Databases on AWS

Question 1

What is RDS?

Answer 1

AWS’s relational database service.

Question 2

What is RDS primarily used for?

Answer 2

OLTP- Online Transaction Processing

Question 3

What is DynamoDB primarily used for?

Answer 3

OLAP- Online Analytics Processing

Question 4

What are the 6 engines currently supported on RDS?

Answer 4

1) mySQL
2) Amazon Aurora
3) PostgreSQL
4) MariaDB
5) Oracle
6) SQL server

Question 5

What is Redshift?

Answer 5

AWS’s data warehousing solution.

Question 6

What is ElastiCache?

Answer 6

Service used to cache frequently used queries to improve performance of existing databases:

Question 7

Name 2 ElastiCache engines?

Answer 7

1) Redis- Advanced multi AZ or backups

2) Memcached- Basic caching

Question 8

What does RDS run on?

Answer 8

VMs

Question 9

Can you access a RDS?

Answer 9

No, you cannot SSH into a RDS vm

Question 10

Who is responsible for patching RDS OSs?

Answer 10

AWS is responsible for patching underlying VM of an RDS instance

Question 11

Is RDS serverless?

Answer 11

No, but Amazon’s Aurora is serverless

Question 12

Is DynamoDB serverless?

Answer 12

Yes

Question 13

What are the 2 types of backups available on RDS?

Answer 13

1) Automated backups

2) Database snapshots

Question 14

What is a read replica and why would you use one?

Answer 14

Read replica is the process of replicated an RDS instance and using one copy for read only and the primary RDS instance as the read/write instance. It is used to improve the performance of a database.

Question 15

Can read replicas be multi AZ?

Answer 15

Yes

Question 16

What must be turned on to activate read replicas?

Answer 16

Backups must be turned on to use read replicas

Question 17

Which 5 database engines can use read replicas?

Answer 17

1) MySQL
2) PostreSQL
3) MariaDB
4) Oracle
5) Aurora

Question 18

What is RDS multi AZ used for?

Answer 18

Disaster recovery

Question 19

Can Encryption be used for an RDS?

Answer 19

Yes, this can be done using the AWS key management service

Question 20

What are the 2 key features of RDS?

Answer 20

1) Stored on SSD storage

2) Spread across 3 geographically distinct data centers

Question 21

What is the default back up duration for redshift?

Answer 21

1 day, but can be changed to 35 days

Question 22

By default how many copies does AWS keep of your Redshift data?

Answer 22

3 –> Original, replica on compute node and a back up on S3 (DR)

Question 23

How many copies of you data does Aurora keep by default?

Answer 23

Aurora automatically maintains 6 copies of your data across 3 Availability Zones and will automatically attempt to recover your database in a healthy AZ with no data loss

Question 24

Can you share Aurora snapshots with other AWS accounts?

Answer 24

Yes

Question 25

Does aurora have auto-back up switched on by default?

Answer 25

Yes

Question 26

How many AZ is data spread over by default with DynamoDB

Answer 26

1

Question 27

What are the 3 data formats supported by Athena?

Answer 27

1) Apache Paraquet
2) JSON
3) Apache ORC

Question 28

How would you run a database from an EC2 instance?

Answer 28

Create EC2 instance and use EBS for storage of the database