DynamoDB

Question 1

It is a low-latency NoSQL database.

Answer 1

Amazon DynamoDB

Question 2

What data models is supported by DynamoDB?

Answer 2

Supports both document and key-value data models.

Question 3

What document formats is supported by DynamoDB?

Answer 3

Supported document formats are JSON, HTML, XML

Question 4

What are the DynamoDB 2 types of Primary Keys?

Answer 4

Partition Key and Composite Key (combination of Partition Key + Sort Key)

Question 5

What are the DynamoDB features?

Answer 5

DynamoDB features consists of Tables, Items, and Attributes

Question 6

What are the DynamoDB 2 Consistency models?

Answer 6

Strongly Consistent and Eventually Consistent

Question 7

It allow users to access only the items where the partition key value matches their user ID.

Answer 7

Fine grained access control using IAM Condition parameter: dynamodb:LeadingKeys

Question 7

How access is controlled in a DynamoDB?

Answer 7

Access is controlled using IAM policies

Question 8

It enable fast queries on specific data columns?

Answer 8

DynamoDB Indexes

Question 9

DynamoDB Indexes gives you a different view of your data based on?

Answer 9

Alternative partition/sort keys.

Question 10

What DynamoDB Indexes has same partition key and different sort key to your table and must be created when you create your table

Answer 10

Local Secondary Index

Question 11

What DynamoDB Indexes has different partition key and different sort key to your table and can be created any time.

Answer 11

Global Secondary Index

Question 12

It’s operation finds items in a table using only the Primary
Key attribute and you provide the Primary Key name and a distinct value to search for.

Answer 12

Query

Question 13

It’s operation examines every item in the table and, by default, returns all data attributes.

Answer 13

Scan

Question 14

Its reverses the order of query results.

Answer 14

Set ScanIndexForward Parameter to False

Question 15

Query results are always sorted in?

Answer 15

In ascending order by the sort key if there is one.

Question 16

Use the _____________ parameter to refine the results.

Answer 16

ProjectionExpression

Question 17

How to making scans more efficient?

Answer 17

Reduce the impact of a query or scan by setting a smaller page size, which uses fewer read operations and isolate scan operations to specific tables, and segregate them from your mission-critical traffic.

Question 18

Try _________ rather than the default sequential scan.

Answer 18

Parallel Scans

Question 19

A __________ is generally more efficient than a scan.

Answer 19

Query Operation

Question 20

Design __________ in a way that you can use the Query, Get, or BatchGetItem APIs.

Answer 20

Tables

Question 21

It is measured in Capacity Units

Answer 21

Provisioned Throughput

Question 22

Write Capacity Units

Answer 22

1 x 1 KB write per second

Question 23

Strongly Consistent Reads

Answer 23

1 x 4 KB read per second

Question 24

Eventually Consistent Reads

Answer 24

2 x 4 KB reads per second

Question 25

When to use On-Demand Capacity?

Answer 25

Unpredictable application traffic. Pay-per-use model.

Question 26

When to use Provisioned Capacity?

Answer 26

Read and write capacity requirements can be forecasted. Application traffic is consistent or increases gradually.

Question 27

DAX is Not suitable for?

Answer 27

Write-intensive applications or applications that require strongly consistent reads.

Question 28

If the item you are querying is in the cache, DAX will ?

Answer 28

DAX will return it.

Question 28

You point your API calls at the _________ instead of your table.

Answer 28

DAX cluster

Question 29

Provides in-memory caching for DynamoDB tables.

Answer 29

DAX

Question 30

Improves response times for eventually consistent reads only.

Answer 30

DAX

Question 31

Data is written to the cache and the backend store at the same time.

Answer 31

DAX Write Operations

Question 32

In-memory cache sits between your application and database

Answer 32

Elasticache

Question 33

What are the 2 different caching strategies?

Answer 33

Lazy loading and Write Through

Question 34

It is the caching strategies that only caches the data when it is requested.

Answer 34

Lazy Loading

Question 35

It defines an expiry time for your data. Once expired, an item is marked for deletion

Answer 35

Time to live ( TTL )

Question 36

Great for removing irrelevant data or old data that reduce the cost of your DynamoDB Table.

Answer 36

Time to live ( TTL )

Question 37

It is the caching strategies that writes data into the cache whenever there is a change to the database.

Answer 37

Write Through caching strategy

Question 38

Elasticache Node failures not fatal, just lots of cache misses

Answer 38

Lazy Loading caching strategy

Question 39

Cache miss penalty: Initial request, query database, writing to cache

Answer 39

Lazy Loading caching strategy

Question 40

Avoid stale data by implementing a TTL

Answer 40

Lazy Loading caching strategy

Question 41

Data is never stale

Answer 41

Write Through caching strategy

Question 42

Write penalty: Each write involves a write to the cache

Answer 42

Write Through caching strategy

Question 43

Elasticache node failure means that data is missing until added or updated in the database

Answer 43

Write Through caching strategy

Question 44

Wasted resources if most of the data is never used

Answer 44

Write Through caching strategy

Question 45

It is a time-ordered sequence of item-level modifications in your DynamoDB tables.

Answer 45

DynamoDB Streams

Question 46

DynamoDB Streams Data is stored for how long?

Answer 46

24 hours only

Question 46

DynamoDB Streams Can be used as an _____________ , so you can create applications that take actions based on events in your DynamoDB table.

Answer 46

event source for Lambda

Question 47

This error means the number of requests is too high.

Answer 47

ProvisionedThroughputExceeded

Question 47

It improves flow by retrying requests using progressively longer waits.

Answer 47

Exponential Backoff

Question 48

Exponential backoff is a feature of ______________ and applies to many services within AWS.

Answer 48

Every AWS SDK

Question 49

The CLI and API call command and that creates a new table.

Answer 49

create-table CreateTable

Question 50

The CLI and API call command and that adds a new item into a table or replaces an old item with a new one.

Answer 50

put-item PutItem

Question 51

The CLI and API call command and that returns a set of attributes for an item with the given primary key.

Answer 51

get-item GetItem

Question 52

The CLI and API call command and that allows you to edit the attributes of an existing item (e.g., add or delete attributes).

Answer 52

update-item UpdateItem

Question 53

The CLI and API call command and that modifies a table (e.g., modify the provisioned throughput settings of the table).

Answer 53

update-table UpdateTable

Question 54

The CLI and API call command and that returns a list of tables in your account.

Answer 54

list-tables ListTables

Question 55

The CLI and API call command and that returns information about the table (e.g., current status, creation date, primary key, and indexes).

Answer 55

describe-table DescribeTable

Question 56

The CLI and API call command and that reads every item in a table and returns all items and attributes. Use a filter expression to return fewer items.

Answer 56

scan Scan

Question 57

The CLI and API call command and that queries the table based on a partition key value that you provide.

Answer 57

query Query

Question 58

The CLI and API call command and that allows you to delete an item based on its primary key.

Answer 58

delete-item DeleteItem

Question 59

The CLI and API call command and that deletes a table, including all of its items.

Answer 59

delete-table DeleteTable