Book Image

Amazon SimpleDB Developer Guide

Book Image

Amazon SimpleDB Developer Guide

Overview of this book

SimpleDB is a highly scalable, simple-to-use, and inexpensive database in the cloud from Amazon Web Services. But in order to use SimpleDB, you really have to change your mindset. This isn't a traditional relational database; in fact it's not relational at all. For developers who have experience working with relational databases, this may lead to misconceptions as to how SimpleDB works.This practical book aims to address your preconceptions on how SimpleDB will work for you. You will be quickly led through the differences between relational databases and SimpleDB, and the implications of using SimpleDB. Throughout this book, there is an emphasis on demonstrating key concepts with practical examples for Java, PHP, and Python developers.You will be introduced to this massively scalable schema-less key-value data store: what it is, how it works, and why it is such a game-changer. You will then explore the basic functionality offered by SimpleDB including querying, code samples, and a lot more. This book will help you deploy services outside the Amazon cloud and access them from any web host.You will see how SimpleDB gives you the freedom to focus on application development. As you work through this book you will be able to optimize the performance of your applications using parallel operations, caching with memcache, asynchronous operations, and more.
Table of Contents (16 chapters)
Amazon SimpleDB Developer Guide
Credits
Foreword
About the Authors
About the Reviewers
Preface

Exploring the metadata for a domain and costs


Every call made to SimpleDB, irrespective of whether the operation works on a domain or an item, always returns two specific values associated with it. These values are automatically provided within the response. They exist for all operations, and for every invocation of the operation in SimpleDB:

  • RequestId: A unique ID for tracking the request made to SimpleDB. This is also very useful for debugging purposes. If you are having any issues with your calls to SimpleDB and are unable to determine the cause or reason from your side, this is the ID that you need to give AWS as a part of the debug information to facilitate tracing the request.

  • BoxUsage: SimpleDB measures the machine utilization of each request and charges the customer based on the amount of machine capacity used to complete the particular request (SELECT, GET, PUT, and so on), normalized to the hourly capacity of a circa 2007 1.7 GHz Xeon processor. This measure is named as BoxUsage...