DBMS

Table of contents

1. ACID Principles
2. Constraints
3. Joins
4. Normalization and Forms
5. Types of Relations
6. SQL Questions

1. ACID Principles

Set of principles that ensure data integrity and consistency leveraging transactions.

1. Atomicity - Transaction is all-or-nothing
2. Consistency - Transactions are predictable and predefined always
3. Isolation - Concurrent transactions are isolated
4. Durability - A successful transaction is saved in event of failure or reboot

Quick revision on SQL Commands - https://www.programiz.com/sql/commands

Interview SQL Questions Tips

• If question have an aggregator use like, count, sum or avg with group, try to think use of Having clause
• Remember to use LEFT JOIN if null is to be included in join
• If need to include or filter multiple values of a column, like from columns STATUS: confirmed, in-progress, both are to be filtered, consider using CASE WHEN END clause.

2. NoSQL - MongoDB