Node.js Database Integration

Question 1

What is an ORM and why is it used in Node.js applications?

Accepted Answer

Object-Relational Mapping — it lets developers interact with databases using JavaScript objects instead of raw SQL

Answer

Online Resource Manager — a tool for managing cloud resources

Answer

Optimized Runtime Module — a performance enhancement library

Answer

Output Rendering Mechanism — a template engine for HTML

Question 2

What is connection pooling and why is it important?

Accepted Answer

Reusing database connections instead of creating new ones for each query, improving performance

Answer

Combining multiple databases into one large pool

Answer

Pooling connections from multiple servers to one database

Answer

A backup strategy for database connections

Question 3

What is the 'N+1 query problem' in database-backed applications?

Accepted Answer

When fetching related data requires 1 initial query plus N additional queries for each result

Answer

A limitation allowing only N+1 total queries per session

Answer

A security vulnerability allowing injection of N+1 SQL statements

Answer

A database design pattern using N+1 tables

Question 4

What is a database migration in the context of Node.js development?

Accepted Answer

A version-controlled script that modifies the database schema in a predictable, repeatable way

Answer

Moving a database from one server to another

Answer

Converting a SQL database to a NoSQL database

Answer

Backing up data before a server upgrade

Question 5

What is the difference between SQL and NoSQL databases in Node.js applications?

Accepted Answer

SQL databases use structured tables with schemas; NoSQL databases use flexible document, key-value, or graph structures

Answer

SQL databases are faster; NoSQL databases are more reliable

Answer

There is no practical difference for Node.js applications

Answer

SQL databases only work with Java; NoSQL only works with Node.js

Question 6

What is Mongoose in the Node.js ecosystem?

Accepted Answer

An ODM (Object Document Mapper) for MongoDB that provides schema validation and data modeling

Answer

A testing framework for Node.js applications

Answer

A task scheduler for running cron jobs

Answer

A CSS preprocessing library for server-side rendering