Biggest advantage with OCP (as long as you didn't cheat), is the exposure to all aspects of the product. You may not fully understand a concept, but you are aware of its existence and how it might be used to provide a solution.

I recently ran into a data warehouse system designed by an experience DBA (3 years+) ... the DBA had no idea of bitmap indexes and how they can be used on columns in a where clause with low-cardinality.

There is such a thing as experience and then there is real experience. I have ran into guys with one year who would run circles around guys with 5 years that never did much more then change back up tapes.

Gee,
OCP 8i, 9i DBA
MCSE