Thanks for the information but was not actually asking for it for this question. Simply stating you need to be careful in posting future questions because your database can be one of many versions now.
I also understand your dilemma. You should always know what you have installed. However, even I when testing, get confused as to which version I have just swapped to. You can get your database name and version by running a macro. It is posted here → How do I display the HSQLDB Embedded version?.
By upgrade I mean a newer version of the same database. This is your option but does allow access to newer functionality implemented in a database. With HSQLDB embedded (v1.8.x) it is stuck there for many years and compared to new versions is far behind what can now more easily be done.