1. 3/6: Data Management, pt. 2 Refresh your memory Relational Data Model
Hierarchical & Network Data Model
Object-oriented DBMS
Designing & Distributing a Database
Trends
Multidimensional Data Analysis, OLAP
Hypermedia
Linking databases to the web
Data Warehousing & Data Marts
Who deals with databases?
Users & Administrators

2. Database Management System
Software to create & maintain data
Enables business applications to extract data
Independent of specific computer programs

3. The 3 Key Components of a DBMS
Data definition language:
Defines data elements in database
Data manipulation language:
Manipulates data for applications
SQL: Structured Query Language
Emerging standard data manipulation language for relational databases
Data dictionary:
Formal definitions of all variables in database; Controls variety of database contents

4. Types of Databases: Relational
Flexible, common format today.
Data in table format
Relation: table (sometimes called a file)
Tuple: row (record) in table
Field: column (attribute) in table

5. Relational DBs: Possible Relationships
One-to-one
One-to-many
Many-to-many
STUDENT ID
CLASS
STUDENT A B C
CLASS 1 2
STUDENT A B C

6. Hierarchical Data Models
Older, traditional system
Top-level segment: Root.
Parent-child relationships (one-to-many)
ROOT
FIRST CHILD
2nd CHILD
Ratings
Salary
Compensation
Job
Assignments
Pension
Insurance
Health
Benefits
Employer

7. Network Data Models A variation of the hierarchical data model
Allows for many-to-many relationships
STUDENT A B C
CLASS 1 2

8. Goodbye, Hierarchical & Network
Rarely, the network nor the hierarchical models are used for new databases now: they are legacy systems.
Less flexible than relational DBMS
Do not support ad-hoc queries
Intensive programming required for changes to reports, queries, etc.

9. Object-Oriented DBMS
Improvement over traditional DBMS to handle graphics, multimedia, etc.
Variation: object-relational DBMS
Hybrid of OODBMS & Relational DBMS

10. Designing a Database Conceptual (logical) design & physical design
Abstract model of database from business perspective
Deciding which data to include, exclude
What to use as the key field?
Normalization: creating small stable data structures from complex data
Critical task: avoid redundancy.
Choosing hardware & software for database

11. Designing a Database Conceptual (logical) design
Entity-relationship diagram
Illustrates relationship between various entities in a database 1 M
ORDER
CAN HAVE
PART
SUPPLIER
ORDER: #, DATE,
PART #, QUANTITY
PART: #,
DESCRIPTION,
UNIT PRICE,
SUPPLIER #
SUPPLIER: #,
NAME, ADDRESS

12. Distributing Databases: 2 Ways
PARTITIONED:
remote CPUs (connected to host) have files unique to that site, e.g., records on local customers
DUPLICATE:
each remote CPU has copies of common files, e.g., layouts for standard reports and forms
Why distribute a database?
Reduce vulnerability
Increase service & responsiveness
Can run on smaller, cheaper computers

13. Trends in DBMS Multidimensional Data Analysis Hypermedia Databases
Comparing more than two aspects of data
Synonym: On-line Analytical Processing (OLAP)
Hypermedia Databases
Storage and indexing of images, videos, sounds, multimedia, etc.
Linking databases to the web

14. Data Warehouses & Data Marts
Organization’s electronic library stores consolidated current & historic data for management reporting & analysis
Provides a range of ad hoc & standardized query tools, analytical tools, and graphical outputs.
Data Marts: smaller, specialized versions of the data warehouse customized for audience or task.

15. Data Warehouses & Data Marts

16. Who Deals With Databases?
Users
Administrators
Define & organize database structure and content
Develop security procedures
Develop database documentation
Maintain DBMS