PostgreSQL Interview Questions

 What is PostgreSQL?

PostgreSQL, commonly referred to as Postgres, powers applications with its robust and open-source relational database management system. Developers leverage its extensive features, such as Function Overloading and Table Inheritance, to create advanced applications. PostgreSQL seamlessly operates across major operating systems, including Windows, UNIX, macOS, and Linux.

Which data types are used in PostgreSQL?

The following data types are used in PostgreSQL:-
Numeric data type (Integer, Float)
Geometric primitives
Boolean data type
Character data type (varchar, char, text)
Monetary data type
Array
Document data type (JSON, XML, Key-value, etc.)
Date/Time data type
Customization data type (Composite, custom types, etc.)

What is the main query language of PostgreSQL?

SQL or Structured Query Language is the main query language of PostgreSQL.

What do you think is the latest PostgreSQL version in the market?

As of 2022, the latest version of PostgreSQL in the market is PostgreSQL 15. It was launched on 13 October, 2022.

Name the different types of operators that are used in PostgreSQL.

Operators are the special characters or words that are used mainly in the WHERE clause in PostgreSQL. These operators can be used to perform a variety of functions and operations.

The different types of operators that are used in PostgreSQL are as follows:-

Arithmetic operators
Logical operators
Comparison operators
Bitwise operators

What are the differences between PostgreSQL and MongoDB?

PostgreSQL MongoDB
PostgreSQL is a relational database management system. MongoDB is a non-relational database management system.
PostgreSQL was created using the C language. MongoDB was created using the C++ language.
PostgreSQL is object-oriented.MongoDB is document-oriented.
PostgreSQL stores data in the form of different tables. MongoDB stores data in the form of key-value pairs as one record.
PostgreSQL is faster than MongoDB. MongoDB is relatively slower than PostgreSQL.

When should a developer use PostgreSQL?

Developers should choose PostgreSQL when they require a dependable and feature-rich database management system. PostgreSQL is suitable for diverse applications, including web development, data analysis, and enterprise solutions. It provides advanced features like JSON support and geospatial capabilities. With its cross-platform compatibility and active community, developers can rely on PostgreSQL for scaling and achieving optimal performance while managing complex data.

How can you take the backup of a database?

PostgreSQL permits the user to take a backup of the database by using “pg_dump”.
To perform a backup on a plain-text SQL file, login into your database server and implement the following command:
pg_dump database_name > filename.sql
The database can be reconstructed using the commands available in the SQL file.
Another way to backup the database is:
/usr/local/bin/pg_dump mydatabase > mydatabase.pgdump

What are the features of PostgreSQL?

PostgreSQL or Postgres is an object-relational database management system or ORDBMS. Some of its prominent features are as follows:-
Extremely high fault-tolerance
Free to download
Reliable and secure
Robust and powerful
Easy recovery process
Low maintenance cost
Easily compatible with a wide variety of platforms and languages.
High availability
Easy to use