Introduction to Database Management Systems
A scheme of grouping a set of integrated data files together is called as database. A database is a collection of information can easily be accessed, managed and updated.
Database Management System
A Database Management System (DBMS) is a set of prewritten programs that are used to store, update and retrieve a database.
Some of the popular DBMS are DB2 (from IBM), SQL Server (from Microsoft), Oracle (from Oracle).
Advantages of Database Management
- Data redundancy: The data duplication in DBMS is minimal.
- Data consistency: DBMS make sure that data in a database are consistent.
- Security: DBMS easily and efficiently handles security and protection of sensitive information.
- Quicker response: It facilitates quicker responses to queries and also reduces a lot of unnecessary programming effort.
- Data independence: DBMS frees user from knowing the physical details of data. The users need not worry about the size, layout and storage of data.
- Data sharing: DBMS allows easy data sharing.
- Transactions: Transaction helps to maintain data integrity.
- DBMS makes sure that two or more users can access the same database at the same time and that the data would remain in the correct state.
Database model defines the way data is organized in and accessible from DBMS. Primarily there are three DBMS models:
- Hierarchical model
- Network model
- Relational model
Relation model is also known as RDBMS. It is the most popular DBMS model.