Knowledge Check: Databases (CLF-C01)

Question 1

What database is a Key-Value store?

A. Amazon Redshift
B. Amazon RDS
C. Amazon QLDB
D. DynamoDB

Answer 1

D. DynamoDB

Explanation:
The AWS managed NoSQL database that is a Key-Value store is DynamoDB. Key-Value stores are designed for storing, retrieving, and managing associative arrays and are well suited for working with large amounts of data.

Question 2

Which relational database service is an iteration of MySQL and only available on AWS?

A. MariaDB

B. Postgres

C. Aurora

D. Redshift

Answer 2

B. Postgres

Explanation:
Amazon Aurora is an iteration of MySQL and offers faster processing. It is a cloud-native database service only available on AWS.

Question 3

What does Amazon RDS perform?
A. It offers a managed relational database service.
B. It offers a cloud service that can host user-managed relational databases.
C. It offers a managed data warehouse service.
D. It offers a managed non-relational database service.

Answer 3

A. It offers a managed relational database service.

Explanation:
Amazon RDS manages the work involved in setting up a relational database: from provisioning the infrastructure capacity you request to installing the database software. The other choices briefly summarize Amazon EC2, Amazon Redshift, and Amazon DynamoDB.

Question 4

In Amazon RDS, what is the purpose of Multi-AZ deployment?
A. to create high availability and data redundancy
B. to create a database with highly configurable options
C. to prevent users from outside your VPC security group from accessing your database
D. to enable automatic backups

Answer 4

A. to create high availability and data redundancy

Explanation:
If high availability and resiliency are of importance when it comes to your database, then you might want to consider a feature known as Multi-AZ, which stands for multi-availability zones. When Multi-AZ is configured, a secondary RDS instance is deployed within a different availability zone within the same region as the primary instance. The primary purpose of the second instance is to provide a failover option for your primary RDS instance. When we have a Multi-AZ deployment, it will create another standby instance in a different availability zone to create high availability and data redundancy.

Question 5

Amazon ElastiCache allows you to retrieve information from _____.

A. different web servers in the cloud
B. NoSQL databases
C. relational databases
D. in-memory data stores

Answer 5

D. in-memory data stores

Explanation:
Amazon ElastiCache is a service that makes it easy to deploy, operate, and scale open-source, in-memory data stores in the cloud. This service improves performance through caching, where web applications allow you to retrieve information from fast, managed, in-memory data stores instead of relying entirely on slower disk-based solutions.

Question 6

Which AWS service is a fully managed, serverless, NoSQL database that has been built to run high-performance applications at any scale?

A. Amazon S3

B. Amazon RDS Proxy

C. Amazon Aurora

D. Amazon DynamoDB

Answer 6

D. Amazon DynamoDB

Explanation:
DynamoDB is a fully managed, serverless, NoSQL database that has been built to run high-performance applications at any scale.

Question 7

Amazon QLDB is a _____ database.
A. relational
B. document
C. ledger
D. graph

Answer 7

C. ledger

Explanation:
What actually is Amazon QLDB? It’s yet another fully managed and serverless database service, which has been designed as a ledger database.

Question 8

_______________ allows you to set up your secure data lake by identifying existing data sources that you want to move into your data lake, and then crawling, cataloging, and preparing all that data for you to perform analytics on.
A. AWS Lake Formation
B. Amazon Athena
C. Amazon OpenSearch Service
D. AWS Glue

Answer 8

A. AWS Lake Formation

Explanation:
We can use the AWS Lake Formation service, which promises to make setting up your secure data lake take only a matter of days, instead of weeks or months. It does this by identifying existing data sources within Amazon S3, relational databases, and NoSQL databases that you want to move into your data lake. It then will crawl and catalog and prepare all that data for you to perform analytics on.

Question 9

Amazon Keyspaces is compatible with _____.
A. MongoDB
B. MySQL
C. Firebase
D. Apache Cassandra

Answer 9

D. Apache Cassandra

Explanation:
Keyspaces is a serverless, fully-managed service designed to be highly scalable, highly available, and, importantly, compatible with Apache Cassandra, meaning you can use all the same tools and code as you do normally with your existing Apache Cassandra databases.

Question 10

Amazon Redshift operates as a _____ database management system.
A. NoSQL
B. relational
C. object
D. graph

Answer 10

B. relational

Explanation:
Redshift operates as a relational database management system, and therefore is compatible with other RDBMS applications.

Question 11

Which Amazon RDS database engine deploys a database cluster across multiple availability zones, to serve as the primary instance’s storage layer?
A. PostgreSQL
B. MySQL
C. Oracle
D. Aurora

Answer 11

D. Aurora

Explanation:
When you create an Amazon Aurora instance, the Aurora service also deploys a cloud-native database cluster, and the Aurora instances will use this database cluster as the underlying data store. The database cluster spans two or more availability zones by default, with each availability zone having a copy of the database cluster data. And each cluster has one primary instance which performs all of the data modifications to the cluster volume and supports read and write operations.

Question 12

In which two general families can you classify all AWS database services?

