Hi Andreas,
Some comments inline...
Andreas Haufler wrote:
Hi there,
we're trying to use Derby's VTI interface in order to integrate Derby with
Lucene. I already saw some efforts to integrate Lucene via "normal" function
calls, but I think, using the VTI is a better approach. However, I only find
documentation about the "Derby-style table functions" which is a feature of
Derby 10.4 any not yet released. In the code I saw, that the VTI is also
available in 10.3 based on PreparedStatements and some interfaces.
My questions are now,
1) will these "Derby-style table functions" replace the other approach, or
is this just a feature to easily integrate other datasources with return
ResultSet.
Table functions are the right feature for you to use. Technically, VTIs
are an internal Derby feature used mostly for diagnostic purposes.
2) how do I use VTI in 10.3, I know that I have to use something SELECT ...
FROM TABLE(??) <- but I didn't find out what goes in there.
It's not documented, as you've discovered. Your VTI would have to live
in the Derby diagnostics package. To avoid jar-sealing problems, you
would have to crack open the Derby jarball, insert your VTI class into
the diagnostics package, and re-build the Derby jarball. I think you
will end up chasing a lot of frustrating problems if you do this and I
recommend that you avoid this approach.
3) If "Derby-style table functions" are the way to go, when approximately
will a release containing it be available? Mid 2008? End of 2008?
10.4 is currently targetted for late March:
http://wiki.apache.org/db-derby/DerbyTenFourRelease
Hope this helps,
-Rick
thanx+best regards
Andreas Haufler
