Database is a collection of related information . Database is a self-descrbing and organized collection of integrated records . A database is a single organized collection of structured data with a minimum of duplication of data items so as to provide a consistent and controlled pool of data .
Database Management System(DBMS):
DBMS is a set of programs that process, define and administers database and its applications. A database refers to integrated computer files that are managed by a set of integrated software called a database management system or DBMS.
A DBMS concedntrates on the management and control of a shared data resource. Applications now retrieve and store data via the DBMS. Application program reqests are handled by the DBMS that determines data sharing and protects data unauthorized access.
Relational Database Management System(RDBMS) :
RDBMS is a softweare that manages data in more than one file at onec, and these files are treated as tables with rows and columns rather than as lists of records .
A relational DBMS allows the user to update records, provides an inquiry capability against a given label, and can merge two or more tables to form one relation based on the user's request. It develops new relations on user command.
An important aspect of the relational model is the concept ofr key. A primary Key is an attribute or attributes that uniquely identifies a record. No two records may have the some key. It our example, employee ID could be chosen ad a primary key . It uniquely identifies an employee.
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