This document discusses database management systems and contains sections on databases, data warehousing, and data mining. It defines what a database and database management system are, and describes their components and advantages. It outlines three database models - hierarchical, network, and relational - and provides more details on the relational model. The document also defines data warehousing and lists its functions and benefits. Finally, it briefly introduces the topic of data mining.
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Mis chapter 4 database management - copy
1. Chapter IV - Data Base Management Systems
4. Data Base Management Systems
Part A ( 1.5 hours) : Database, Data Warehousing
Part B ( 1.5 hours) : Data Mining (6)
2. Chapter III - Data Base Management Systems
Data Base Management Systems
Part A ( 1.5 hours) : Database, Data Warehousing
3. Database
Database:
Database can be defined as
a) “A mechanical or automated, formally defined, centrally controlled
collection of data in an organization”
b) “A collection of data organized to service users or applications at the same
time and managing data so that they appear to be in one location”
Data records are physically organized and stored. It helps in sharing
, availability, evolving, integrity.
Database Management system (DBMS):
DBMS is basically a software system which performs the functions of
defining, Creating, revising and controlling the database.
4. Components and role of DBMS
Components of DBMS:
1. Data Definition Language (DDL): it defines each data as it appears in the database. The
data element is then translated into the format desired or required by the applications
programme.
2. Data Manipulation Language (DML) : it is used by end-users and programmers to
manipulate data in the database. It consists of commands which enables end users and
programmers to extract data from the database to satisfy information requests and
develop applications.
3. Data Dictionary : this is the repository of information about data. It defines each data
elements such as name, description, validation, criteria, security
calculations, sources, keywords search types etc.
Role or Usefulness of data dictionary:
1) It defines data element
2) It helps in scheduling and control
3) Permits users to know which data is available and how can it be obtained
4) It helps to identify organizational data irregularity, if any
5) It acts as glossary (vocabulary) of growing information resources.
6) It serves as an important data management tool
7) It provides report facility.
5. Database Models
There are three types of Database Models:
1. Hierarchical Database Model (HDBM): This is an old model. It follows the structure of the
organization. This represents data in a pyramidal or tree structure. Each record appears to
be like an organizational chart with one top level segment called the root, spreading
downwards into branches. It will have parent-child relationship. It will have one to many
relationship.
2. Network Database Model (NDBM): it has many to many relationship in the database
system. It does not has any specific file structure as such. This is also old model.
3. Relational Database Model (RDBM): This is recent model of database proposed by Dr. E.F.
Codd. It represents the data in database as simple two dimensional tables called Relations.
The table has rows and columns, rows represents individual records and columns represents
attributes of each record.
1. Basic Operations user in RDBMS
a) Select - used to create t the records
b) Project- used by the users to view or creating existing information.
c) Join – used to combine the tables
6. Advantages of DBMS
1. It helps in central controlling and managing of data like access, utilization and
security.
2. It helps in reducing redundancy and inconsistency of data
3. It provides integrity of data
4. It helps in central controlling of data creation thereby elimination of data
confusion
5. It reduces the cost of program development and maintenance
6. It helps in logical view and physical arrangement of file and data and thereby
reduces programme data dependence
7. It provides flexibility (e.g. ad-hoc queries etc.)
8. It increase the access and availability of information.
8. Data Warehouse
Data Warehouse
“Data warehouse is a new technology that provides the users with the tool to store
summarized information from multiple heterogeneous database in a single
repository”
W.H. Inmon Defines
“ a data warehouse is a subject-oriented, integrated, time varying, non-volatile
collection of data in support of the management’s decision making process”
1. subject-oriented (driven)- it is organized the way it is suitable for decision making
and not as per the organization functions
2. Integrated – fully integrated
3. time varying – old data only
4. non-volatile - not changing.
9. Functions and Benefits of Data Warehouse
Functions (what does data warehouse do?)
1. It helps integrate data from heterogeneous sources
2. It consolidates and stores the data in step-by-step fashion
3. It supports management in taking decision.
4. It is a critical component in DSS and EIS
5. It helps in providing summarized, historical and analytical for decision making
6. It optimizes the efforts of consolidation, conversion, transformation and
integration of data
Benefits from Data Warehouse:
1. Time saving for data suppliers and for users
2. More and better information
3. Better decision
4. Improvement of business processes
5. Support for the accomplishment of strategic business objectives.
10. Chapter III - Data Base Management Systems
Part B ( 1.5 hours) : Data Mining (6)
11. Data Mining
• Data mining helps in extracting partners, trends and rules from the data warehouse to
evaluate either predict or scour proposed business strategies which in turn will improve
competitiveness, improves profits and transform business processes.