You are previewing Programming Amazon Web Services.

Programming Amazon Web Services

Cover of Programming Amazon Web Services by James Murty Published by O'Reilly Media, Inc.
  1. Programming Amazon Web Services
    1. SPECIAL OFFER: Upgrade this ebook with O’Reilly
    2. A Note Regarding Supplemental Files
    3. Preface
      1. What’s in This Book?
      2. Ruby and Interactive Examples
      3. Conventions Used in This Book
      4. Using Code Examples
      5. Safari® Enabled
      6. How to Contact Us
      7. Acknowledgments
    4. 1. Infrastructure in the Cloud
      1. Amazon Web Services for Infrastructure
      2. Thinking Like Amazon
      3. Reality Check
      4. Interfaces: REST and Query Versus SOAP
    5. 2. Interacting with Amazon Web Services
      1. REST-Based APIs
      2. User Authentication
      3. Performing AWS Requests
    6. 3. S3: Simple Storage Service
      1. S3 Overview
      2. Interacting with S3
      3. Buckets
      4. Objects
      5. Alternative Hostnames
      6. Access Control Lists
      7. Server Access Logging (Beta)
      8. Signed URIs
      9. Distributing Objects with BitTorrent
    7. 4. S3 Applications
      1. Share Large Files
      2. Online Backup with AWS::S3
      3. S3 Filesystem with ElasticDrive
      4. Mediated Access to S3 with JetS3t
    8. 5. EC2: Elastic Compute Cloud (Beta)
      1. EC2 Overview
      2. Interacting with EC2
      3. Keypairs
      4. Network Security by IP
      5. Finding Amazon Machine Images
      6. Controlling Instances
      7. Log In to an Instance
      8. Security Groups
      9. Managing and Sharing AMIs
      10. Console Output and Instance Reboot
    9. 6. Using EC2 Instances and Images
      1. EC2 Instances in Detail
      2. Data Management in EC2
      3. Modifying an AMI
      4. Registering an AMI
      5. Create an AMI from Scratch
    10. 7. EC2 Applications
      1. Dynamic DNS
      2. On-Demand VPN Server with OpenVPN
      3. Web Photo Album with Gallery 2
    11. 8. SQS: Simple Queue Service
      1. SQS Overview
      2. Interacting with SQS
      3. Queues
      4. Messages
      5. Queue Attributes
      6. Queue Access Control
    12. 9. SQS Applications
      1. Messaging Simulator
      2. Distributed Application Services with BOTO
      3. Automated Management of EC2 Instance Pools with Lifeguard
    13. 10. FPS: Flexible Payments Service (Beta)
      1. FPS Overview
      2. Interacting with FPS
      3. Managing Your Tokens
      4. Acquiring Third-Party Tokens
      5. Pay Now Widgets
    14. 11. FPS Transactions and Accounts
      1. Performing FPS Transactions
      2. Account Management and Information
    15. 12. FPS Advanced Topics
      1. Gatekeeper Language Guide
      2. Micropayments with FPS
      3. Building a Marketplace Application
      4. Subscribing to FPS Event Notifications
    16. 13. SimpleDB (Beta)
      1. SimpleDB Overview
      2. Interacting with SimpleDB
      3. Domains
      4. Items and Attributes
      5. Representing Data in SimpleDB
      6. Performing Queries
      7. Stock Price Database: A Mini SimpleDB Application
    17. A. AWS Resources
      1. AWS Online Resources
      2. Client Tools
      3. API Libraries
      4. Third-Party AWS Solutions
    18. B. AWS API Error Codes
      1. S3: Simple Storage Service
      2. EC2: Elastic Compute Cloud
      3. SQS: Simple Queue Service
      4. FPS: Flexible Payments Service
      5. SimpleDB
    19. Index
    20. About the Author
    21. Colophon
    22. SPECIAL OFFER: Upgrade this ebook with O’Reilly
O'Reilly logo

Items and Attributes

Information is stored in the SimpleDB service as a collection of attribute values that are grouped together as items, where each item comprises one or more attributes. Items and attributes are inseparable resources; they cannot exist independently, nor can they be manipulated in isolation. The SimpleDB API operations we will discuss in this section all operate on items and attributes at the same time.

Items

An item is a collection of attributes with a name that is unique within the domain to which it belongs. The name can contain any text in UTF-8 format and may be between 1 and 1024 bytes long. An item’s name serves as its unique identifier. Although the item name is similar in concept to a primary key column in a traditional database, there is an important difference: you cannot refer to item names in SimpleDB query statements.

Each item may contain up to 256 attribute values. Note that this limit applies to attribute name and value pairs, not just attribute names. This means that attributes with multiple values will use up more than one of the 256 spaces allowed. Because an item must always contains at least one attribute value, you cannot create an item without specifying at least one; and if all of an item’s attribute values are deleted, the item is automatically deleted as well.

You may alter the attributes stored in an item at any time, and because the SimpleDB service does not impose a schema, there is no requirement that the items in a domain contain matching ...

The best content for your career. Discover unlimited learning on demand for around $1/day.