AWS SimpleDB - less dense drives

Question

In the FAQs of AWS SimpleDb service I have noticed paragraph

Q: When should I use Amazon S3 vs. Amazon SimpleDB?

Amazon S3 stores raw data. Amazon SimpleDB takes your data as input and indexes all the attributes, enabling 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.

Can somebody explain how AWS SimpleDB reach high data access speed with using of less dense drives?

As I know: more density -> more speed.

Answer 1

You can read these posts that may help you.

Check out:

1. SimpleDB Essentials for High Performance Users: Part 1
2. SimpleDB Essentials for High Performance Users: Part 2
3. SimpleDB Essentials for High Performance Users: Part 3
4. SimpleDB Performance : 5 Steps to Achieving High Write Throughput

Answer 2

Amazon SimpleDB is a non-relational (NoSQL) data store. These days, if you're looking to use NoSQL on AWS, DynamoDB is recommended. SimpleDB is not even listed on the service menu.

It can reach high speeds because it is a database (with item-level data pre-loaded and indexed), while Amazon S3 is an object store (that only works at the object level).