week11 - Introduction to Database Concepts A Database is a...

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Introduction to Database Concepts A Database is a collection of data for describing the activities of an enterprise. A Database Management System (DBMS) is software that is designed to create, access, maintain a database in an effective (functional) – efficient (cost) manner. 1 st database system is IMS (an IBM system) (hierarchical model) developed in 1960’s. Relational model, 1970, E. F. Codd. Transactional management. File Systems vs. DBMS - File systems coordinate only the physical access. - DBMS DBMS: 1) Provides data independence (physical; changing file structures won’t affect user application)(logical) 2) Reduces data redundancy; we have one central storage 3) Provides security. 4) Provides data integrity (correctness). 6) Reduces application development time. File System DBMS Architecture DBMS Query Results View 1
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View 2 View n External Level Conceptual Level . . . . . . . . . . . . . . . . . . (External Schema) Physical Level Conceptual Schema
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Physical Schema External Schema -> is what a user wants to see Conceptual Schema -> describes data in terms of the data model of DBMS Physical Schema -> specifies storage details
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week11 - Introduction to Database Concepts A Database is a...

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