22-RelationalDataModel

22-RelationalDataModel - Discussion#22 Relational Data...

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Discussion #22 Chapter 12, Sections 1-2 1/10 Discussion #22 Relational Data Model
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Discussion #22 Chapter 12, Sections 1-2 2/10 Topics Databases Relational database Relations and schemas Keys Tuples and predicates
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Chapter 12, Sections 1-2 3/10 Database A persistent collection of information about various kinds of objects (persons, places, things, events). Each object or entity can be characterized by a set of attributes or properties from a domain. e.g. person(SSN, Name, Address, Phone) Each individual object has a value associated with it for each attribute; this is a tuple and forms a record. e.g. SSN: 123-45-6789 Name: Pat Carter Address: 12 Main Phone: 555-5555 . A set of records is a file (relation, for a relational database). A collection of files is a database (relations or tables, for a relational database). Typical operations on a database: insert – data retrieval delete – summarize data (e.g. averages, totals, mins, …) update – create/delete files A database system helps people manage databases. data storage
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This note was uploaded on 03/02/2012 for the course C S 236 taught by Professor Michaelgoodrich during the Winter '12 term at BYU.

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22-RelationalDataModel - Discussion#22 Relational Data...

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