M13 : Dynamo DB

By default, DynamoDB is resilient on a __ basis. (Choose two answers)

• national

• Cross AZ

• global

• regional

You have an application with several hundred IoT devices all sending data into S3. Your team has created a mobile application that relies on reading data from DynamoDB. How could you give each mobile device permissions to read that data from DynamoDB?

• Create an IAM user.

• Add an encrypted username and password into the app code and decrypt it at runtime.

• Connect to an EC2 instance which will pull the data from DynamoDB securely.

• Create an IAM role that can be assumed by an app that allows federated users.

Which is true of DynamoDB Streams? (Choose all that apply)

• There are four Stream views.

• When a Stream is enabled, it holds changes to the entire database.

• DynamoDB and its Stream are highly resilient.

• Streams hold a rolling 48-hour window of changes to a table.

• Streams can be used to invoke Lambda functions.

In DynamoDB, what does the primary key contain? (Choose all that apply)

• a partition key

• Only a sort key

• A hash key and a range key

• A partition key and a sort key

Which service is used specifically for in-memory caching within DynamoDB?

• DAX

• CloudFront

• Memcached

• Redis​

A startup company is developing a web application with DynamoDB as database with a provisioned throughput of 1000 ​

Writes/sec. They are expecting high number of writes on the DB during peak hours expecting ~3000 writes/sec. How could you ensure the scalability and cost effectiveness to reduce the load on DynamoDB ?​

​

(Choose all that apply)

• Add more DynamoDB databases to handle load.

• Use DynamoDB autoscaling.

• Increase write capacity of DynamoDB to meet peak loads.

• Use SQS to assist and let the application pull messages and then perform relevant operation in DynamoDB.

• Use Kinesis to assist and let the application pull messages and then perform relevant operation in DynamoDB.

In DynamoDB, what is the difference between a scan and a query operation?

• There is no difference between scan and query because they both search through a table.

• All of these answers are incorrect.

• A scan will search the whole table, which uses more computing power. A query operation searches for only the primary key attributes, that are more efficient.

• A scan will search only primary key attributes, which is more efficient. A query will search the whole table, which uses more computing power.

Which situations would call for the use of DynamoDB? (Choose two answers)

• When you need to perform complex queries with joins across tables.

• When you need a database for relational of SQL based data.

• When needing a web-scalable DBaaS product that provides integration with CloudWatch.

• When needing a database with a fixed schema.

• When needing a lightweight, on-demand database product

In DynamoDB, what does the primary key contain? (Choose all that apply)

• A partition key

• Only a sort key

• A hash key and a range key

• A partition key and a sort key

Which DynamoDB backup method saves the table settings and the data within a table while creating a new table?​

(Choose two answers)

• point-in-time backups

• Default customer managed keys

• KMS

• On-demand backup