Define RDBMS. Name any two RDBMS software.

Q. Define RDBMS. Name any two RDBMS software.

Answer :-

RDBMS :- Relational database management system.

It is a more scientific and stable model network model since there are no pointers involved with the records and in case of any fault or error, these pointers may result in inconsistency among the records and can lead to reduced data integrity. In this model, data is organized in two-dimensional tables called relations. The table relations are related to each other. A relational database is based on this relational model developed by E.R Codd. In this type of database, the data and relations between them are organized into tables, having logically related records containing the same fields. The contents of a table or relation can be permanently saved for future use. Thus, this model is simple and has all the properties and capabilities required to process data with storage efficiency.

RDBMS Software :-

1. MySQL
2. Oracle

A relational model consists of a collection of tables, each of which is assigned a unique name, Le, it represents the database as a collection of relations or tables, Characteristics of a relational database are:

1. Data is conceptually represented as an orderly arrangement of data into rows and columns, termed a relation.
2. Each relation is represented as a table. 3. Columns described in a table are the attributes that belong to an entity which is modelled as a table.
4. Every row in a table represents a single entity.
5. All the values in a relation are scalar, ie, at any given row or column position, there is one and only one value. 6. All operations are performed on the entire relation and the result is an entire relation.

Advantages of a relational model are as follows:

1. A relational model provides structural independence by using independent tables.
2. Changes made in the table structure do not affect the data access or other application programs.
3. It is represented in the form of tables; so, it is simple and easier to understand. 4. Tabular view also provides easier database design, use, implementation and management
5. Built-in query support based on SQL is provided by RDBMS (Relational Database Management System).
6. Data organization and manipulation is easy, flexible and faster.
7. Powerful structure designing and processing capabilities of RDBMS isolate the end-user from physical-level details and, thus, improve implementation and management simplicity 8. Mathematical operations can be successfully carried out using RDBMS.

The limitations of relational model are:
1. RDBMS incurs hardware and system software overheads.
2. The size of the database becomes very large.