two webdb and their segments. Is this possible and
how?
(2) If webdb can't be merged, it may be possible to combine index and the
related segments. How?
(3) Keep the two webdb separate, but search the two index at the same time
and combine results at search time. This will probably require adding new
code to search the second index and merge the result hits. What classes
should be modified?

AJ