I don't really plan on using active record or any of the built in database constructs native to CodeIgniter for database access. I have Oracle, SQL Server, and others. I want to use PHP PDO (unless anyone thinks that's bad) because of the universal aspect of it.
I mainly want CI because of some of the built in libraries and MVC. I also like that it is small and easy to work with.
2.x if it matters.
I did see other questions but none exactly about databases.
Thanks.
edit: It's not that I don't think CI and PHP can take it with large websites. This is solely about using multiple databases of varying companies. I have mostly seen MySQL used with it. I know I can use other databases but again, I don't know if it is more trouble than worth or what.