AWS Security  |  Contact Us  |  Create an AWS Account Create an AWS Account
Amazon Web Services
Home > Products > Amazon SimpleDB > FAQs

Q: What is Amazon SimpleDB?
Amazon SimpleDB is a web service providing the core database functions of data indexing and querying.
Q: What can I do with Amazon SimpleDB?
Amazon SimpleDB provides a simple web services interface to create and store multiple datasets, query your data easily, and return the results. This service works in close conjunction with Amazon Simple Storage Service (Amazon S3) and Amazon Elastic Compute Cloud (Amazon EC2), collectively providing the ability to store, process and query data sets in the cloud. These services are designed to make web-scale computing easier and more cost-effective for developers.
Q: How can I get started with Amazon SimpleDB?
To sign up for Amazon SimpleDB, click the “Sign up for This Web Service” button on the Amazon SimpleDB detail page. You must have an Amazon Web Services account to access this service; if you do not already have one, you will be prompted to create one when you begin the Amazon SimpleDB sign-up process. After signing up, the best way to understand Amazon SimpleDB is to work through the Getting Started Guide, part of our Technical Documentation. Within a few minutes, you will be able to create your domain and begin storing and querying your data!
Q: What are the technical benefits of Amazon SimpleDB?
Amazon SimpleDB requires no schema, automatically indexes your data and provides a simple API for storage and access. This eliminates the administrative burden of data modeling, index maintenance, and performance tuning. Developers gain access to this functionality within Amazon’s proven computing environment, are able to scale instantly, and pay only for what they use.
Q: What can developers do now that they could not before?
Traditionally, this type of functionality has been accomplished with a clustered relational database that requires a sizable upfront investment, brings more complexity than is typically needed, and often requires a DBA to maintain and administer. In contrast, Amazon SimpleDB is easy to use and provides the core functionality of a database – real-time lookup and simple querying of structured data – without the operational complexity.
Q: What is the relationship between Amazon SimpleDB and traditional relational databases?

Today, many developers correlate the word “database” with Relational Database Management Systems (RDBMS). While RDBMS offerings provide deep functionality, for many use cases, they introduce more complexity (and more cost) than is necessary. Many developers simply want to store, process, and query their data without worrying about managing schemas, maintaining indexes, tuning performance or scaling access to their data. Amazon SimpleDB removes the need to maintain a schema, while your attributes are automatically indexed to provide fast real-time lookup and querying capabilities. This flexibility minimizes the performance tuning required as the demands for your data increase.

Some developers do require a complex schema or broader functionality, and will undertake the extra work required to run their own relational database. Many developers are doing just this by hosting their own databases inside the Amazon EC2 compute environment. This provides them complete control over whatever database they choose to run, while still accessing the benefits of Amazon’s computing infrastructure and the ability to scale capacity up and down instantly.

Either choice is fine with us. Over time, we plan to continue to add features that make it as easy as possible for developers to pursue whichever option they prefer for obtaining database functionality.
Q: When should I use Amazon S3 vs. Amazon SimpleDB?

Unlike Amazon S3, Amazon SimpleDB is not storing raw data. Rather, it takes your data as input and expands it to create indices across multiple dimensions, which enables you to quickly query that data. Additionally, Amazon S3 and Amazon SimpleDB use different types of physical storage. Amazon S3 uses dense storage drives that are optimized for storing larger objects inexpensively. Amazon SimpleDB stores smaller bits of data and uses less dense drives that are optimized for data access speed.

