TEST 1 Notes

TEST 1 Notes - TEST TUESDAY Translating Business Rules into...

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TEST TUESDAY Translating Business Rules into Data Model Components Generally, nouns translate into entities Verbs translate into relationships among entities Relationships are bidirectional (variance in how they work) Two questions to identify the relationship type: o How many instances of B are related to one instance of A? (undergrads have one advisor 1to1 and graduates 1 to many) o How many instances of A are related to one instance of B The Evolution of Data Models The Hierarchical Model The hierarchical model was developed in the 1960s to manage large amounts of data for manufacturing projects Basic logical structure is represented by an upside-down “tree” Hierarchical structure contains levels or segments o Segment analogous to a record type o Set of one-to-many relationships between segments o Limited by set end of branch The Network Model o The network model was created to represent complex data relationships more effectively than the hierarchical model o Improves database performance o Imposes a database standard o Resembles hierarchical model o However, record may have more than one parent – relate everything to each other
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This note was uploaded on 11/30/2011 for the course MGT 456 taught by Professor Klein during the Spring '11 term at Clemson.

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TEST 1 Notes - TEST TUESDAY Translating Business Rules into...

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