Databases

Reasons for a DBMS (cont'd)

A DBMS provides Data independence.

One must be able to change storage mechanisms and formats without having to modify all application programmes. For example:

• method of representation of alphanumeric data (e.g., changing date format to avoid Y2000 problem)
• method of representation of numeric data (e.g., integer vs. long integer or floating-point)
• units (e.g., metric vs. furlongs)
• record structure (example)
• file structure (sequential, sorted, indexed, etc.)

Slide show generated from dbms.html by Weasel 2007 Mar 21