1. Ullman book, vol. I, ch. 3.
2. AHV book - part D.
3. Stefano Ceri, Georg Gottlob, Letizia Tanca: What you Always Wanted to Know About Datalog (And Never Dared to Ask). TKDE 1(1): 146-166 (1989).
1. AHV book - chapters 4, 5, 12; a bit of 6.
2. Ullman book, vol. II - chapters ??.
1. Laks V.S. Lakshmanan, Fereidoon Sadri, and Iyer N. Subramanian. Logic and Algebraic Languages for Interoperability in Multi-database Systems. Journal of Logic Programming, 33(2), pp. 101--149, November 1997.
2. Laks V.S. Lakshmanan, Fereidoon Sadri and Subbu N. Subramanian, SchemaSQL -- An Extension to SQL for Multi-database Interoperability . to appear in ACM Transactions on Database Systems (TODS), December 2001.
3. Also see the online library of SchemaLog program examples.
4. Storage structures and indices:
Alanoly Andrews, Laks V.S. Lakshmanan, Shiri Nematollaah, and Iyer N. Subramanian. On Implementing SchemaLog: An Advanced Database Programming Language. Int. Conf. on Information and Knowledge Management, Baltimore, MD, November 1996.
5. SchemaSQL for single DB systems:
Laks V.S. Lakshmanan, Fereidoon Sadri, and Subbu N. Subramanian, On Efficiently Implementing SchemaSQL on a SQL Database System, Int. Conference on Very Large Data Bases (VLDB), Edinburgh, UK, September 1999.
6. Beyond SchemaSQL:
Frederic Gingras and Laks V.S. Lakshmanan, nD-SQL: A Multi-dimensional Language for Interoperability and OLAP, Int. Conference on Very Large Databases (VLDB'98), New York, NY, August 1998.