In order to optimize your costs across AWS services, large objects or files should be stored in Amazon S3, while smaller data elements or file pointers (possibly to Amazon S3 objects) are best saved in Amazon SimpleDB. Because of the close integration between services and the free data transfer within the AWS environment, developers can easily take advantage of both the speed and querying capabilities of Amazon SimpleDB as well as the low cost of storing data in Amazon S3, by integrating both services into their applications.
Q: What kind of data can I store?
You can store any UTF-8 string data in Amazon SimpleDB. Please refer to the Amazon Web Services Customer Agreement for details.
Q: How much data can I store?
Individual item names, attribute names, and attribute values can be up to 1,024 bytes in length. Amazon SimpleDB allows 10GB of storage for each domain with 100 domains per customer account, which provides you with 1 TB of total storage. Please complete this form if your application requires more storage.
Q: Where is my data stored?
Amazon SimpleDB stores your data in our multiple data centers in the United States. We anticipate adding other geographies over time.
Q: What does Amazon do with my data in Amazon SimpleDB?
Amazon will store your data and track its associated usage for billing purposes. Amazon will not otherwise access your data for any purpose, except when required to do so by law. Please refer to the Amazon Web Services Customer Agreement for details.
Q: Does Amazon store its own data in Amazon SimpleDB?
Yes. Developers within Amazon use Amazon SimpleDB for a wide variety of projects. Many of these projects use Amazon SimpleDB as their authoritative data and query store and rely on it for business-critical operations.
Q: How much does Amazon SimpleDB cost?

You can get started with SimpleDB for free and without risk. For at least the first six months of the public beta (starting December 1, 2008), you pay no charges on the first 25 Machine Hours, 1 GB of Data Transfer, and 1 GB of Storage that you consume every month. Amazon SimpleDB lets developers pay only for what they consume and there is no minimum fee.

Machine Utilization

  • First 25 Amazon SimpleDB Machine Hours consumed per month are free
  • $0.14 per Amazon SimpleDB Machine Hour consumed thereafter

Amazon SimpleDB measures the machine utilization of each request and charges based on the amount of machine capacity used to complete the particular request (QUERY, GET, PUT, etc.), normalized to the hourly capacity of a circa 2007 1.7 GHz Xeon processor.

Data Transfer

  • First 1 GB of data transferred in per month is free
  • $0.100 per GB – all data transfer in thereafter
  • First 1 GB of data transferred out per month is free; thereafter:
  • $0.170 per GB – first 10 TB / month data transfer out
  • $0.130 per GB – next 40 TB / month data transfer out
  • $0.110 per GB – next 100 TB / month data transfer out
  • $0.100 per GB – data transfer out / month over 150 TB

Data transfer “in” and “out” refers to transfer into and out of Amazon SimpleDB. Data transferred between Amazon SimpleDB and other Amazon Web Services is free of charge (i.e., $0.00 per GB).

Structured Data Storage

  • First 1 GB stored per month is free
  • $0.25 per GB-month thereafter

Amazon SimpleDB measures the size of your billable data by adding the raw byte size of the data you upload + 45 bytes of overhead for each item, attribute name and attribute-value pair.

Q: What are some pricing examples?

The following examples refer to charges for usage beyond the free usage levels described above. As previously described, usage below the monthly free tier is provided at no charge.

Machine Utilization:
Amazon SimpleDB measures the machine utilization of each request and charges based on the amount of machine capacity used to complete the particular request (QUERY, GET, PUT, etc.), normalized to the hourly capacity of a circa 2007 1.7 GHz Xeon processor. Machine utilization is driven by the amount of data (# of attributes, length of attributes) processed by each request. A GET operation that retrieves 256 attributes will use more resources than a GET that retrieves only 1 attribute. A multi-predicate QUERY that examines 100,000 attributes will cost more than a single predicate query that examines 250.

In the response message for each request, Amazon SimpleDB returns a field called Box Usage. Box Usage is the measure of machine resources consumed by each request. It does not include bandwidth or storage. Box usage is reported as the portion of a machine hour used to complete a particular request. The cost of an individual request is Box Usage (expressed in hours) * $0.14 per Amazon SimpleDB Machine hour. The cost of all your requests is the sum of Box Usage (expressed in hours) * $0.14.

For example, if over the course of a month, the sum of the Box Usage for your requests uses the equivalent of one 1.7 GHz Xeon processor for 9 hours, your charge will be:

9 hours * $0.14 per Amazon SimpleDB Machine hour = $1.26.

Network Data Transferred:
(i) $0.10 per GB data transfer in

This charge is for the amount of data sent to Amazon SimpleDB, and applies whenever data is written to any of your domains.

