Logical <=> Physical questions

I’m considering buying Toad Data Modeler out of my own pocket for a pet project and have some initial questions. I’ve got one chunk of dough to spend on data modeling and that’s all I’ve got, so I have to make the right purchase.

Assuming you’re trying to do the formal thing and start with a logical model, generate the physical model from that, and then generate the code from the physical model: if you make specific hand-done changes to the physical model (which one might do for any number of reasons), does the logical model preserve them the next time you generate the physical model from the logical?

Lastly, my decision has come down to either Toad Data Modeler or XCase. Does anyone here have the knowledge to compare and contrast the two for me?

Thanks in advance.


Hi Steve,

thank you for your feedback. RE logical model and conversion: every time you convert a logical model to physical, new model is created. You can then compare and merge the physical model you generated earlier with the newly generated physical model.

Direct conversion to existing physical model is not possible as well as update of logical model. See my explanation here:


Anoher useful article:

If you do not plan to work with inheritance, use Universal Model instead of Logical. The universal model is based on physical model and e.g. keys migrate to child entities automatically, but inheritance is not supported in Universal model.

Re Xcase or Toad Data Modeler: please try our latest BETA version :slight_smile: