Automate a nightly CDB compatibility check

Automating CDB is straightforward, thanks to the command-line nature of the tool. A series of commands can be run one after another to automatically compare the backwards compatibility between the two OS releases.

The steps required are:

1. extract the data about OS release A into a database called REF

2. extract the data about OS release B into a database called DER

3. compare the release B for compatibility with the release A

4. generate a report

5. delete contents of REF

6. move contents of DER into REF

The last two steps shift the derived database into the reference directory. This is in preparation for the next comparison when there is a new release. Doing this reduces the execution time by avoiding the need for the first step. It is quicker to copy an existing database than to create one from scratch. However, first step has to be run to create the first reference database.