Databases Section

Question 1

Relational Database

Answer 1

• Looks just like Excel spreadsheets, with links

* Can use the SQL language to perform queries / lookups

Question 2

AWS RDS

Answer 2

• It’s a managed DB service for DB use SQL as a query language.
• It allows you to create databases in the cloud that are managed by AWS

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 3

Amazon Aurora

Answer 3

• Aurora is a proprietary technology from AWS (not open sourced)
• PostgreSQL and MySQL are both supported as Aurora DB
• Aurora is “AWS cloud optimized” and claims 5x performance improvement
over MySQL on RDS

Question 4

RDS Deployment, Read Replicas

Answer 4

• Scale the read workload of your DB
• Can create up to 5 Read Replicas
• Data is only written to the main DB

Question 5

RDS Deployment, Multi AZ

Answer 5

• Failover in case of AZ outage (high availability)
• Data is only read/written to the main database
• Can only have 1 other AZ as failover

Question 6

RDS Deployment, Multi-Region (Read Replicas)

Answer 6

• Disaster recovery in case of region issue
• other AZs read from their DB but write on the main DB
• Local performance for global reads
• Replication cost

Question 7

Amazon Elasticache

Answer 7

• ElastiCache is to get managed Redis or Memcached
• Caches are in-memory databases with high performance, low latency
• Helps reduce load off databases for read intensive workloads
• AWS takes care of OS maintenance / patching, optimizations, setup,
configuration, monitoring, failure recovery and backups

Question 8

Dynamo DB

Answer 8

• Fully Managed Highly available with replication across 3 AZ
• NoSQL, serverless
• Single-digit millisecond latency – low latency retrieval
• Integrated with IAM for security, authorization and administration
• Low cost and auto scaling capabilities
• Key/value database

Question 9

DynamoDB Accelerator - DAX

Answer 9

• Fully Managed in-memory cache for ONLY DynamoDB

* 10x performance improvement

Question 10

DynamoDB Global Tables

Answer 10

• Make a DynamoDB table accessible with low latency in multiple-regions
• Active-Active replication (read/write to any AWS Region)

Question 11

Redshift Overview

Answer 11

• PostGre SQL OLAP – online analytical processing (analytics and data warehousing)
• Load data once every hour, not every second
• 10x better performance than other data warehouses, scale to PBs of data
• Columnar storage of data (instead of row based)
• pay as you go

Question 12

Amazon EMR

Answer 12

• EMR stands for “Elastic MapReduce”
• EMR helps creating Hadoop clusters (Big Data) to analyze and process vast amount of data
• The clusters can be made of hundreds of EC2 instances
• EMR takes care of all the provisioning and configuration

Question 13

Amazon Athena

Answer 13

• Serverless query service to analyze data stored in Amazon S3
• Uses standard SQL language to query the files

Question 14

Amazon QuickSight

Answer 14

• Serverless machine learning-powered business intelligence service to create interactive dashboards
• Integrated with RDS, Aurora,Athena, Redshift, S3

Question 15

DocumentDB

Answer 15

• Aurora is an “AWS-implementation” of PostgreSQL / MySQL …

* DocumentDB is the same for MongoDB (which is a NoSQL database)

Question 16

Amazon Neptune

Answer 16

• Fully managed graph database
• A popular graph dataset would be a social network
• Highly available across 3 AZ, with up to 15 read replicas
• Great for knowledge graphs (Wikipedia), fraud detection, recommendation engines, social networking

Question 17

Amazon QLDB

Answer 17

• A ledger is a book recording financial transactions
• Fully Managed, Serverless, High available, Replication across 3 AZ
• Used to review history of all the changes made to your application data over time
• Immutable and centralized

Question 18

Amazon Managed Blockchain

Answer 18

• decentralized way to build applications where multiple parties can execute transactions
• Compatible with the frameworks Hyperledger Fabric & Ethereum

Question 19

AWS Glue

Answer 19

• Managed extract, transform, and load (ETL) service
• Useful to prepare and transform data for analytics
• Fully serverless service