NoSQL DB Terminology

Question 1

What is a NoSQL Database

Answer 1

non relational database designed to handle large volumes of unstructured, semi-structured, or structured data with high scalability and flexibility.

data models: Support diverse data models like key-value, document, graph, distributed architecture, and performance

use-case - for big data, real-time analytics, modern applications

Question 2

What are some examples of NOSQL Databases

Answer 2

MongoDB, Cassandra, Redis

Amazon DynamoDB
Azure Cosmos DB
Google Cloud Firestore

Question 3

What is High Availability

Answer 3

HA means the db stays up and running with minimal downtime.

It does this through replica sets to automatically switch to a backup node if the primary fails.

This ensures the data is always accessible.

HA is achieved through distributed architecture, replication, automatic failover, eventual consistency.

Question 4

What is Distributed Architecture

Answer 4

data is replicated across multiple nodes or servers, often in different geographic regions, ensuring that if one node fails, others can take over

Question 5

What is Replication

Answer 5

multiple copies of data are maintained (e.g. leader-follower or peer to peer replication), allowing failover to a replica if the primary node goes down

Question 6

What is Automatic Failover

Answer 6

system detects failures and reroutes requests to healthy nodes without manual intervention

Question 7

What is ‘Eventual Consistency’

Answer 7

Many noSQL db’s prioritize availability over immediate consistency, ensuring data remains accessible even if updates are temporarily inconsistent across nodes

Question 8

What is Federation?

Answer 8

Splitting a NoSQL db into smaller, independent databases (or shards) based on logical or functional boundaries, where each federated db handles a specific subset of the application’s data or workload.

Question 9

What is Sharding

Answer 9

partitioning a single NoSQL db across multiple nodes or servers, where each shard holds a subset of the data based on a shard key (e.g. user ID).

Question 10

Federation vs Sharding

Answer 10

both enhance scalability and performance in NoSQL systems, but address different needs:

Federation organizes data by function or domain

Sharding distributes a single dataset for parallel processing.

Question 11

What is Fault Tolerance

Answer 11

db’s ability to continue operating reliably and maintain data availability in the event of a hardware failure, network issue, or other disruption.

MongoDB achieves fault tolerance through its replica sets.