Databases that learn

"A new generation of security software studies the way people normally access a database to identify hackers."

Now, this sounds cool. Symantec is developing software that could enable databases to differentiate data access patterns that could help to identify hacking attempts and alert administrators.
But I wonder if this is necessary, and how would this impact the performance of the database? One would have thought that by implementing proper software design principles, most problems would be solved without having to resort to this. Nonetheless, this is an interesting proposition.