1. Introduction to Database Management
Chapter 5
Introduction to
Database Management

2. Data Vital organizational resource
Data resource management is a managerial action that applies technology to the task of managing data

3. Data Concepts
Character - a character is a single element of data and can be alphabetic, numeric, or some other ‘legal’ character
Field - A field is a grouping of characters that describes an attribute of and entity
Record - A logical grouping of fields relating to the same entity

4. Data Concepts cont. Records can be fixed length or variable length
File - A group of related records is a file or commonly known as a table. Tables are classified by levels of permanence
transaction - daily sales or production
master - employee_master, item_master
history - usually backups

5. Database
A database is an organized and integrated collection of records
Data in a database is independent of the programs that use the data

6. The Database Management Approach
Foundation of modern data management
Database management approach - data records and objects are consolidated and accessed by multiple application programs
Database Management System - software interface between users and databases - uses DBMS software to create, interrogate, update, and maintain a database to provide information for users

7. Database Management Approach
Three common activities
update and maintain common databases to reflect transactions and organizational data
provide information for end users applications
provide easy interface for ad hoc (on demand) requests, generation of reports, and database interrogation

8. DBMS
A database management system is a set of programs that control four necessary functions in the database world
database development
database interrogation
database maintenance
application development

9. Database Development
Database management application packages allow for the development of databases
Database administrators (DBAs) use a data definition language to design and develop tables, relationships, and a data dictionary
Data dictionary - A catalog or directory of information about the data (meta data)

10. Database Interrogation
Database interrogation (extracting data/information) is accomplished by using a query or a report generator
Query language offer
immediate response to request
no difficult programming

11. Database Interrogation cont
A report generator offers
immediate video or paper response to queries
No difficult programming
Can format or design reports to meet individual needs/preferences

12. SQL and QBE
Structured Query Language - A ‘standardized’ language that allows for simple database interrogation
Basic form for SQL statement is
Select …..
From……
Where…..

13. SQL and QBE
Query By Example - query language similar to SQL except the query is written in the ‘background’ as the user points and clicks
Graphical and Natural queries are essentially point and click utilities that are translated into SQL

14. Database Maintenance
Database maintenance occurs through transaction processing and the ACID functions
A - add
C - change
I - inquiry
D - delete

15. Application Development
Databases are the backbone of system development
A data manipulation language allows for necessary data handling needs

16. Database types There are several major types of databases
operational databases
data warehouses
distributed
external

17. Operational Databases
These databases store data that is necessary for the operations of an organization such as transaction databases, subject area databases
Very important for this type of database to be accurate

18. Data Warehouse
A data warehouse stores data from previous years or time periods that are not necessary for the current operations of an organization
May be subdivided into DATA MARTS that contain certain data elements
Data mining is the process of extracting data, trend analysis, and historical patterns

19. Distributed Databases
Can be copies of organizational databases that reside in different geographical areas, on different servers (for functional areas), or on handheld or labtop devices

20. External Databases
Privately owned online databases usually accessible for a fee
Can be free
Usually associated with Internet

21. Data Resource Management
Data resource management involves several tasks
Database Administration
Data Planning
Data Administration

22. Database Administration
Provides for the development and maintenance of the data dictionary
Monitoring of database and resource performance
Enforcement of standards and security

23. Data Planning Corporate planning and analysis function
Data architecture for firms data needs (must fit within the strategic missions)
Should be a major issue in strategic planning
Long range planning

24. Data Administration
Establishment and enforcement of policies and procedures for managing data resource
Collect, store, and disseminate information in an organizationally standardized manner
Planning and support of data and the establishment of data planning activities
Develop policies and standards for database design

25. Benefits/Limitations
Reduction of replication and redundant data
Data integration
Users can obtain information in more usable form
Programming is simplified
Data integrity and security is ensured

26. Benefits/Limitations
Complexity
Can be very expensive to develop and maintain
Large investment LARGE
More difficult processing procedures (must work through and additional layer of software)

27. Technical Foundations of Database Management
Data resources must be organized in a logical manner
This allows for easy access, efficient processing, quick retrieval of data
Multiple structures………...

28. Hierarchical
Early mainframe packages used the hierarchical structure of database management
Treelike structure
Records are dependent on a root record
Relationships are one to many (only related to the element above it)

29. Network Structure
Able to represent more complicated structures and relationships
Still used in many mainframe packages
Allows for many to many relationships
Access is not one dimensional and can follow many paths

30. Relational Structure Most popular in use today
Used by most micro databases, also used in mini systems and mainframe systems
Data elements stored in tables
Table related through the use of a common field

31. Multidimensional Database Structure
Variation of the relational model
Compact and easy to use
Support OLAP

32. Object Oriented Structure
The key technology of multimedia web-based applications
An object consists of data plus the instructions to be applied
Inheritance is the acceptance of characteristics of other objects

33. Database Access
Databases rely on identifying characteristics called key fields or in the case of older DB types a pointer field
Key field is the primary identifier
Must be unique among all other records

34. Sequential Access
Records are stored in a specific order based on the key field
Sequential processing is fairly fast when dealing with similar records (fixed length)
Requires sorting, indexing, etc.
Best in batch processing situations

35. Direct Access No fixed arrangement of records
Works with immediate response systems
Three ways for direct access to occur
Key transformation
Index
Indexed Sequential access

36. Next Week Chapter 5 data base planning and design
Chapter 6 IS for Business Operations and E-commerce