Domain 2: Storage

Question 1

What are the two main categories of storage systems?

Answer 1

Operational and Analytical

OP: RDS, DynamoDB, ElastiCache, Neptune
AN: Redshift, S3

Question 2

Characteristics of Operational Data Stores

Answer 2

• Data stored in a row-based format
• Smaller compute size
• Low latency
• High throughput
• High concurrency
• High change velocity
• Usually a good fit for caching
• Mission-critical, HA, DR, data protection

Question 3

Characteristics of RDS

Answer 3

• Fast - Choose between two SSD-backed storage options for high performance OLTP storage
• Scales Vertically - RDS is bounded by instance and storage sizes
• Reliable and Durable - Offers multi-AZ, automated backups, snapshots, and failovers

Question 4

Characterstics of DynamoDB

Answer 4

• Fast - Single-digit millisecond latency at any scale
• Scales Horizontally - Useful for storing unbounded data, providing low cost and high performance regardless of size
• Reliable and Durable - Data is replicated across three fault-tolerant AZs with fine grained access control. Offers global tables for multi-region replication

Question 5

Characterstics of ElastiCache

Answer 5

• Extreme performance - In-memory data store and cache using optimized stack to deliver sub-millisecond response times
• Reliable and Durable - Redis offers multi-az storage with automatic failover

Question 6

Characteristics of Neptune

Answer 6

• Fast and Scalable - Store billions of relationships and query with milliseconds latency
• Scales Vertically - Bounded by instance size and storage
• Relaiable and Durable - Six replicas of your data across 3 AZ with full backup and restore

Question 7

Which services can query data from S3 directly?

Answer 7

Redshift Spectum and Athena can query data in S3 with high speed and low latency without moving it out of S3

Question 8

Characteristics of Redshift

Answer 8

• Fast - Columnar storage technology to improve I/O efficiency and parallelize queries. Data loads linearly. Redshift also provides fastest query results using higher cost storage
• Reliable and Durable - Replicates your data within your data warehouse cluster and continuously backs up your Data to Amazon S3, which has 11 9s of durability

Question 9

Characterisitcs of S3

Answer 9

• Fast - provides a fast reliable platform for querying structured and semi structured data. Redshift Spectrum and Amazon Athena are able to query data without moving it from S3 at high speed with low latency
• Reliable and Durable - Data is always replicated across 3 AZ in the same region, 11 9s durability. S3 also offers same-region and cross region replication for even greater durability