This chapter discusses databases and database management systems (DBMS). It explains that a database is a structured collection of records or data that is stored so it can be easily accessed, managed, and updated. A DBMS is a program that creates and maintains databases. The chapter compares enterprise and personal DBMS and describes how forms, reports, queries and other applications interface with databases. It also provides an example of how this information could help Dee explain her need for a database to her network administrators.

1. 5장
Database Processing

2. This Could Happen to You
• Dee selected Movable Type
application program
• Needs database program to store blog
– Consultant suggested MySQL
– Network standardized on Oracle
• May not be able to run Movable Type
• Will require revision of labor estimates
– IT resists installing MySQL
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3. Q1: What Is the Purpose of a
Database?
• To organize and keep track of things
• Spreadsheets do that too
– Keep lists of single concept
– Example: Student test scores in a course
• Databases
– Keep lists that involve multiple themes/concepts
– Examples: Student grades, grades for all courses in a
department, courses offered in all departments, faculty
records, and so on
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4. Q2: What Does a Database Contain?
• Self-describing collection of integrated records
• Hierarchy of data elements
– Bytes/data are grouped into columns/fields
– Columns grouped into rows/records
– Rows are grouped into tables/files
• Collection of tables plus relationships among rows
– Also includes “metadata”
• Describes the structure of the database
• A database is a structured collection of records or
data that is stored in a computer system so that a
computer program or person using a query
language can consult it to answer queries.
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5. Student Table
(also called a file)
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6. Relationships Among Records
• Values in one table may relate to rows/records in
other tables
• Keys
– Column(s) that identify unique row in table
– Each table has a key
• Foreign keys
– Keys of a different table than the one in which they reside
• Relational databases
– Databases using tables, keys, and foreign keys
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7. Example of Relationships
Among Rows
Figure 5-6
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8. Metadata
• Database is self-describing
– Contains descriptions of its data
• Metadata
– Data that describe data
– Make databases more useful
– Make databases easier to use
• Describe data
– Data type
– Field name
– Field properties
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9. Q3: What Is a DBMS and
What Does It Do?
• Database management system (DBMS)
– Program that creates, processes, and administers database
– Usually licensed from vendors
– Examples: Microsoft Access, Oracle, MySQL, DB2
• DBMS and database are two different things
– Database is a structured collection of records or data that is
stored in a computer system so that a computer program or
person using a query language can consult it to answer
queries. The computer program used to manage and query
a database is known as a database management system
(DBMS).
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10. Components of a Database
Application System
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11. Database Management Systems
• DBMS used to create tables, relationships in
databases
• Applications use DBMS to read, insert,
modify, and delete data
– Structured Query Language (SQL)
• International standard for processing database
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12. Creating the Database and Its Structure
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13. Processing the Database
• Four DBMS operations
1. Read data
2. Insert data
3. Modify data
4. Delete data
• Structured Query Language
INSERT INTO Student
([Student Number], [Student Name], HW1, HW2,
MidTerm)
VALUES
(1000, ‘Franklin, Benjamin’, 90, 95, 100)
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14. Administering the Database
• DBMS security features used to set up user
accounts, passwords, permissions,
processing limits
– Permissions – data access rights for specific users
or groups of users
• Database backup and replication, adding
structures, removing unneeded data
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15. Q4: What Is a Database Application?
• Collection of forms, reports, queries, and
application programs that process a database
• Databases can have multiple applications
• Applications can have multiple users
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16. Use of Multiple Database Applications
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17. Forms, Reports, and Queries
• Forms
– Used to read, insert, modify, and delete data
• Reports
– Show data in structured context
– May compute values
• Queries
– Are a means of getting answers from database
data
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18. Database Application Programs
• Application programs
– Process logic specific to a business need
– May enable database processing over Internet
to:
• Serve as intermediary between Web server and
database
• Respond to events
• Read, insert, modify, delete data
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19. Example of a Query
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20. Q5: What Is the Difference Between an
Enterprise DBMS and a Personal DBMS?
• Enterprise DBMS
– Processes large organizational and workgroup
databases
– Supports many users (thousands plus)
– Examples: DB2, SQL Server, Oracle, DB2
• Personal DBMS
– Designed for smaller, simpler database
applications
– Supports fewer than 100 users
– Examples: Access, dBase, FoxPro, Paradox, R-
Base
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21. Personal Database System
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22. How Does the Knowledge in This
Chapter Help Dee and You?
Helps to:
• Know what a DBMS is and what roles it can play
• Understand the diagram of the role of the DBMS for
her blog
– System is isolated from rest of databases
– Uses MySQL as part of functionality of her application
• Be better able to explain what she wants, and that it is
no threat or exception to Oracle standard
• Maybe avoid hiring a consultant
Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 5-22

23. Role of DBMS for Dee’s Blog
Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 5-23

24. Guide: No, Thanks, I’ll Use a
Spreadsheet
• Databases take time to build
• Complicated to operate
– May require use of multiple applications
• Need IS people to create it and keep it
running
• Will share data that you may not want to
expose
• Spreadsheets may be a better option in some
cases
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