A. Relational and non-relational

B. Structured and unstructured

C. Persistent and in-memory

D. Managed and unmanaged

Answer 12

A. Relational and non-relational

Explanation:
The two general families are relational and non-relational and non-relational. Relational includes Amazon RDS and its various database engine options, as well as Amazon Redshift. Non-relational includes DynamoDB, Elasticache, and Neptune, among others.

Question 13

Which of the following AWS databases is a managed NoSQL graph database?

A. Amazon Neptune

B. Amazon DynamoDB

C. Amazon DocumentDB

D. Amazon Keyspaces

Answer 13

A. Amazon Neptune

Explanation:
The AWS managed NoSQL graph database is Amazon Neptune.

Graph databases are composed of three elements, vertices, edges, and properties.

Vertices, also called nodes, are objects such as people or artifacts. Each node in a graph database has a unique identifier expressed in key-value pairs.

The singular of vertices is vertex. A vertex can represent data such as integers, string, people, locations, and buildings.

Edges represent the connection–or relationship–between two objects. Each edge is defined by a unique identifier that provides details about a starting or ending node along with a set of properties.

The vertices and edges can each have properties associated with them. This allows a graph database to depict complex relationships between otherwise unrelated data.

Question 14

Amazon Redshift is a fast, fully-managed, _____-scale data warehouse.
A. megabyte
B. gigabyte
C. terabyte
D. petabyte

Answer 14

D. petabyte

Explanation:
Amazon Redshift is a fast, fully-managed, petabyte-scale data warehouse.

Question 15

Which of the following AWS databases stores, queries, and indexes JSON data?
A. Amazon Aurora
B. Amazon Redshift
C. Amazon QLDB
D. Amazon DocumentDB

Answer 15

D. Amazon DocumentDB

Explanation:
Amazon DocumentDB is a document database. Document databases store semi-structured data and the data structure is embedded in the document, itself. As a document database, Amazon DocumentDB is designed to store, query, and index JSON data.

Question 16

Which of the following is an AWS managed service providing relational databases with a variety of database engines?
A. Amazon QLDB
B. Amazon DocumentDB
C. Amazon Elasticache
D. Amazon RDS

Answer 16

D .Amazon RDS

Explanation:
They fall into two primary categories, relational and NoSQL databases. The Amazon Relational Database Service is the managed service providing relational databases. The engines include Amazon Aurora, MySQL, MariaDB, Postgres, Microsoft SQL Server, and Oracle.

Question 17

What are two types of databases offered by AWS?

A. Relational and Non-relational (NoSQL)

B. Object and Block

C. Persistent and In-memory

D. Stateful and Stateless

Answer 17

A. Relational and Non-relational (NoSQL)

Explanation:
Database services allow you to choose from a range of database options to power your applications. These include traditional relational databases or relational database management systems, RDBMS, as well as non-relational databases, often called NO SQL, not only SQL databases.

Question 18

What are the advantages of hosting databases on Amazon RDS instead of Amazon EC2? (Choose 3 answers)

A.Managed failover in the event of DB failure

B. Automated database patching

C. Managed hardware lifecycle

D. Automated DB backup

Answer 18

A. Managed failover in the event of DB failure

Automated database patching

Automated DB backup

Explanation:
Amazon RDS provides the following specific advantages over database deployments that aren’t fully managed:

You can use the database products you are already familiar with: MariaDB, Microsoft SQL Server, MySQL, Oracle, and PostgreSQL.
Amazon RDS manages backups, software patching, automatic failure detection, and recovery.
You can turn on automated backups, or manually create your own backup snapshots. You can use these backups to restore a database. The Amazon RDS restore process works reliably and efficiently.
You can get high availability with a primary instance and a synchronous secondary instance that you can fail over to when problems occur. You can also use read replicas to increase read scaling.
In addition to the security in your database package, you can help control who can access your RDS databases by using AWS Identity and Access Management (IAM) to define users and permissions. You can also help protect your databases by putting them in a virtual private cloud (VPC).

Question 19

Which of the following statements about data lakes and data warehouses is true?
A. A data warehouse is a formless blob of information.
B. A data warehouse is a specialized tool that allows you to perform analysis on a portion of data from a data lake.
C. Generally, a data lake is a subset of the data from a data warehouse with a specialized purpose.
D. A data lake is an optimized database dealing with normalized, transformed, and cleaned-up versions of the data from a data warehouse.

Answer 19

B. A data warehouse is a specialized tool that allows you to perform analysis on a portion of data from a data lake.

Explanation:
A data lake is a formless blob of information. It is a pool of knowledge where we try to capture any relevant data from our business so that we can perform analytics on it. A data warehouse is a specialized tool that allows you to perform analysis on a portion of that data, so you can make meaningful decisions from it. Generally, it is a subset of the data from the data lake with a specialized purpose. Your data warehouse Is an optimized database that is dealing with normalized, transformed, and cleaned-up versions of the data from the data lake.

Question 20

Each of the following is a use case for Amazon ElastiCache except which choice?
A. persistent data storage
B. in-memory data storage
C. improving read access performance
D. caches using secure, network-attached RAM

Answer 20

A. persistent data storage

Explanation:
ElastiCache should never be used to store your only version of data records, since a cache is designed to be a temporary data store. So when data persistence is necessary, such as when we are working with primary data records, or when we need write performance rather than read performance, a persistent data store should be used instead of an ElastiCache.