Fastest way to perform subset test operation on a large collection of sets with same domain

Question

Assume we have trillions of sets stored somewhere. The domain for each of these sets is the same. It is also finite and discrete. So each set may be stored as a bit field (eg: 0

Answer 1

If an RDBMS was your only option, I would recommend looking at this interesting article on modelling a DAG in SQL:

http://www.codeproject.com/KB/database/Modeling_DAGs_on_SQL_DBs.aspx?msg=3051183

If you can't afford Oracle or MSSQL, have a look at PostgresQL 9, which supports recursive queries. It's also supported cross joins for quite some time.