The ACMA maintains a database of radio licences which provides a great deal of useful information as well as being a great dataset for experimentation. The problem is that old data periodically gets removed, so it is hard to maintain a historical perspective. This project allows you to pull down data periodically from the official source and import it into your own storage. You can then query and manipulate the data as you see fit.
This dataset is the intellectual property of the Australian Communications and Media Authority, and you must adhere to the terms of use. It is available free of charge, but there are clear limitations around what you can and can't do with the data.
Secondly, this dataset is rather big. Your database will be somewhere in the order of 16GB without the use of any form of compression.