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Unformatted text preview: Chapter 4 Relational Databases Relational Learning Objectives Learning Understand the difference between Understand relational database and file-based systems relational Describe a relational database Understand the difference between logical Understand and physical views of a database and Be able to construct well-structured tables Be to properly store data to Data Hierarchy
Accounts Payable File Example Accounts
Database Database Customer File Record1 Vendor1 Field 1 Vendor Number Field 3 Web Address Field 5 City Field 7 Zip Code Vendor File Record 2 Vendor 2 Inventory File Record N Vendor N Field 2 Vendor Name Field 4 Street Address Field 6 State Field 8 Country Types of Files Types
Two Basic Files Two Master File Stores information about Resources of the organization Agents with whom it interacts Permanent (__________) Exists across fiscal periods Individual records are frequently changed Occasionally records are added/deleted Conceptually similar to the ______ Transaction File Stores information about Specific business transactions (events) That occur during a __________ Not permanent (_______) Usually maintained on-line For one fiscal period Closed to the _________ Conceptually similar to the _____ Database Systems Address the problem of file proliferation Data integration Data sharing Components Database Database management system (DBMS) Application programs File-based Approach File-based
Master File 1 Master Data: ABCD Master File 2 Data: ACD Master File 3 Data: ABDE Purchasing Program Receiving Program A/P Program Database Approach Database
Database Database Data: ABCDE DBMS Purchasing Program Receiving Program A/P Program Logical & Physical Views of Data The ________ view is how the user or programmer The conceptually organizes and understands the data. conceptually The ________ view is how and where the data are The arranged or stored. arranged The benefit of separating the two views is: Logical & Physical Views of Data Logical
Logical view: Logical
STUDENT ID 451087475 123635988 662345582 573447913 259187364 582597320 226371961 NAME (Last, First, MI) HOME ADDRESS STREET 6214 Bonner 4806 East 42nd 2021 Elm 1315 Dover 3165 Glove CITY Houston Spring Katy Alief Houston Houston STATE TX TX TX TX TX TX TX ZIP 77024 77081 77017 77530 77040 77022 77008 HOME PHONE 7137818301 7134652328 7132404588 2815589553 7137434276 7137830183 2815317548 CR HOURS SEM 15 12 15 18 12 15 12 TOT 45 120 95 37 84 118 75 Decker, William B 5193 Elton Elliott, James D Su, Alice S Able, Robert A Nguyen, Kim H Grimes, Gerald Shah, Mohan 9197 Havner Ln Houston Physical view:
11 10 11 00 10 00 01 The Database Management System
(DBMS) (DBMS) Links the ___________ with the __________ of users Allows users to access, update, or query the database Allows without regard to ______________ without Allows users to change their logical view without Allows changing the way the data are ______________ changing The database administrator (DBA) can change the The way the data are physically stored without affecting _________________________ _________________________ The DBMS Supports Multiple Logical Views of Data The
User A Logical View Student...
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This note was uploaded on 10/02/2010 for the course ACCT 5457 taught by Professor Polm during the Fall '10 term at Rensselaer Polytechnic Institute.
- Fall '10