Relational calculus. Query processing and optimization. Transaction processing: failure, recovery, and concurrency. Database security. Logic-based systems. Parallel ...

Relational databases and SQL were invented in the 1970s, but still dominate the data world today. Why? Relational calculus, consistent data, logical data representation are all reasons that a ...

A database that maintains a set of separate, related files (tables), but combines data elements from the files for queries and reports when required. The concept was developed in 1970 by Edgar Codd, ...