Category: DBMS

Schema Refinement – Normalization in DBMS

Normalization is a step-by-step process of decomposing a complex relation into a simple and stable data structure. It’s a formal process to achieve a good...

Some other Relational Algebra

Relational Algebra Relational algebra provides a set of operations for the relational model to specify basic data retrieval requests. It is a procedural language for...

Relational algebra in DBMS

What are Relational Models The relational model, also known as RDBMS is the most widely used DBMS model because it is the easiest. The model...

Aggregation

The E-R model has one limitation that it is not possible to express relationships among relationships. In such a situation we use aggregation. Aggregation is...

Extended E-R Features

Superclass and Subclass Some instances of an entity class can include attributes that are not needed in other instances of the same entity class. In...

Types of Relationship: Cardinally

An entity may be associated with one, none, or many occurrences of another entity. In entity-relationship diagrams, the type of relationships are represented as follows:...

Entity-Relationship Model

An er model is a graphical representation of an organization’s data storage requirements. This model is used to design the data elements and relationships for...

Structure of DBMS

The exact architecture or structure of DBMS depends on the operating system on which it has to work because the operating system will provide the...

Important Terminology of DBMS

A database system provides a data definition language to specify the schema and a data manipulation language to express database queries and updates. These two...

Types of DBMS

There are 5 types of DBMS: Relational database Network database Hierarchical database Object-Oriented database NoSQL database Relational Model The relational model, also known as RDBMS...