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

Logic flow for using caching with SimpleDB


Here is the flow of logic when we use memcached with SimpleDB:

  1. 1. When you need to retrieve data from SimpleDB, first query memcached server to see if the data is currently available in the cache.

  2. 2. If the data is in the cache, then simply return the data, and do not make a request to SimpleDB.

  3. 3. If the data is not in the cache, retrieve it from SimpleDB, and store it in the cache before returning the results back, so it is available next time you need it in the cache.

  4. 4. If you are updating the data, all you have to do is update SimpleDB and also delete the data from the cache. This will ensure that the next request from the data will get the latest information from SimpleDB and not outdated information from the cache. You can also just update the cache with the latest data that you have, thus alleviating any issue with eventual consistency, returning stale data when you turn around and make a request immediately.

  5. 5. If you have data that automatically...