POSTGRESQL DATABASE INTERVIEW QUESTIONS

What does the EXISTS keyword do in a PostgreSQL query?

How can you use the ANY keyword in a PostgreSQL query?

Explain the ALL keyword and its use in PostgreSQL.

What is the difference between EXISTS and IN in PostgreSQL?

Can you use the ANY keyword with comparison operators other than =? Give an example.

Describe a scenario where using ALL would be more appropriate than ANY in a PostgreSQL query.

Explain how EXISTS can be used to improve the performance of a query compared to IN when dealing with large datasets.

How does the ANY keyword work with subqueries that return multiple columns?

Discuss the use of EXISTS in a correlated subquery and its impact on query performance.

How would you optimize a query using EXISTS, ANY, or ALL when dealing with complex join operations in PostgreSQL, considering ORACLE compatibility?