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Augusto Valdivia for AWS Community Builders

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The Non-Relational DB(NoSQL)

What is a Non-Relational DB?

As we learned about The relational dbs and their relational model on my earlier article. The Non-relational database also known as NoSQL is a database that does not follow the this model instead follows a key-value structure.

How does one know when to choose a Non-Relational DB?

If part of your daily tasks requires manipulating and analyzing all sizes of complex and unstructured data with a lot of flexibility, then NoSQL is your best choice.

What are some industries Non-Relational DB use cases?

  • Websites, Ecommerce systems and Apps (Think about customers interaction)

    • Credit cards (history)
    • Real-time bidding
    • Shopping cart
    • Social
    • Product catalog
    • Customer preferences
    • High-traffic

website

Now that we have a general idea of Non-Relational databases let us continue drilling deeper and let us explore and build AWS Non-Relational resources:

  • Amazon DynamoDB

What is Amazon Amazon DynamoDB?

Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability. DynamoDB lets you offload the administrative burdens of operating and scaling a distributed database so that you don't have to worry about hardware provisioning, setup and configuration, replication, software patching, or cluster scaling.

Let us see some important characteristics about Amazon DynamoDB


Performance: 

- More than 10 trillion requests per day
- Database tables can store and retrieve any amount of data and serve any level of request traffic
- Provides on-demand backup capability and enable point-in-time recovery of DynamoDB tables
- 20 million requests per second
- Can restore a table to any point in time during the last 35 days
- Global table replication
- Availability to switch between read/write capacity modes once every 24 hours.
- No need to change any code or applications to use or manage encrypted tables.

Scalability: 

- Automatic data replication over three availability-zones in a single region
- Scale up or down tables throughput capacity with zero downtime or performance degradation


Availability:

 - Maximum size per item is 400KB
 - 2,500 tables per AWS Region
 - Read/write capacity mode: 

 Capacity unit sizes for provisioned tables:

     - One read capacity unit = one strongly consistent read per second, or two eventually consistent reads per second, for items up to 4 KB in size.
     - One write capacity unit = one write per second, for items up to 1 KB in size.
     - Transactional read requests require two read capacity units to perform one read per second for items up to 4 KB.
     - Transactional write requests require two write capacity units to perform one write per second for items up to 1 KB.

 Request unit sizes for on-demand tables:

     - One read request unit = one strongly consistent read, or two eventually consistent reads, for items up to 4 KB in size.
     - One write request unit = one write, for items up to 1 KB in size.
     - Transactional read requests require two read request units to perform one read for items up to 4 KB.
     - Transactional write requests require two write request units to perform one write for items up to 1 KB. 

- Throughput capacity: 

  - On-Demand:
    - Per table
      1. 40,000 read request units and 40,000 write request units

    - Per account
      1. Not applicable

    - Minimum throughput for any table or global secondary index
      1. Not applicable

  - Provisioned:
    - Per table
      1. 40,000 read request units and 40,000 write request units

    - Per account
      1. 80,000 read capacity units and 80,000 write capacity units

    - Minimum throughput for any table or global secondary index
      1. read capacity unit and 1 write capacity unit


Security: 

  - DynamoDB encryption at rest provides enhanced security by encrypting all your data at rest using encryption keys stored in AWS Key Management Service (AWS KMS)
  - AWS owned key – Default encryption type. The key is owned by DynamoDB (no additional charge).
  - AWS managed key – The key is stored in your account and is managed by AWS KMS (AWS KMS charges apply).
  - Customer managed key – The key is stored in your account and is created, owned, and managed by you. You have full control over the KMS key (AWS KMS charges apply).
  - Can switch between the AWS owned key, AWS managed key, and customer managed key at any given time.
  - IAM administrators control who can be authenticated (signed in) and authorized (have permissions) to use Amazon DynamoDB resources.
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Please note that some of these limitations are adjustable and others are not.

As you can see throughout these characteristics DynamoDB makes a perfect tool for developers 👩‍💻.

Oh, right it is building 👷 time let us build this database using Terraform

db

Find the Terraform repo and directions for this project here

Terraform code previous:

resource "aws_dynamodb_table" "dynamodb-table" {
  name           = "GameScores"
  billing_mode   = "PROVISIONED"
  read_capacity  = 20
  write_capacity = 20
  hash_key       = "UserId"
  range_key      = "GameTitle"

  attribute {
    name = "UserId"
    type = "S"
  }

  attribute {
    name = "GameTitle"
    type = "S"
  }

  attribute {
    name = "TopScore"
    type = "N"
  }

  ttl {
    attribute_name = "TimeToExist"
    enabled        = false
  }

  global_secondary_index {
    name               = "GameTitleIndex"
    hash_key           = "GameTitle"
    range_key          = "TopScore"
    write_capacity     = 10
    read_capacity      = 10
    projection_type    = "INCLUDE"
    non_key_attributes = ["UserId"]
  }

}
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Diagram

DDB

References:

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/identity-and-access-mgmt.html

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