[Xapian-discuss] How to omindex some sub-directories?

[Charles]

Given a directory tree like ...

/foo
|
+-- A
|
+-- B
|
+-- C

... what is the best way to index A and C into a single Xapian database?

AFAIK the alternatives are:

omindex --db /my_db --no-delete /foo /foo/A
omindex --db /my_db --no-delete /foo /foo/B

or

omindex --db /my_A_db /foo /foo/A
omindex --db /my_B_db /foo /foo/B
xapian-compact /my_A_db /my_B_db /my_db

The first alternative does not delete files deleted from the file system
from the database.  Is there any way around this except by emptying the
database and starting over?

The second alternative increases storage and processing requirements. 
OK if needs must but would prefer to avoid.

Are there any better alternatives?

Best, Charles