Categorising data

In developing a data structure which will provide for the needs of many different research projects, there’s a difficult balance to be struck.
The structure needs to be generic enough to cope with the very different needs of all these projects (some are modelling cities across a couple of days, others modelling the whole world for several decades!) but still offer some kind of separation between the projects’ data so a project can easily select just “its” data and not be bothered with hundreds of events which don’t concern them. I want project working to be straight-forward and, crucially, collaboration to be as easy as changing a WHERE statement.
In the coming weeks I’m going to try and research ways of sensibly dividing up data which is all stored in one big table but which relates to different project areas (but may relate to more than one project area, or just be generic).

Watch this space. Thoughts are welcome.