CS458 Lecture Notes - Lecture 6: Multilevel Security, Zip Code, Database Security

• School: University of Waterloo
• Department: Computer Science
• Course: CS458
• Professor: www

Document Summary

Database queries: most popular query language is sql, select address from name-zip. Where (zip = "43210") and (name = "adams": prints address of family in relation name-zip whose zip code is 43210 and whose name is adams, select name, airport. Where name-zip. zip = zip-airport. zip: prints each family name and their airport by joining relations name-zip and zip-airport, select count(name) from name-zip. Where city = "columbus": prints number of families in columbus, can also do other computations, like sum, min, or avg, result of a query is a subschema. Security requirements: physical database integrity, logical database integrity, element integrity, referential integrity, auditability, access control, user authentication, availability. Database integrity: logical and physical integrity, protect against database corruption, allow only authorized individuals to perform updates, recover from physical problems (power failures, disk crashes,, perform periodic backups, keep log of transactions to replay transactions since last backup.