Full-Stack Development Database Design & Management 3

Question 1

What is the purpose of database connection pooling in full-stack applications?

Accepted Answer

To reuse existing database connections instead of creating a new one for each request

Answer

To encrypt connections between the app and database

Answer

To replicate data across multiple databases simultaneously

Answer

To compress query results before sending them to the application

Question 2

Which SQL command is used to remove all rows from a table without logging individual row deletions, making it faster than DELETE?

Accepted Answer

TRUNCATE TABLE

Answer

DROP TABLE

Answer

DELETE FROM

Answer

REMOVE FROM

Question 3

In MongoDB, what is the equivalent of a table in a relational database?

Accepted Answer

Collection

Answer

Document

Answer

Schema

Answer

Index

Question 4

What does the N+1 query problem refer to in ORM usage?

Accepted Answer

Executing one query to fetch a list and then N additional queries to fetch related data for each item

Answer

Using more than N indexes on a single table

Answer

Running queries that return N+1 rows more than expected

Answer

Having N+1 database connections open simultaneously

Question 5

Which database migration strategy involves making all schema changes backward-compatible before deploying new application code?

Accepted Answer

Expand and Contract pattern

Answer

Big Bang migration

Answer

Blue-Green database migration

Answer

Shadow table migration

Question 6

What is a database view?

Accepted Answer

A virtual table defined by a SQL query that can be queried like a regular table

Answer

A cached snapshot of query results stored on disk

Answer

A read-only replica of the main database

Answer

A visual diagram of the database schema

Question 7

When designing a many-to-many relationship in a relational database, what is the standard approach?

Accepted Answer

Create a junction (bridge) table with foreign keys to both related tables

Answer

Store a JSON array of related IDs in one of the tables

Answer

Duplicate rows in both tables to represent each relationship

Answer

Use a BLOB column to store serialized relationship data