ExpertusONE Interview Questions and Answers

DB transaction is a unit of work performed on a database that must be completed as a whole or not at all.

• A DB transaction ensures data integrity by either committing all changes or rolling back if an error occurs.

• Transactions typically include multiple database operations like inserts, updates, and deletes.

• ACID properties (Atomicity, Consistency, Isolation, Durability) are maintained in a DB transaction.

• Example: transf...read more

Optimizing SQL queries involves using indexes, minimizing data retrieval, and avoiding unnecessary joins.

• Use indexes on columns frequently used in WHERE clauses

• Minimize data retrieval by selecting only necessary columns

• Avoid unnecessary joins by using subqueries or temporary tables