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Database Management
System (DBMS)
Introductory Concepts
Week-1
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Database Management System
Topics Overview
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DATA & INFORMATION
FILE-BASED SYSTEMS
DATABASE
DATABASE MANAGEMENT SYSTEMS (DBMS)
DB LANGUAGES
DB USERS
DB SCHEMAS
DBMS FACILTIES
DATA DICTONARY
HISTORY – DATABASE MODELS
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Data and Information
What are Data?
Data are raw facts or figures.
What is Information ?
Information is processed data which gives meaning
to the user.
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Information is produced by processing data.
Information is used to give the meaning of data.
Good, relevant, and timely information is the key to
good decision making.
Good decision making is the key to organizational
success.
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What is a File Base System ?
It is the storage area in a computer system
where user stores programs and data
permanently.
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User programs and data are stored in
individual files in the file system.
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A file is a collection of data or program
instructions.
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Examples of Files
a file named “students" might contain information about the
different students in the college.
a file named “teachers" might contain information about the
different teachers working in the college.
a file named "Aircraft" might contain information about the
different types of aircraft used by a particular airline company.
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LIMITATIONS OF FILE-BASE SYSTEM
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REDUNDANCY ( DUPLICATION )
The use of individual data files lead to situations in
which an organization maintains many copies of the
same basic information.
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INCONSISTENCY (NOT CORRECT)
SEPARATION AND ISOLATION
NO SHARING OF DATA
PROGRAM & DATA DEPENDENCE
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DATABASE
Definition
A DATABASE IS A COLLECTION OF SELF-DESCRIBING,
INTEGRATED AND ORGANISED DATA.
(It is a collection of related files)
Examples of Manual System:
 DICTIONARY (English Words - Meaning)
 NEWSPAPER
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BOOK INDEX
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DATABASE MANAGEMENT SYSTEM (DBMS)
Definition
A DBMS is a set of programs that allow users to
create the database and also allow to access, modify,
print, add and delete the data from a database.
Different DBMS Software are :
ORACLE
ACCESS
SQL SERVER
DB2
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Examples of Database Applications:
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Student Registration System
Computerized Library Systems
Stock/Inventory Management Systems
Flight Reservation Systems
Automated teller machines
Hotel Management System
Hospital Management System
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ADVANTAGES OF DATABASE
MANAGEMENT SYSTEMS
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CONTROL REDUNDANCY
CONSISTENCY
INTEGRITY
SECURITY
DATA SHARING
EASY MAINTENANCE
MORE INFORMATION
BACKUP & RECOVERY
DATA STANDARD
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Database vs. File Systems
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USERS/ROLES IN DATABASE
ENVIRONMENT
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DATABASE DESIGNER
 designing logical & physical database
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APPLICATION PROGRAMMER
 writing programs to create the database using DBMS software
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DATA ADMINISTRATOR & DATABASE ADMINISTRATOR
 doing database administration works
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END-USER
 users of the system
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Duties or Responsibilities of Database Administrator
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Makes policy and strategic decisions.
E.g.
Purpose of the database, which data processing is done
by the DBMS?
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Defining Security & Integrity Rules
E.g.
Create user-ids and passwords
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Defines Backup procedures
E.g. When to take backup and what data is to be backed-up?
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Monitoring performance and responding to changing requirements.
E.g. Is the query fast enough? Does the report satisfy the mangers?
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Defines the conceptual schema
E.g. Design the schema based on users’ views
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Defines the internal schema
E.g. How should the schema be implemented – Relational DBMS?
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LIMITATIONS OF DBMS
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COMPLEXITY
SIZE
COST
• SOFTWARE
• HARDWARE
• CONVERSION
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PERFORMANCE
VULNERABILITY
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Database Languages
A special database language called (SQL) Structured Query Language
is used to create the database, query the database, process the data
and maintain the data base.
SQL includes three types of languages:
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DATA DEFINITION LANGUAGE (DDL)
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DATA MANIPULATION LANGUAGE (DML)
• Procedural DML
• Non-procedural DML
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DATA CONTROL LANGUAGE (DCL)
Also another language called Fourth-Generation Language used for
creating Forms, reports, graphics, & applications.
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Three-Level of Database (in ANSI-SPARC
Architecture )
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External
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Conceptual
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User's view
Organization view
Constraints, semantic, security, &
integrity
Internal
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Physical presentation
Storage, security, & encryption
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Database Schemas
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The over all design of the database is called
database schema.
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The user’s view of database is called
subschema or external schema.
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The process of designing the database
using the models based on user’s view is
called conceptual schema.
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The physical implementation of database is
called internal schema.
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DATABASE MANAGEMENT SYSTEM
(DBMS) FACILITIES
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SECURITY SYSTEM
INTEGRITY SYSTEM
BACKUP & RECOVERY SYSTEM
QUERY LANGUAGES
CATALOG MANAGEMENT
APPLICATION GENERATOR
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SYSTEM CATALOG
Data Dictionary
It is a data about data. It contains complete
information about the database such as what
are the tables, data items, constraints, grants,
users, etc.
Common Eg : File Manager in windows
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HISTORY OF DBMS - Database Models
• FIRST GENERATION
– HIERARCHICAL MODEL
• INFORMATION MANAGEMENT SYSTEM (IMS)
– NETWORK MODEL
• CONFERENCE ON DATA SYSTEM LANGUAGES
(CODASYL)
• DATA BASE TASK GROUP (DBTG)
• SECOND GENERATION
– RELATIONAL MODEL
• DB2, ORACLE
• THIRD GENERATION
– OBJECT-RELATIONAL DATA MODEL
– OBJECTED-ORIENTED DATA MODEL
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