Databases

Question 1

RDS

Answer 1

Use for OLTP. SQL Server, MySQL, PostgreSQL, Oracle, Aurora, MariaDB

Question 2

DynamoDB

Answer 2

NoSQL

Question 3

Redshift

Answer 3

OLAP

Question 4

Elasticache

Answer 4

In-memory caching. Memcached and Redis

Question 5

Multi-AZ

Answer 5

Used for failover, data synchronously replicated

Question 6

Read Replica

Answer 6

Used for frequent reads, up to 5 read replicas

Question 7

Aurora scaling

Answer 7

2 copies of your data in minimum 3 AZs, so 6 copies of your data. Designed to handle the loss of up to 2 copies of data w/o affecting writes, 3 copies w/o affecting reads. Self healing. Aurora replicas and MySQL read replicas

Question 8

DynamoDB vs RDS

Answer 8

DynamoDB has push button scaling, so scale your database on the fly. RDS - need to use bigger instance or add read replica

Question 9

DynamoDB properties

Answer 9

stored on SSD storage, spread across 3 geographically distinct data centers, eventual consistent reads (default), strongly consistent reads

Question 10

Redshift configuration

Answer 10

Single node (160 Gb), Multi-Node

Question 11

Multi-Node

Answer 11

Leader node (manages client connections and receives queries)
Compute node (store data and perform queries and computations). Up to 128 compute nodes