What is the best way to enforce a 'subset' relationship with integrity constraints

Question

For example, given 3 tables:

• gastropod
• snail
• slug

and assuming we want to enforce that

1. every row in \'gastropod\

Answer 1

Check out this thread: Maintaining subclass integrity in a relational database

The thread provides multiple suggestions for SQL Server implementations, and I would be surprised if the ideas couldn't be applied to Oracle as well.