Another explosive topic is what programming language to use for writing the ETL processes. The choices are somewhat limited as Oracle only offers PL/SQL, Java, and 3-GL pre-compilers for Ada, C, COBOL, FORTRAN, and Pascal. Oracle also offers loading utilities such as SQL Loader, which has a control language. Additionally, people use scripting languages such as Perl and Python to access Oracle databases. And of course, there are numerous third-party vendor tools as well. All have something to offer.
The key point is to select whatever language most of your developers are comfortable with. The runtime differences for loading data via PL/SQL versus Pro-C versus SQL Loader are much more a factor of your developers' comfort level and programming techniques than the speed of the underlying language. For example, an infinite loop in C does not finish any quicker than one written in PL/SQL.