Transfer In Example:
You upload 500 MB of data to Amazon SimpleDB each day during the month of March.

Total Data Transfer In for the month = 500 MB x (1 GB / 1024 MB) x 31 days = 15.14 GB

Total Charge = 15.14 GB x ($0.10 / GB) = $1.52

(ii) $0.17 per GB data transfer out for the first 10 TB, $0.13 per GB for the next 40 TB, $0.11 per GB for the next 100 TB, and $0.10 for all remaining data transfer out of Amazon SimpleDB in a month

This charge is for the amount of data retrieved from Amazon SimpleDB, and applies whenever data is read from any of your domains.

Transfer Out Example:

You transfer 500 MB of data out of Amazon SimpleDB each day during the month of March.

Total Data Transfer Out for the month = 500 MB x (1 GB / 1,024 MB) x 31 days = 15.14 GB

Total charge = 15.14 GB x ($0.17 / GB) = $2.58

Storage
The best way to predict the size of your structured data storage is as follows:

Raw byte size (GB) of all item IDs + 45 bytes per item + Raw byte size (GB) of all attribute names + 45 bytes per attribute name + Raw byte size (GB) of all attribute-value pairs + 45 bytes per attribute-value pair

To calculate your estimated monthly storage cost, take the resulting size in GB and multiply by $0.25.
Q: How will I be charged and billed for my use of Amazon SimpleDB?
There are no set-up fees or commitments to begin using the service. Following the end of the month, your credit card will automatically be charged for that month’s usage. You can view your charges for the current billing period at any time on the AWS web site, by logging into your Amazon Web Services account, and clicking “Account Activity” under “Your Web Services Account”.
Q: How is Amazon SimpleDB data organized?

You organize your structured data into domains and can run queries across all of the data stored in a particular domain. Domains are comprised of items, and items are described by attribute-value pairs. To understand these elements, consider the metaphor of data stored in a spreadsheet table. An Amazon SimpleDB domain is like a worksheet, items are like rows of data, attributes are like column headers, and values are the data entered in each of the cells.

However unlike a spreadsheet, Amazon SimpleDB allows for multiple values to be associated with each “cell” (e.g., for item “123,” the attribute “color” can have both value “blue” and value “red”). Additionally, in Amazon SimpleDB, each item can have its own unique set of associated attributes (e.g., item “123” might have attributes “description” and “color” whereas item “789” has attributes “description,” “color” and “material”). Amazon SimpleDB automatically indexes your data, making it easy to quickly find the information that you need. There is no need to pre-define a schema or change a schema if new data is added later.
Q: How do I interface with Amazon SimpleDB?
Amazon SimpleDB provides simple, standards-based REST and SOAP web services interfaces that are designed to work with any Internet-development toolkit. The operations are intentionally made simple to make it easy to add new service interfaces and for you to add custom functional layers over time.
Q: How secure is my data?
Amazon SimpleDB uses proven cryptographic methods to authenticate users. Your data is only available to you. If you would like extra security, you can encrypt your data before storing it in Amazon SimpleDB. If you choose to encrypt your data, you should remember that SimpleDB will query directly against the strings you store and will not do decoding for you.
Q: How reliable is Amazon SimpleDB?
The service runs within Amazon’s high-availability data centers to provide strong and consistent performance. To prevent data from being lost or becoming unavailable, your fully indexed data is stored redundantly across multiple servers and data centers.
Q: What happens if traffic from my application suddenly spikes?
Amazon SimpleDB was designed from the ground up to handle traffic for any Internet application. Pay-as-you-go pricing and unlimited capacity ensures that your incremental costs don’t change and that your service is not interrupted. Amazon SimpleDB’s scale enables us to spread load evenly, so that no individual application is affected by traffic spikes.
Q: I’m not in the US; can I use Amazon SimpleDB?
Anyone can use Amazon SimpleDB.

↑ Top

©2009, Amazon Web Services LLC or its affiliates. All rights reserved.