Read replicas in GCP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a read replica in cloud databases?

A read replica is a copy of a database that handles read-only queries. It helps reduce the load on the main database by serving read requests separately.

beginner

Why use read replicas in Google Cloud SQL?

Read replicas improve performance by distributing read traffic, increase availability, and help with backup and reporting without affecting the main database.

intermediate

How does data stay updated in a read replica?

Data is copied asynchronously from the main database to the read replica, meaning there might be a small delay before changes appear in the replica.

beginner

Can you write data directly to a read replica?

No, read replicas are read-only. All write operations must go to the main database to keep data consistent.

intermediate

What happens if the main database fails when using read replicas?

Read replicas can be promoted to become the new main database, helping to restore service quickly.

What is the main purpose of a read replica?

A To handle read-only queries and reduce load on the main database

B To store backups of the database

C To process write operations faster

D To replace the main database permanently

Read replicas serve read-only queries to reduce the load on the main database.

How is data copied from the main database to a read replica?

A Asynchronously with possible delay

B Synchronously with no delay

C Manually by the user

D Only during backups

Data replication to read replicas is asynchronous, so there can be a small delay.

Can you write data directly to a read replica in Google Cloud SQL?

A Yes, anytime

B Only during maintenance

C No, read replicas are read-only

D Only if promoted to main

Read replicas do not accept write operations; writes must go to the main database.

What benefit do read replicas provide during high traffic?

A They increase write speed

B They distribute read traffic to improve performance

C They reduce storage costs

D They automatically delete old data

Read replicas help by distributing read traffic, improving performance under load.

What can happen if the main database fails when using read replicas?

A Read replicas become read-write automatically

B The system stops working immediately

C Data is lost permanently

D Read replicas can be promoted to main to restore service

Read replicas can be promoted to become the new main database to restore service quickly.

Explain what a read replica is and why it is useful in cloud databases.

Think about how copying data helps with many users reading at the same time.

Describe how data replication works between a main database and its read replicas.

Consider how changes travel from the main to the copies.