SQLite backend: automatically generate queryset via EGL/EGX
Unfortunately, Greycat does not seem to be maintained by DataThings anymore, so it won't get the benefit of any future updates to its underlying backends, and the issue of being unable to "forget" past history will stay there. Given the good results with the SQLite backend, it may be good to try implementing a time-aware backend using the SQLite backend as a base.
If we're not careful, we may have significant duplication between the timeaware and non-timeaware versions of the backend. It may be best to refactor the backend to use a model-driven approach, where the Java code encapsulating the SQL queries is produced from models. That way, we could use model-to-model transformations to produce the timeaware versions of most queries and the schema from the non-timeaware one, without as much duplication.