Notes-Dbms


Some sort of data storage is used by most of the applications.Many different types of data sources,an application can have.A database is a collection of different kinds of data structured into tables consisting of fields and records.To store information,most real world application uses databases.

Database management system

Dbms is a rule or a procedure to manage a database.Database is a collection of 2 or more than two interrelated tables.Table is a collection of related record.Record is a collection of related data.Data means raw facts and figures.

*create
*delete
*insert
*update
*access

Advantages of database management system

*redundancy can be reduced
*inconsistency can be avoided
*better services to the users
*flexibility of the system is improved
*standard can be enforced
*security can be improved
*integrity can be maintained
*facilitates sharing of data
*conflicting requirements can be balanced

Components/Elements of Data

*Data-raw facts and figures

*Relationships-represents a correspondence between the various data elements

*Constraints-predicates that define correct database states

*Schema-describes the organization of data and relationships within the database

Components of Database management system

*hardware-refers to the actual computer system used for keeping and accessing the database

*software-refers to the actual database management system

*data-most important component of dbms from user point of view

*users-each type of user need different software capabilities

*procedures-refers to the instructions and rule that govern the design and use of the database

Database system applications

*banking
*airlines
*universities
*manufacturing
*human resources
*credit card transactions
*finance
*sales
*telecommunication