NoSQL database types (document, key-value, column, graph) in DBMS Theory - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Document NoSQL database?

A Document NoSQL database stores data as documents, usually in JSON or BSON format. Each document contains key-value pairs and can have different structures. It is like storing data in flexible folders where each folder can have different files.

beginner

How does a Key-Value NoSQL database work?

A Key-Value NoSQL database stores data as pairs of keys and values. It is like a dictionary or a phone book where you look up a key to find its value quickly. It is simple and very fast for retrieving data by key.

intermediate

What is unique about Column NoSQL databases?

Column NoSQL databases store data in columns instead of rows. This means they group data by columns, which is efficient for reading and analyzing large amounts of similar data. It is like organizing a spreadsheet by columns to quickly find all values in one category.

beginner

What is a Graph NoSQL database used for?

A Graph NoSQL database stores data as nodes (things) and edges (relationships). It is great for showing connections, like social networks or maps. Imagine a web where dots are people and lines show their friendships.

intermediate

Which NoSQL database type is best for flexible, schema-less data?

Document databases are best for flexible, schema-less data because each document can have different fields and structures. This allows easy changes without redesigning the database.

Which NoSQL database type stores data as key-value pairs?

A Document

B Key-Value

C Column

D Graph

Key-Value databases store data as pairs of keys and values for fast lookup.

Which NoSQL type is best for representing relationships between data?

A Key-Value

B Column

C Graph

D Document

Graph databases store nodes and edges to represent relationships clearly.

What format do Document databases usually use to store data?

A JSON or BSON

B CSV

C XML

D Plain text

Document databases commonly use JSON or BSON formats for flexible documents.

Which NoSQL type organizes data by columns for efficient analytics?

A Column

B Document

C Graph

D Key-Value

Column databases store data in columns, making it fast to read similar data.

Which NoSQL type is simplest for quick data retrieval by a unique key?

A Graph

B Column

C Document

D Key-Value

Key-Value databases are simple and fast for retrieving data by unique keys.

Explain the four main types of NoSQL databases and give a simple example of when to use each.

Think about how data is stored and what real-life problem it solves.

Describe how a Graph NoSQL database differs from a Document NoSQL database.

Focus on data structure and use cases.