These are multiple questions here.
(1) No, SQL Server is accessed best via the SQL Native Client, ADO/MDAC/OLE-DB. Performance-wise ODBC is not recommended at all, although it still may be the most viable option in certain cases.
(2) Thrift is only an RPC-mechanism, which has nothing to do with DB in General. This is a completely different aspect. However, Thrift can of course be used, and in fact it is actually used by the NoSQL database Apache Cassandra
I'd recommend to first find out what kind of DB is most suitable for your use case: It may be a typical SQL database, or it may be a classical ISAM or even something like Cassandra, CouchDB or MongoDB. Once you know that, you'll surely find out how to conect with the DB of your choice - or just ask another question :-).