Databases

Question 1

What databases are available on RDS?

Answer 1

MySQL, SQL Server, PostgreSQL, Oracle, Aurora, MariaDB

Question 2

Which database service would you choose for OLTP?

Answer 2

RDS

Question 3

Which database service would you choose for OLAP?

Answer 3

Redshift

Question 4

What caching services does Elasticache use?

Answer 4

Redis and Memcached

Question 5

What can you provision for higher performance in RDS?

Answer 5

RDS Read Replicas to scale reads

Question 6

What disaster recover solution is available for RDS?

Answer 6

Multi-AZ RDS deployments are perfect for DR; you can manually trigger a failover, too

Question 7

What two types of backups are available for RDS?

Answer 7

Automatic (which are enabled by default and are stored for free in S3) and Snapshots, which are manual and incremental and ar stored even after you delete your RDS

Question 8

What is the default retention period for RDS backups?

Answer 8

35 days

Question 9

How many availability zones is DynamoDB available in by default?

Answer 9

3 AZs

Question 10

What is the default read model for DynamoDB?

Answer 10

Eventual Consistent reads, which consistency is reached by 1 second

Question 11

What kind of consistency can be enabled to reach consistency in less than 1 second?

Answer 11

Strongly consistent reads

Question 12

How many tables can you have per AWS Account for DynamoDB?

Answer 12

256/region

Question 13

What is the maximum item size in DynamoDB

Answer 13

400KB

Question 14

What is the maximum item size in DynamoDB

Answer 14

400KB

Question 15

What are the primary cost components of DynamoDB

Answer 15

Pay for reads and writes by the mullion request units and for data storage above 25GB/month

Question 16

True or False: you pay for DynamoDB Data transfer to AWS services within the same region?

Answer 16

False

Question 17

How many copies of your data does Aurora store by default?

Answer 17

6: 2 copies in 3 availability zones

Question 18

True or False: You can share RDS Aurora snapshots across AWS accounts?

Answer 18

True

Question 19

How many availability zones can you have with Redshift?

Answer 19

Only available in 1 AZ

Question 20

What is the max retention for Redshift backups?

Answer 20

35 days

Question 21

How many copies of data will Redshift attempt to maintain?

Answer 21

3: the original, one is S3 and the replica

Question 22

What scale of data can Redshift handle?

Answer 22

Up to Petabytes

Question 23

What advantages does Redshift have over traditional data warehouse technologies

Answer 23

Columnar data storage, advanced compression, no need for indices, scalability, massively parallel processing, and Redshift Spectrum for unstructured data in S3

Question 24

Which service can you use to sync your on-premise database to an AWS database?

Answer 24

AWS Database Migration Service, which can perform homogenous and heterogenous migrations (and not just to databases, but also to S3, Elasticsearch, Kinesis, DynamoDB, DocumentDB and EC2)