Databases

Question 1

What are disks vs. databases?

Answer 1

Disks: EFS, EBS, EC2 Instance Store, S3

Databases: RDS, Aurora, ElastiCache, DynamoDB, Redshift, EMR, Athena, QuickSight, DocumentDB, Neptune, QLDB, Managed Blockchain, DMS, Glue

Question 2

What does a database let you do that a disk can’t?

Answer 2

Structure data, build indices to efficiently query/search data, and define relationships b/w your datasets

Question 3

Benefits of no-SQL databases? What form do they take?

Answer 3

Flexible, scalable, high-performance, and high-functional

JSON

Question 4

What is the benefit of using AWS databases?

Answer 4

AWS manages them:

• Quick Provisioning, High Availability, Vertical and Horizontal Scaling
• Automated Backup & Restore, Operations, Upgrades
• Operating System Patching is handled by AWS
• Monitoring, alerting

Question 5

What are relational databases?

Answer 5

RDS & Aurora (SQL)

Question 6

In-memory Database

Answer 6

ElastiCache

Question 7

Key/Value Database? Can it be used serverless? What’s its caching mechanism?

Answer 7

DynamoDB (serverless)

DAX (cache for DynamoDB)

Question 8

Data warehouse

Answer 8

Redshift (SQL)

Question 9

Hadoop Cluster

Answer 9

EMR

Question 10

How can you query data on Amazon S3?

What can it handle? (options below)
servers
severless
sql 
no-sql

Answer 10

Athena

Serverless and can handle SQL

Question 11

What is a managed Hyperledger Fabric & Ethereum blockchains?

Answer 11

Amazon Managed Blockchain

Question 12

Managed ETL (Extract Transform Load) and Data Catalog service

Answer 12

Glue

Question 13

DMS & traits?

Answer 13

Database migration system - allows intervals, quickly and securely migrates DB to AWS in a resilient and self healing, while allowing source database to remain available during the migration

Question 14

Graph database

Answer 14

Neptune

Question 15

dashboards on your data (serverless)

Answer 15

QuickSight

Question 16

“Aurora for MongoDB” (JSON – NoSQL database)

Answer 16

DocumentDB

Question 17

What allows you to create databases managed by AWS for the following:
• Postgres
• MySQL
• MariaDB
• Oracle
• Microsoft SQL Server
• Aurora (AWS Proprietary database)

Answer 17

RDS

Question 18

What are the pros & cons to RDS vs. DB on EC2?

Answer 18

RDS is a managed service:
• Automated provisioning, OS patching
• Continuous backups and restore to specific timestamp (Point in Time Restore)!
• Monitoring dashboards
• Read replicas for improved read performance
• Multi AZ setup for DR (Disaster Recovery)
• Maintenance windows for upgrades
• Scaling capability (vertical and horizontal)
• Storage backed by EBS (gp2 or io1)
• BUT you can’t SSH into your instances

Question 19

What are supported by Aurora DB (which is cloud-optimized)?

Answer 19

PostgreSQL and MySQL

Question 20

What are 3 unique features of RDS deployments?

Answer 20

1. Can read replicas to scale the read workload of your DB (1 app can read from 3 Amazon RDS - 1 main/2 replicas)
2. Can do multi-AZ and failover in case of AZ outage (high availability); read/write to main RDS but rep across AZ to 1 other RDS
3. Can do multi-region; if disaster in 1 region, can do local performance for global reads, ensure disaster recovery in case of region issues, but charge rep cost

Question 21

What do you use ElastiCache for?

Answer 21

To get managed Redis or Memcached; caches are in-memory DB and allows reducing load of DB for read-intensive wkloads; allows quicker read/write from cache

Question 22

What is a noSQL DB that can scale to massive workloads due to its distributed serverless DB with single-digit milisecond latency?

Answer 22

DynamoDB

Question 23

What is a fully managed in-memory cache for DynamoDB that improves performance by 10X?

Answer 23

DAX

Question 24

What is a postgreSQL based OLAP that has columnar storage of data?

Answer 24

Redshift

Question 25

What helps create Hadoop clusters (Big Data) to analyze and process vast amount of data, where clusters could be hundreds of EC2 instances; and is used for data processing, machine learning, web indexing, and big data?

Answer 25

Elastic MapReduce

Question 26

What is a fully Serverless database with SQL capabilities?

Answer 26

Athena

Question 27

What are the use cases of Athena?

Answer 27

one-time SQL queries, serverless queries on S3, log analytics

Question 28

What is the relationship between S3 and Athena?

Answer 28

Query data in S3 and get output to S3

Question 29

What is the pricing of Athena?

Answer 29

Pay per query

Question 30

What is a serverless machine learning-powered business intelligence service to create interactive dashboards?

Answer 30

Amazon QuickSight

Question 31

What is AWS version of a NoSQL database for storing, querying, and indexing JSON data?

Answer 31

DocumentDB

Question 32

What is a fully managed graph database (e.g. social network) that is highly available (3 AZ) and up to 15 read replicas?

Answer 32

Amazon Neptune

Question 33

What can be used to review history of all the changes made to your application data over time, and is immutable?

Answer 33

Quantum ledger database

Question 34

How is QLDB different from Amazon Managed Blockchain?

Answer 34

No decentralization component, in accordance with | financial regulation rules

Question 35

What is a serverless AWS svc used to manage extract, transform, and load (ETL), i.e. useful for preparing and transforming data for analytics?

Answer 35

AWS Glue

Question 36

What can Glue Data Catalogue be used by?

Answer 36

Athena, Redshift, EMR (Elastic MadReduce)

Question 37

What svc can be used for quickly and securely migrating databases to AWS, resilient, self healing?

Answer 37

Database Migration Svc (DMS)