HRMantra Software Interview Questions and Answers

Joins are SQL operations that combine rows from two or more tables based on related columns.

• INNER JOIN: Returns records with matching values in both tables. Example: SELECT * FROM A INNER JOIN B ON A.id = B.id;

• LEFT JOIN: Returns all records from the left table and matched records from the right table. Example: SELECT * FROM A LEFT JOIN B ON A.id = B.id;

• RIGHT JOIN: Returns all records from the right table and matched re...read more

A materialized view is a database object that stores the result of a query for faster access and improved performance.

• Materialized views store data physically, unlike regular views which are virtual.

• They can improve query performance by pre-computing expensive joins and aggregations.

• Materialized views can be refreshed manually or automatically to keep data up-to-date.

• Example: A materialized view can aggregate sales dat...read more