Chapter 1 Data base System Concepts Data Modeling

Chapter 1 Data base System Concepts & Data Modeling

Data

File Systems

Data Base Management System n DBMS is a collection of interrelated data and set of programs to access those data.

Various Data Base Mgt Systems

Disadvantages of File Systems Data Redundancy and Inconsistency n Data Isolation n Integrity Problems n No Transaction support n No data sharing n Security Problems n

Front End

Back End

Data Abstraction

Data Abstraction(Physical Level) Rollno Name Marks

Data Abstraction(Logical Level) Rollno Name Marks 1 Misha 22 2 Minu 34

Data Abstraction(View Level) Rollno Name 1 Misha 2 Minu

Instance n Data base changes over time as information is deleted and inserted. The collection of information stored in the database at a particular moment is called an Instance of Database. n Insert into student values(1, ’misha’, 99)

Schema n The overall design of the database is called as the database schema.

Schema

Database Languages SQL DDL DML CREATE INSERT DROP DELETE ALTER UPDATE TRUNCATE RENAME SELECT

Data Defination Language Create Table n Alter Table n Truncate n Rename table n Drop table n

Data Manipulation Language Insert n Select n Update n Delete n

Data. BASE USER’S n Application Programmer’s

Naïve User’s

Sophisticated User’s

Specialized User’s

Functions of DBA Schema Definition n Storage Structure and access method definition n Granting of Authorization for data access n Routine Maintenance. n Performance Tuning n

Two Tier Architecture

Three Tier Architecture

Non Client Server