Hello,

Xapian have remote database mode:
http://xapian.org/docs/remote.html

Do you plan use it in future? I have more then 8 million letters and my
xapian db use 50 gb store :)

If I can use remote database, I will move database to external server
from my work PC (with Pentium 4) it will be very fast! :)

Thank you!

-- 
Best regards,
Roman Kravets