1-Relational Model 2-Relational Algebra 3-SQL 4-Why Databases 5-Schemas and Views 6-JDBC 7-Normalisation 8-Second Normal Form 9-3NF and BCNF 10-ER model 11-Files 12-Secondary Files 13-Search and B-Trees 15-Concurrency and Transactions 16-Concurrency (Locking)