Database Adatabase consists of multiple relations Information about an enterprise is broken up into parts with each relation storing one part of the information E.g.: account: stores information about accounts depositor: stores information about which customer owns which account customer: stores information about customers Storing all information as a single relation such as bank(account-number, balance, customer-name,. results in repetition of information(e.g. two customers own an account) the need for null values(e.g. represent a customer without an account) Normalization theory ( Chapter 7)deals with how to design relational schemas Database System Concepts 3.8 OSilberschatz, Korth and SudarshanDatabase System Concepts 3.8 ©Silberschatz, Korth and Sudarshan Database A database consists of multiple relations Information about an enterprise is broken up into parts, with each relation storing one part of the information E.g.: account : stores information about accounts depositor : stores information about which customer owns which account customer : stores information about customers Storing all information as a single relation such as bank(account-number, balance, customer-name, ..) results in repetition of information (e.g. two customers own an account) the need for null values (e.g. represent a customer without an account) Normalization theory (Chapter 7) deals with how to design relational schemas