OMIS2000- Chapter Notes

Tcp handles the movement of data between computers

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Unformatted text preview: OMIS 2000 Final Exam Gahtan 17 Database – a group of related files; describes an entity Entity – person, place, thing, or event about which we store and maintain info Attribute – characteristic/quality that describes an entity. Ex. COURSE – Date, Grade, Student ID Data redundancy – presence of duplicate data in multiple data files so that the same data are stored in more than one place or location. Data redundancy occurs when different groups in an organization independently collect the same piece of data and store it independently of each other. Data inconsistency – the same attribute may have different values ex. one database may use Student ID whereas one may use just ID but they code for the same entity Program data dependence – coupling of data stored in files and the specific programs required to update and maintain those files so that changes in program require changes in the data. Ex. changing the postal code entry from 6 to 7 digits to incorporate the space between the three characters can be extremely expensive. Traditional systems also lack flexibility, data sharing, availability, and have poor security. 6.2 – The Database Approach to Data Management Database – a collection of data organized to serve many applications efficiently by centralizing the data and managing data redundancy. Database Management System (DBMS) – software that permits an org. to centralize data, manage them efficiently, and provide access to the stored data by application programs. The DMBS relieves the programmer from separating logical and physical views of the data Logical view – pres...
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