1. Data resource management
Unit 5
Organizing Data and Information

2. Learning Outcomes Understand records in a database
Understand components of a DBMS
Identify database models and types
Define
Database concepts
Structures & record keeping
Data languages
Development tools
Security and admin
Principles of Information Systems, Eighth Edition

3. Data Management
Without data and the ability to process it, an organization could not successfully complete most business activities
Data consists of raw facts
To transform data into useful information, it must first be organized in a meaningful way
Principles of Information Systems, Eighth Edition

4. The Hierarchy of Data Character: a group of 8bits forming a byte
Can be an uppercase letter, lowercase letter, numeric digit, or special symbol
Field: group of characters, typically a name, number, or combination of characters that describes an aspect of a business object or activity
Record: collection of related data fields
File: collection of related records
Database: collection of integrated and related files
Principles of Information Systems, Eighth Edition

5. The Hierarchy of Data (continued)
Figure 5.1: The Hierarchy of Data

6. Definitions
Database management system (DBMS): group of tools that support database management and it’d performance in an organisation
Data independence: data is independent from the program that creates it. This means programs and data developed in for 1 app are compatible with programs and data from another app.
Data redundancy: duplication of data in separate files – can lead to inconsistency.
Principles of Information Systems, Eighth Edition

7. Database Approach
Principles of Information Systems, Eighth Edition

8. Keys*
Key: field or set of fields in a record that is used to identify the record
Primary key: field or set of fields that uniquely identifies the record
Foreign Key: A non-primary key attribute in the table that is a primary key in the other table.
Principles of Information Systems, Eighth Edition

9. Data Views * Physical View: Where is data stored physically?
Drive, disk, surface, track, sector, Record
Tape, block, record number (key)
Used by programmers
Logical View: What data is needed? How do users need the data to be arranged?
Organize factors into tables for application use
Provide a way for tables to cross-reference *
Principles of Information Systems, Eighth Edition

10. Accessing File Structures
Sequential file structure e.g. payroll
Data is stored and accessed in a sequence according to a key field
Good for periodic processing of a large volume of data, but updating with new transactions can be troublesome
Direct file structure e.g. reservations
Data stored randomly and accessed directly using an index of keys and related storage addresses.
Indexed Sequential file structure
Records stored sequentially on direct access medium (e.g. hdd) with address for each record.
Index keeps track of addresses for speed. Sequential access for large amounts of data
O’BRIEN

11. Record Processing Online vrs Batch
Principles of Information Systems, Eighth Edition

12. DBMS Components
Data dictionary: Stores definitions of data elements, and data characteristics e.g. data type, amount of storage: txt 30
Data Languages:
Data definition language: Specifies content and structure of database and defines each data element e.g keys, relationship
Data manipulation language: allows users to access and change data and produce reports. E.g. SQL, QBE
Application Development Tools: Programs to develop apps to use the database, e.g. CASE tools
Software Security: protect database from hacking & unauthorised access.
Archiving, backup & recovery systems: in case database is lost/crashes, it can be recovered from backups or archives.
Report Writers: tools to specify a report format for retrieving data
Principles of Information Systems, Eighth Edition

13. Sample data dictionary report
Principles of Information Systems, Eighth Edition

14. Structured Query Language (SQL)
Examples of SQL Commands
Principles of Information Systems, Eighth Edition

15. Database Models Hierarchical Network Relational Multidimensional
Object-oriented
Object-relational
Principles of Information Systems, Eighth Edition

16. Hierarchical Database Model
May have more than one offspring, but only one parent
Treelike
One-to-many relationship
Used for structured, routine types of transaction processing
Laudon

17. Network database model
More complex
Many-to-many relationship
More flexible but doesn’t support ad hoc requests well
Principles of Information Systems, Eighth Edition

18. Relational Database Model
Data elements stored in simple tables
Can link data elements from various tables
Very supportive of ad hoc requests but slower at processing large amounts of data than hierarchical or network models
Principles of Information Systems, Eighth Edition

19. The Relational Database Model
Principles of Information Systems, Eighth Edition

20. The Relational Database Model (continued)
Principles of Information Systems, Eighth Edition

21. The Relational Database Model (continued)
Principles of Information Systems, Eighth Edition

22. Multidimensional DB model
A variation of the relational model
Cubes of data and cubes within cubes
Popular for online analytical processing (OLAP) applications
Principles of Information Systems, Eighth Edition

23. Object-oriented DB Model
Data descriptions & procedures that act on data are grouped together.
Key technology of multimedia web-based applications
Good for complex, high-volume applications
Can store more data types
Objects can be reused
Faster data accessed
Principles of Information Systems, Eighth Edition

24. Object-Relational DB Model
Combines features of object-oriented and relational databases
Standard relational database with facilities for new data types (e.g. video) and operations to be added.
Principles of Information Systems, Eighth Edition

25. Types of Databases Operational DB – to support business operations
Analytical BD – Summarized data 4 analysis
Data Warehouse*
Distributed - data may be spread across several smaller databases in different locations .
End-user –developed by managers and other users on their own PCs
External/on-line – pay for access to external statistical online databases
Principles of Information Systems, Eighth Edition

26. Data Warehouses, Data Marts, and Data Mining
Data warehouse: Logical collection of data gathered from many operational DBs to support business and decision making.
Data mart: subset of a data warehouse
Data mining: automated discovery of patterns, trends and rules from data in data warehouse to predict business strategy.
Principles of Information Systems, Eighth Edition

27. Data Warehouses, Data Marts, and Data Mining (continued)
Figure 5.17: Elements of a Data Warehouse
Principles of Information Systems, Eighth Edition

28. Advantages of DBMSs Data sharing
Reduced data redundancy (no duplicates)
Improved data consistency (more integrity)
Data independence (data independent of the application using it.)
Improved data admin & control – better overall protection
More emphasis on data as a resource
Principles of Information Systems, Eighth Edition

29. Problems with DBMSs
Concurrency problem – data used at same time - lock
Resource problems – costly initially
Security problems - cos data all in one place
Principles of Information Systems, Eighth Edition