DynamoDB

Question 1

What is DynamoDB

Answer 1

A managed, multi-A, NoSQL data store with cross-region replication option

Question 2

Since DynamoDB is multi-AZ, what consistency model does it follow?

Answer 2

eventual consistency by default. Strong consistency can be programmed via SDK

Question 3

Generally speaking, what is pricing for DynamoDB based on?

Answer 3

throughput

Question 4

What options do you have if you anticipate overwhelming demand?

Answer 4

You can provision read and write capacity

Question 5

What is DynamoDB autoscale based on?

Answer 5

configured min/max levels.

Question 6

What is the downside to DynamoDB autoscale?

Answer 6

It does not scale back down after it has scaled up. You have to intervene.

Question 7

What is the alternative to autoscale?

Answer 7

on-demand capacity. Comes with premium pricing.

Question 8

How can ACID compliance be met with DynamoDB?

Answer 8

Using DynamoCB Transactions. Configurable in the SDK

Question 9

What is a name/value pair known as?

Answer 9

Attribute

Question 10

What is the whole collection of names and values referred to as?

Answer 10

Item

Question 11

What are multiple items known as?

Answer 11

Table

Question 12

What must every record (or item?) have to identify it?

Answer 12

a primary key

Question 13

Must a primary key be unique?

Answer 13

yes

Question 14

to access an item, or record I dynamoDB, what information do you need?

Answer 14

just the Name of the name-value pair what comprises the primary key

Question 15

What is a global secondary index?

Answer 15

Partition key and sort key can be different from those on the table

Question 16

What is the local secondary index

Answer 16

Same partition key as the table but different sort key.

Question 17

When would you use a global secondary key?

Answer 17

for fast queries of attributes outside of the primary key without scanning the whole table.

Question 18

when would you use local secondary index?

Answer 18

When you already know the partition key and want to quickly query on some other attribute

Question 19

What should you do when your most common DynamoDB queries do not use the partition key?

Answer 19

Create a Global Secondary Index with the most common queried attribute as the hash key.
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.CoreComponents.html

Question 20

What DynamoDB features can be utilized to increase the speed of read operations?

Answer 20

DynamoDB Accelerator (DAX)
Secondary Indexes
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/SecondaryIndexes.html