Assignment on dbms

Amrapali Institute

Submitted to: Submitted by:
Monika Gupta SUNDEEP LOHANI
Lecturer MBA Sec B (2nd sem)
AIMCA

 Purpose of Database system
 Advantages of DBMS
 Data Manipulation Language
 SQL
 Data Models
 Database Administrator
 Database Users
 Database Management System

 Collection of interrelated data
 Set of programs to access the data
 DBMS contains information about a particular enterprise
 DBMS provides an environment that is both convenient
and efficient to use.
 Database Applications:
 Banking: all transactions
 Airlines: reservations, schedules
 Universities: registration, grades
 Sales: customers, products, purchases
 Manufacturing: production, inventory, orders, supply chain
 Human resources: employee records, salaries, tax deductions
 Databases touch all aspects of our lives

 In the early days, database applications
were built on top of file systems
 Drawbacks of using file systems to store
data:
 Data redundancy and inconsistency
 Multiple file formats, duplication of information in different files
 Difficulty in accessing data
 Need to write a new program to carry out each new task
 Data isolation — multiple files and formats

 Data consistency and integrity
 Application program independence
 Data sharing
 Backup and recovery
 Security and privacy
 Multiple views of data

 Language for accessing and manipulating the
data organized by the appropriate data model
 DML also known as query language

 Two classes of languages

 Procedural.
 Nonprocedural.

 SQL is the most widely used query language

 SQL: widely used non-procedural language
 E.g. find the name of the customer with customer-id 192-83-
7465
select customer.customer-name
from customer
where customer.customer-id = ‘192-83-7465’
 E.g. find the balances of all accounts held by the customer with
customer-id 192-83-7465
select account.balance
from depositor, account
where depositor.customer-id = ‘192-83-7465’ and
depositor.account-number = account.account-
number
 Application programs generally access databases
through one of
 Language extensions to allow embedded SQL
 Application program interface (e.g. ODBC/JDBC) which allow
SQL queries to be sent to a database

A collection of tools for describing
 data
 data relationships
 data semantics
 data constraints
 Entity-Relationship model
 Relational
model
 Other models:
 object-oriented model
 semi-structured data models
 Older models: network model and hierarchical model

 Example of schema in the entity-
relationship model

 E-R model of real world
 Entities (objects)
 E.g. customers, accounts, bank branch
 Relationships between entities
 E.g. Account A-101 is held by customer Johnson
 Relationship set depositor associates customers with
accounts
 Widely used for database design
 Database design in E-R model usually
converted to design in the relational model
(coming up next) which is used for storage and
processing

Customer- customer- customer- customer- account-
id name street city number

192-83-7465 SONU North Haldwani A-101

019-28-3746 SURAJ Main Rudrapur A-215

192-83-7465 PERVZ North Pauri A-201

321-12-3123 PREM East Haridwar A-217

019-28-3746 SHIVAM Main Rudrapur A-201

 Coordinates all the activities of the
database system; the database
administrator has a good understanding of
the enterprise’s information resources and
needs.
 Database administrator's duties include:
 Schema definition
 Storage structure and access method definition
 Schema and physical organization modification
 Granting user authority to access the database
 Specifying integrity constraints
 Acting as liaison with users
 Monitoring performance and responding to
changes in requirements

 Users are differentiated by the way they expect to
interact with the system
 Application programmers – interact with system through
DML calls
 Sophisticated users – form requests in a database query
language
 Specialized users – write specialized database
applications that do not fit into the traditional data
processing framework
 Naïve users – invoke one of the permanent application
programs that have been written previously
 E.g. people accessing database over the web, bank tellers,
clerical staff

Assignment on dbms

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