BMGT 402 Lecture Notes - Lecture 1: Database, Software System
30 Aug 2018
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Document Summary
Database systems are used in simple and complex situations. Data needs to be described and can be used for certain purposes. If you have data you can find the exact answer to a query. Ex: library database with book information and location, renting movies from redbox, buying things with your credit card, buying clothes from a store. Collection of application programs that perform services for end users. Each program defines and manages its own data. File cannot be automatically updated when one other file gets updated. There is no communication with the information in these files. Limitations/key problems with file based data: separation and isolation of data -each program has its own data set, and the disconnection between programs = unawareness of potentially useful data, duplication of data -same data in different programs causes wasted space. Data dependence: file structure is defined in the program code. Incompatible file formats: different languages used cannot easily access other files.
