M8: Databases

Question 1

Amazon Relational database service

Answer 1

Database instance which can contain multiple user created databases
You manage your application optimization
AWS manages installing and patching OS, DB software, automatic backups and high availability. Scales resources, manages power and servers, performs maintenance.

Question 2

Multi AZ deployment of RDS

Answer 2

Automatically generates a standby copy of database in another AZ within same region
Synchronously replicates to standby copy

Question 3

When to use RDS

Answer 3

Good for Web and mobile applications that need a DB with high throughput, massive storage scalability and high availability
When need complex transactions or complex queries
Medium to high query rate
No more than a single worker node or shard
High durability

Question 4

When not to use RDS

Answer 4

If application requires
Massive read / write rates
Sharding due to high data size or throughput demands
Simple GET or PUT requests and queries that a NoSQL DB can handle
Or needs relational DB management system customization

Question 5

RDS pricing

Answer 5

Consider clock hours of service time
Database characteristics
Capacity of database
Database engine
Number of databases instances
Database purchase type
Provisioned storage
Data transfer

Question 6

Amazon DynamoDB

Answer 6

Fast and flexible NoSQL database service for all applications that need consistent, single digit latency at any scale
Partitions data and has table storage
Stored on solid state drives
Replicate across AWS regions, encryption at rest, set item time to live

Question 7

Core DynamoDB components

Answer 7

Tables: collections of data
Items: groups of attributes
Attributes: fundamental data element

Question 8

DynamoDB primary keys types

Answer 8

Partition key

Sort key

Question 9

DynamoDB use cases

Answer 9

Good for mobile, Web, gaming, as tech and iot applications

Question 10

Amazon Redshift

Answer 10

Fast, fully managed data warehouse
Can use standard SQL
Designed to consistently deliver high performance
Uses columnar storage and massively parallel processing architecture
Automatically backs up data, can be encrypted

Question 11

Amazon Redshift working

Answer 11

Leader node manages communications with client programs and compute nodes
Plans
Compiles code for individual elements of the execution plan and assigns the code to individual compute nodes
Can run queries against exabytes of data directly in S3

Question 12

Amazon Aurora

Answer 12

MySQL and PostgreSQL compatible relational database
Fully managed
Highly available: multiple copies in AZs and continuous backups
Reduces restart time after crash to less than 60 seconds
Straighforward to set up
Fast, distributed storage subsystem

Question 13

Retrieving data from DynamoDB

Answer 13

Query operation: uses partitioning to effectively locate items using the primary key
Scan: locate items in table by matching conditions on non key attributes