db size reporting

[jeff sacksteder <jsacksteder@xxxxxxxxx>]

I'm going to be working with some rather large datasets and I want to
evaluate the effects of normalization/denormalization on disk space. Is
there a simple way to find the size on disk of a specific database? To
do so with the operating system is rather crude, since it know nothing
about what proportion of the cluster area is allocated for each
database.