Two key enhancements were announced on February 24, 2010 to SimpleDB: Consistent Read for
getAttributes/Select and Conditional Put/Delete.
Consistent Read enables you to get the most recent values bypassing the eventual consistency system. Consistent Read should not be used as a way to bypass eventual consistency, but is very useful in counters and code where reading the most recent value is critical.
In the following PHP sample, we create an item with the date/time and immediately use a
ConsistentRead=true, then a normal
getAttributes. The Consistent Read will return the just-updated value while the eventual consistency ...