DynamoDB

Question 1

What is provisioned throughput in DynamoDB?

Answer 1

Your read / write capacity.

Question 2

Is data in DynamoDB strong consistent, or eventually consistent?

Answer 2

Eventually consistent. But very fast.

Question 3

DynamoDB automatically copies your data to … availability zones.

Answer 3

3

Question 4

DynamoDB can not be as complex as SQL queries. This is by design. Why?

Answer 4

To push logic away from the database layer and to the computer layer

Question 5

Can dates be stored in DynamoDB straight up?

Answer 5

Nope. Must be converted to a time stamp

Question 6

What are the maximum amount of indexes allowed on a DynamoDB table?

Answer 6

10

Question 7

What’s max item size in DynamoDB

Answer 7

400kb

Question 8

In DynamoDB what is a composite key?

Answer 8

When you specify a primary key and a sort key

Question 9

True or false. In Dynamo database the only way to look up data is by primary key?

Answer 9

True

Question 10

What are the default read/writes in DynamoDB

Answer 10

5

Question 11

Does DynamoDB allow for bursting above capacity?

Answer 11

Yes but it’s very limited, and no details are specified by AWS

Question 12

True or false. AWS use DynamoDB burst capacity for maintenance

Answer 12

True

Question 13

In DynamoDB what is an RCU

Answer 13

Read capacity unit

Question 14

In DynamoDB what is a WCU

Answer 14

Write capacity unit

Question 15

The size limit of one DynamoDB RCU is…

Answer 15

4kb

Question 16

You need to retrieve an item from DynamoDB which is 16kb in size. How many RCUs will this use?

Answer 16

4

1 RCU = 4kb

16kb/4kb =4

Question 17

Are RCU requests strongly or eventually consistent?

Answer 17

By default, strongly. But they can be set to eventually.

Question 18

What’s the benefit of an eventually consistent RCU

Answer 18

They cost half compared to a strongly consistent RCU

Question 19

Want to query DynamoDB. Your two options are…

Answer 19

Query

Scan

Question 20

Want to search a whole table across all partion keys? What to use?

Answer 20

A scan

Question 21

Want to search a specific table for a single portion key? What to use?

Answer 21

A query

Question 22

Can DynamoDB scans be strongly consistent?

Answer 22

No. Only eventually.

Question 23

Can DynamoDB scans be ran in parallel?

Answer 23

Yes

Question 24

Can DynamoDB scans be ordered?

Answer 24

No

Question 25

Generally speaking. Will a query or a scan use more RCU’s

Answer 25

Scan

Question 26

Can a DynamoDB query be ordered?

Answer 26

Yes. By sort key.

Question 27

Are DynamoDB queries strongly or eventually consisent?

Answer 27

Either. strongly by default

Question 28

What is the size limit of one WCU in DynamoDB

Answer 28

1kb

Question 29

In DynamoDB must you provision throughput for each secondary index?

Answer 29

Yes

Question 30

In DynamoDB database what is a GSI?

Answer 30

Global secondary index

Question 31

What is the GSI limit per table in DynamoDB

Answer 31

5

Question 32

In DynamoDB what is an LSI

Answer 32

Local secondary index

Question 33

What is the LSI limit per DynamoDB table?

Answer 33

5

Question 34

True or false. LSIs share throughput of the existing table in DynamoDB

Answer 34

True

Question 35

When creating a primary key in an index. You can choose what …… you project into the index.

Answer 35

Attributes

Question 36

Is partioning in DynamoDB automatic?

Answer 36

Yes

Question 37

What triggers partioning in DynamoDB

Answer 37

A table getting to 10gb in size. Or. High throughput.

Question 38

You want to know how many partitions your DynamoDB table has. How do you do this?

Answer 38

Contact AWS

Question 39

Can DynamoDB partitions be removed or reduced after creation?

Answer 39

No

Question 40

In DynamoDB partion keys are also sometimes known as

Answer 40

Hash keys

Question 41

Describe what happens when a partition is created in DynamoDB

Answer 41

Two new partitions are created. Data is copied to these new partions and the original partition is deleted.

Question 42

Do dynamo database read and writes slow as the table increases in size?

Answer 42

No