IST 359 Study Guide - Quiz Guide: Surrogate Key, Unique Key, Foreign Key

• School: Syracuse University
• Department: Information Studies
• Course: IST 359
• Professor: nosky

Document Summary

Data independence: means of describing data with its natural structure only. Data consistency: minimal redundancy, adopts the dry principle. Ease of use: don"t have to understand implementation to use it. Structural component, manipulative component, set of integrity rules. Composite key: primary key consist more than 1 column. Secondary key: attribute or combination of attributes used for row retrieval from a table. Foreign key: foreign key is attribute in one table whose values either match those of primary key in another table. Entity integrity: impose constraint that each row in relation must be uniquely identiied. Referential integrity: foreign key must contain either null or a value matching a primary key in another table. Planning, analysis, design, implementation, maintenance & support, > conceptual model, logical model/physical model, internal/external model. Default value: a value entered into an attribute for a row when one isn"t speciied. Check constraint: expression which must be evaluated prior to insertion of a row.