The problem will not be with the 10gR2 Database. it will be with the 10g client you try to connect with. 1.16 may not be compatible with some 10g Clients. So your best bet would be to use DBD::ORacle1.17. which does work with the 10g clients. If you use an older Oracle client it should still be able to connect to 10gR2 By the way you would be much better off posting your question to dbi-users@perl.org (you don't need to subscribe in order to post, and you won't be automatically subscribed either as very few people use this form for dbi or driver support. dbi-users is where you'll get the best support.