SYS 2202 Lecture Notes - Lecture 6: If And Only If, Third Normal Form, Candidate Key
19 Apr 2016
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System architecture: data is stored in servers or in the air, not a proper way to digest it, so we have middle applications to connect you to other people"s virtual data. Files would be the sql component and facebook, for example, is a php component: normalization, why is it important? i) ii) iii) iv) To free the collection of relations from undesirable insertion, update and deletion dependencies. To reduce the need for restructuring the collection of relations, as new types of data are introduced, and thus increase the life span of application programs (1) To make the relational model more informative to users. To make the collection of relations neutral to the query statistics, where these statistics are liable to change as time goes by. E. g: instead of having a single table that stores multiple emergency contacts of a single person in their profile, that component would be separated and stored in a different table to comply with 1nf.
