Hmm. Think about this. If your perl scripts that access your database are in a non-secure file(system), then any DB userids and passwords in them are vulnerable.

Is it your intent that a human being (you or a trustee) will always be there to enter the password every time your script runs?

Equally, unless the data directories used by your DB are secure, then everything you write into your DB can be read by simply grepping those directories.