Soundcheck for SQL

The lion's share of datalog features have been incorporated into the SQL3 standard proposal. However, most SQL manuals still recommend to implement user-de ned conditions for data integrity nondeclaratively, by triggers or stored procedures. We describe how to implement known declarative database technology for integrity checking in SQL databases. We show how to represent and evaluate arbitrarily complex constraints in SQL without incurring major disadvantages usually associated to integrity checking in large databases. Error-prone procedural speci cation and laborious maintenance of integrity constraints is avoided by the declarativity of the speci cation language. The costs of evaluation is considerably reduced by an automated translation of declarative speci cations to SQL triggers.