2 min read

Schema and Instance in DBMS

A database schema is the skeleton structure that represents the logical view of the entire database. A database instance is a state of operational database with data at any given time. It contains a snapshot of the database.
Schema and Instance in DBMS

Instances
Instances are the collection of information stored at a particular moment. The instances can be changed by certain CRUD operations as like addition, deletion of data. It may be noted that any search query will not make any kind of changes in the instances.

Example –
Let’s say a table teacher in our database whose name is School, suppose the table has 20 records so the instance of the database has 20 records for now and tomorrow we are going to add another fifty records so tomorrow the instance have total 100 records. This is called an instance.

Schema
Schema is the overall description of the database. The basic structure of how the data will be stored in the database is called schema.

https://media.geeksforgeeks.org/wp-content/uploads/20200408191704/Untitled-Diagram-130-1.jpg

Example –
Let’s say a table teacher in our database name school, the teacher table require the name, dob, doj in their table so we design a structure as :

Teacher tablename: String doj: date dob: date

Above given is the schema of the table teacher.

Difference between Schema and Instance :

Schema

It is the overall description of the database.

Schema is same for whole database.

Does not change Frequently.

Defines the basic structure of the database i.e how the data will be stored in the database.

Instance

It is the collection of information stored in a database at a particular moment.

Data in instances can be changed using addition, deletion, updation.

Changes Frequently.

It is the set of Information stored at a particular time

https://www.tutorialspoint.com/dbms/images/dbms_schemas.png
Difference between Schema and Instance in DBMS - GeeksforGeeks
A computer science portal for geeks. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions.
https://www.geeksforgeeks.org/difference-between-schema-and-instance-in-dbms/

#DBMS #Schema #Instance #Probyto #ProbytoAI

Subscribe and follow us for latest news in AI and Tech and stay updated!

Facebook: https://facebook.com/probyto
Twitter: https://twitter.com/probyto
LinkedIn: https://linkedin.com/company/probyto
Instagram: https://instagram.com/probyto