Cis 109 Assignment 3

1082 words 5 pages
Logical Design
Gregory M Dowell
CIS 111
Professor Thakkar
25 February 2014

Logical Design The purpose of normalization is to create a stable set of relations is representative of the operations of an enterprise. By doing this we are able to reduce redundancy to save space and avoid inconsistencies in data. It also ensures that the design is free of certain updates, insertions, and deletion anomalies (Ricardo, 2012). With normalization as with most anything else there are advantages and disadvantages. The advantages of normalization are: ACID, which stands for atomicity, consistency, isolation, and durability. Atomicity means the transaction is a single unit. Either the entire set of actions is carried out or is not.
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Taking into account the stages of normalization, the following is a breakdown of your organizations database to reflect the process of normalization from 1NF to 3NF. Item | Colors | Price | Tax | T-shirt | red, blue | 12.00 | 0.60 | Polo | red, yellow | 12.00 | 0.60 | T-shirt | red, blue | 12.00 | 0.60 | Sweatshirt | blue, black | 25.00 | 1.25 |

This table is not in first normal form because there are multiple items in the color field, duplicate records, and no primary key. The next table will show the database converted to first normal form. Here there are no redundant attributes. Item | Color | Price | Tax | T-shirt | red | 12.00 | 0.60 | T-shirt | blue | 12.00 | 0.60 | Polo | red | 12.00 | 0.60 | Polo | yellow | 12.00 | 0.60 | Sweatshirt | blue | 25.00 | 1.25 | Sweatshirt | black | 25.00 | 1.25 |

The previous table does not satisfy second normal form since price and tax depends on item, but not color. The following table will be able to be broken down more since the first normal form has been satisfied. Item | Color | T-shirt | red | T-shirt | blue | Polo | red | Polo | yellow | Sweatshirt | blue | Sweatshirt | black | Item | Price | Tax | T-shirt | 12.00 | 0.60 | T-shirt | 12.00 | 0.60 | Polo | 12.00 | 0.60 | Polo | 12.00 | 0.60 | Sweatshirt | 25.00 | 1.25 | Sweatshirt | 25.00 | 1.25 |

The above tables are in second normal form since all attributes now rely

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