Book Image

AWS Certified Database – Specialty (DBS-C01) Certification Guide

By : Kate Gawron
5 (1)
Book Image

AWS Certified Database – Specialty (DBS-C01) Certification Guide

5 (1)
By: Kate Gawron

Overview of this book

The AWS Certified Database – Specialty certification is one of the most challenging AWS certifications. It validates your comprehensive understanding of databases, including the concepts of design, migration, deployment, access, maintenance, automation, monitoring, security, and troubleshooting. With this guide, you'll understand how to use various AWS databases, such as Aurora Serverless and Global Database, and even services such as Redshift and Neptune. You’ll start with an introduction to the AWS databases, and then delve into workload-specific database design. As you advance through the chapters, you'll learn about migrating and deploying the databases, along with database security techniques such as encryption, auditing, and access controls. This AWS book will also cover monitoring, troubleshooting, and disaster recovery techniques, before testing all the knowledge you've gained throughout the book with the help of mock tests. By the end of this book, you'll have covered everything you need to pass the DBS-C01 AWS certification exam and have a handy, on-the-job desk reference guide.
Table of Contents (24 chapters)
1
Part 1: Introduction to Databases on AWS
Free Chapter
2
Chapter 1: AWS Certified Database – Specialty Overview
5
Part 2: Workload-Specific Database Design
12
Part 3: Deployment and Migration and Database Security
16
Part 4: Monitoring and Optimization
20
Part 5: Assessment
21
Chapter 16: Exam Practice

Understanding DynamoDB pricing and limits

DynamoDB is a serverless managed service, which means you do not pick an instance size to control the performance. Instead, DynamoDB is charged based on how much data you read and write to your table. DynamoDB has four main components to its pricing:

  • Read request units
  • Write request units
  • Storage
  • Additional features such as DAX, global tables, and streams

Let's start by looking at read and write capacity units.

Request units

Request units are the main usage mechanism within DynamoDB. The number of requests you need for each task will depend on the amount of data being returned as well as the read/write type:

  • One read request will give you one strongly consistent read request or two eventually consistent requests for every 4 KB of data.
  • Two read requests will give you one transactional read for every 4 KB of data.
  • One write request will give you one standard write for every 1 KB of data...