ch4 - 1. What is a field? Individual piece of data/Made up...

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1. What is a field? –Individual piece of data/Made up of one or more bytes, or characters/Examples: name, address, phone number 2. What is a record? –Fields that are grouped together for a specific purpose 3. What is a primary key? –A field, or group of fields, that uniquely identifies an individual record/Student id number for records describing students a. What is a likely primary key for a citizen of the United States? SSN b. What is a likely primary key for an automobile? VIN c. What is a likely primary key for a student at a university, such as SLU? Banner ID 4. What is a drawback of using a File System? –Inability to share data/Inadequate security/Difficulties in maintenance and expansion/Allows data duplication (e.g. redundancy) 5. What is a deletion anomaly?–Failure to simultaneously delete all copies of redundant data Insertion?–Data needs to be entered more than once when the data is located in multiple file systems Modification?–Redundant data in separate file systems becomes inconsistent
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This note was uploaded on 05/03/2011 for the course SPAN 110 taught by Professor Jones during the Fall '10 term at Saint Louis.

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ch4 - 1. What is a field? Individual piece of data/Made up...

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