Databases

Question 1

Amazon Neptune

Answer 1

• Fully managed graph database
• A popular graph dataset would be a social network
• Users have friends
• Posts have comments
• Comments have likes from users
• Users share and like posts…
• Highly available across 3 AZ, with up to 15 read replicas
• Build and run applications working with highly connected
  datasets – optimized for these complex and hard queries
• Can store up to billions of relations and query the graph with
  milliseconds latency
• Highly available with replications across multiple AZs
• Great for knowledge graphs (Wikipedia), fraud detection,
  recommendation engines, social networking

Question 2

DocumentDB

Answer 2

• Aurora is an “AWS-implementation” of PostgreSQL / MySQL …
• DocumentDB is the same for MongoDB (which is a NoSQL database)
• MongoDB is used to store, query, and index JSON data
• Similar “deployment concepts” as Aurora
• Fully Managed, highly available with replication across 3 AZ
• DocumentDB storage automatically grows in increments of 10GB, up to 64 TB.
• Automatically scales to workloads with millions of requests per seconds

Question 3

Amazon QuickSight

Answer 3

• Serverless machine learning-powered business intelligence service to
  create interactive dashboards
• Fast, automatically scalable, embeddable, with per-session pricing
• Use cases:
• Business analytics
• Building visualizations
• Perform ad-hoc analysis
• Get business insights using data
• Integrated with RDS, Aurora, Athena, Redshift, S3…

Question 4

Amazon Athena

Answer 4

Serverless query service to analyze data stored in Amazon S3
* Uses standard SQL language to query the files
* Supports CSV, JSON, ORC, Avro, and Parquet (built on Presto)
* Pricing: $5.00 per TB of data scanned
* Use compressed or columnar data for cost-savings (less scan)
* Use cases: Business intelligence / analytics / reporting, analyze &
query VPC Flow Logs, ELB Logs, CloudTrail trails, etc…
* Exam Tip: analyze data in S3 using serverless SQL, use Athena

Question 5

Amazon EMR
(Elastic MapReduce)

Answer 5

• 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
• Also supports Apache Spark, HBase, Presto, Flink…
• EMR takes care of all the provisioning and configuration
• Auto-scaling and integrated with Spot instances
• Use cases: data processing, machine learning, web indexing, big data…

Question 6

Redshift

Answer 6

• Redshift is based on PostgreSQL, but it’s not used for OLTP
• It’s 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)
• Massively Parallel Query Execution (MPP), highly available
• Pay as you go based on the instances provisioned
• Has a SQL interface for performing the queries
• BI tools such as AWS Quicksight or Tableau integrate with it

Question 7

DynamoDB

Answer 7

• Fully Managed Highly available with replication across 3 AZ
• NoSQL database - not a relational database
• Scales to massive workloads, distributed “serverless” database
• Millions of requests per seconds, trillions of row, 100s of TB of storage
• Fast and consistent in performance
• Single-digit millisecond latency – low latency retrieval
• Integrated with IAM for security, authorization and administration
• Low cost and auto scaling capabilities
• Standard & Infrequent Access (IA) Table Class

DynamoDB Accelerator - DAX
* Fully Managed in-memory cache for DynamoDB
* 10x performance improvement – single- digit millisecond latency to microseconds latency – when accessing your DynamoDB tables
* Secure, highly scalable & highly available
* Difference with ElastiCache at the CCP level: DAX is only used for and is integrated with DynamoDB, while ElastiCache can be used for other databases applications table Amazon

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

Question 8

Amazon Aurora

Answer 8

• Aurora is a proprietary technology from AWS (not open sourced)
• OLTP database
• PostgreSQL and MySQL are both supported as Aurora DB
• Aurora is “AWS cloud optimized” and claims 5x performance improvement over MySQL on RDS, over 3x the performance of Postgres on RDS
• Aurora storage automatically grows in increments of 10GB, up to 128 TB
• Aurora costs more than RDS (20% more) – but is more efficient
• Not in the free tier

Question 9

Amazon QLDB

Answer 9

• QLDB stands for ”Quantum Ledger Database”
• 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 system: no entry can be removed or modified, cryptographically verifiable
• 2-3x better performance than common ledger blockchain frameworks, manipulate data using SQL
• Difference with Amazon Managed Blockchain: no decentralization component, in accordance with financial regulation rules

Question 10

Amazon Managed Blockchain

Answer 10

• Blockchain makes it possible to build applications where multiple parties can execute transactions without the need for a trusted, central authority.
• Amazon Managed Blockchain is a managed service to:
  Join public blockchain networks
  Or create your own scalable private network
• Compatible with the frameworks Hyperledger Fabric & Ethereum

Question 11

AWS Glue

Answer 11

• Managed extract, transform, and load (ETL) service
• Useful to prepare and transform data for analytics
• Fully serverless service
• Glue Data Catalog: catalog of datasets
• Can be used by Athena, Redshift, EMR

Question 12

DMS – Database Migration Service

Answer 12

• Quickly and securely migrate databases to AWS, resilient, self healing
• The source database remains available during the migration

Supports:
* Homogeneous migrations: ex Oracle to Oracle
* Heterogeneous migrations: ex Microsoft SQL Server to Aurora