9 - The Core Database Services Flashcards by Kaman Hung

What is the impact of database choice on applications?

The type of database and its configuration significantly impact the performance and availability of database-backed applications.

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What are managed database services offered by AWS?

AWS offers the following managed database services:
* Relational database service (RDS)
* DynamoDB
* Redshift

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What is the main determinant for choosing a database model?

The needs of the application determine the database model you choose.

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What are the fundamental components of a relational database?

A relational database consists of tables, which contain columns (attributes) and rows (records).

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How is uniqueness of rows ensured in a relational database?

Uniqueness is ensured by defining a primary key, which must be unique and present in each record.

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What is the advantage of storing structured data in a relational database?

You can quickly search the entire database for specific values and perform complex queries.

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What language do relational databases primarily use?

Relational databases primarily use Structured Query Language (SQL).

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What does the SELECT statement do in SQL?

The SELECT statement reads data from the database and controls how it’s formatted.

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What does the INSERT statement do in SQL?

The INSERT statement writes data to a table.

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What is a defining characteristic of nonrelational (NoSQL) databases?

Nonrelational databases are schemaless and can store unstructured data.

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What is the primary key’s role in nonrelational databases?

The primary key uniquely identifies each item in a nonrelational database.

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What is the purpose of Amazon ElastiCache?

ElastiCache moves frequently accessed data closer to clients for quicker retrieval.

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What are the two engines available for ElastiCache?

ElastiCache can be created using either Memcached or Redis.

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What distinguishes Amazon MemoryDB from ElastiCache?

Amazon MemoryDB is a standalone Redis database that provides persistent storage and caching.

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What is Amazon RDS?

Amazon RDS is a managed relational database service that allows provisioning of various RDBMS.

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What are the advantages of using Amazon RDS?

Advantages include automated setup, maintenance, backups, and support for multiple availability zones.

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What are the supported database engines in Amazon RDS?

Amazon RDS supports:
* MySQL
* MariaDB
* Oracle
* PostgreSQL
* Microsoft SQL Server
* Amazon Aurora

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What are the two licensing options for RDS database engines?

The two licensing options are:
* License Included
* Bring Your Own License (BYOL)

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What is the purpose of instance classes in Amazon RDS?

Instance classes define the number of virtual CPUs, memory, and throughput for RDS instances.

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What are the three instance classes available in RDS?

The three instance classes are:
* Standard
* Memory Optimized
* Burstable Performance

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What does scaling vertically mean in the context of RDS?

Scaling vertically means changing the resource allocation to a specific instance, either scaling up or down.

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What determines the performance level of an RDS instance?

The performance level is determined by the instance class and the type of storage used.

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What factors affect the performance of an RDS instance?

The instance class and the type of storage used

EBS volumes and their IOPS support also play a significant role.

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What are the three types of storage offered by RDS?

General-purpose SSD
Provisioned IOPS SSD
Magnetic

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What is the size range for general-purpose SSD storage in RDS?

20 GB to 32 TB

What is 'bursting' in the context of general-purpose SSD storage?

A temporary increase in IOPS during spikes of heavy read or write activity

What distinguishes provisioned IOPS SSD storage from general-purpose SSD storage?

You can specify the exact number of IOPS you want to allocate per volume.

What is the maximum size of a magnetic storage volume in RDS?

4 TB

Can you decrease the size of an EBS volume after creating it?

No, you cannot decrease the amount of storage allocated.

What is a read replica in RDS?

An additional RDS instance that performs only reads from the database.

What is the primary benefit of using read replicas?

They help improve performance by offloading read-only queries from the master instance.

What feature in RDS ensures high availability?

Multi-AZ feature

How does Multi-AZ feature enhance database availability?

It creates a standby database instance in a different availability zone.

What happens during a failover in Multi-AZ configuration?

RDS automatically switches to the standby instance.

What is the expected monthly availability of a database with Multi-AZ enabled?

99.95 percent

What is the purpose of RDS snapshots?

To take manual or automatic backups of your instances.

What is the difference between snapshots and Multi-AZ?

Snapshots restore an entire database instance; Multi-AZ keeps databases running during instance failures.

What is the Recovery Point Objective (RPO)?

How much data loss you can tolerate in the event of a failure.

What tools can you use to migrate an existing SQL database to RDS?

* AWS Database Migration Service (DMS) * AWS Schema Conversion Tool (SCT)

What is DynamoDB?

Amazon’s managed nonrelational database service.

What is the basic unit of organization in DynamoDB?

Item

What must each item in DynamoDB have?

A unique value for the primary key.

What are the two main types of data types in DynamoDB?

* Scalar data * Document data

What does DynamoDB use to distribute items across multiple partitions?

The primary key

What is Redshift?

A managed relational database specifically designed as a data warehouse.

What is Redshift Spectrum?

A feature that allows you to analyze data stored in S3.

What is the maximum data storage capacity using dense storage nodes in Redshift?

2 PB

How many compute nodes can a Redshift cluster have?

At least 1 and up to 128 nodes.

What is the maximum storage Redshift can achieve using dense compute nodes?

326 TB

What types of data can Redshift analyze?

* Structured data from other relational databases * Data from Amazon S3

What is Redshift Spectrum?

A feature of Redshift that lets you analyze data stored in S3 with a defined structure.

Name three AWS analytics services.

* Amazon Kinesis * Amazon EMR * Amazon OpenSearch Service

What is Amazon Kinesis?

A collection of services that let you collect, process, store, and deliver streaming data.

What types of data can Kinesis Video Streams handle?

* Image recognition * Streaming video * Teleconferencing

What is the role of a producer in Kinesis Video Streams?

The data source that feeds data into a Kinesis stream.

What is Kinesis Data Streams?

A data pipeline that can aggregate, buffer, and reliably store data from producers until a consumer is ready to process it.

What types of data can Kinesis Data Streams rapidly ingest?

* Server logs * Social media feeds * Financial transactions * Location information

What is the purpose of sequence numbers in Kinesis Data Streams?

To uniquely identify each record and maintain order for data that may not be time-dependent.

What is fan-out in Kinesis Data Streams?

A process where multiple consumers can read from a stream concurrently.

What does Kinesis Data Firehose do?

Ingests streaming data and transforms it before sending it to a destination.

How does Kinesis Data Analytics function?

Allows you to create custom applications to process and analyze streaming data using languages like Java, Scala, Python, or SQL.

What is Amazon MSK?

A streaming data platform that uses Apache Kafka for event streaming.

What is Amazon Elastic MapReduce (Amazon EMR)?

A service that allows you to run various big data framework clusters in the cloud.

List some frameworks supported by Amazon EMR.

* Apache Hadoop * Apache Spark * Apache Flink * Apache Presto * TensorFlow

What is OpenSearch?

An open source fork of ElasticSearch that offers full-text search capabilities.

What is AWS Data Exchange?

A repository of third-party datasets for analysis covering various sectors.

What are the two main types of databases discussed?

* Relational databases * Nonrelational databases

What is a primary key in a nonrelational database?

A unique identifier for each item in the database.

What are the scaling options for RDS?

* Vertical scaling by upgrading instance class * Horizontal scaling using read replicas

How does DynamoDB store data?

As items in tables, each with a unique primary key.

What is the maximum data storage capacity of Redshift?

Up to 2 PB.