Extension : It is the number of tuples present in a table at any instance. This is time dependent. Intension : It is a constant value that gives the name, structure of the table and the constraints laid on it.

What are extensions in database?

Database files store data in a structured format, organized into tables and fields. Common database file extensions include . DB, . ACCDB, . NSF, and .

What is the extension of relational database?

RDBMS is an extension of that acronym that is sometimes used when the underlying database is relational.

Why instance is called extension in database?

An instance is the information collected in a database at some specific moment, and it is also known as state or extension. It is a snapshot where the current state or occurrence of a database is framed at that moment.

What are different data models in DBMS?

Some of the Data Models in DBMS are:
Hierarchical Model.Network Model.Entity-Relationship Model.Relational Model.Object-Oriented Data Model.Object-Relational Data Model.Flat Data Model.Semi-Structured Data Model.

What is the concept of extension?

– Extension is a process of working with rural people in order to improve their livelihoods. This involves helping farmers to improve the productivity of their agriculture and also developing their abilities to direct their own future development.

What is ternary relationship in DBMS?

In the Ternary relationship, there are three types of entity associates. So, we can say that a Ternary relationship exists when there are three types of entity and we call them a degree of relationship is 3. So, here three entity types are associating we can say it is a ternary relationship.

What is difference between DBMS and Rdbms?

Database Management System (DBMS) is a software that is used to define, create and maintain a database and provides controlled access to the data. Relational Database Management System (RDBMS) is an advanced version of a DBMS. DBMS stores data as file. RDBMS stores data in tabular form.

What is degree and cardinality in mysql?

Degree is the total number of attributes/fileds of a relation/table and cardinality is total number of tuples/rows of relation/table.

What is difference between instance and schema?

The main difference between schema and instance is that schema is a structural view of the database, while the instance is the data stored in a database at a particular moment of time. The database is a collection of organized data.

What are instances in DBMS?

The situation where a data or information is stored in the database at a particular moment of time is called an instance. An instance is also called a current state or database state. Every time we can insert, modify, or delete the value of a data item in a record.

What is the difference between schema and Subschema?

The schema is a complete description of a database, including the names and descriptions of all areas, records, elements, and sets. A subschema provides a view of the database as seen by an application program.

What are the 4 types of models?

Since different models serve different purposes, a classification of models can be useful for selecting the right type of model for the intended purpose and scope.
Formal versus Informal Models. Physical Models versus Abstract Models. Descriptive Models. Analytical Models. Hybrid Descriptive and Analytical Models.

What are the 4 types of database model?

Types of database models

Hierarchical database model. Relational model. Network model. Object-oriented database model.

What are the three main types of models?

Contemporary scientific practice employs at least three major categories of models: concrete models, mathematical models, and computational models.