Hi,

Why i am seeing additional attribute 'Sdb-item-identifier'?

Hello,

As Amazon Simple DB could not allow to sort data by Amazon Simple DB Item Identifier so we are proving additional Attribute that is copy of Amazon Simple DB Item Identifier, so that you can sort your data using Amazon Simple DB Item Identifier. Now Amazon Simple DB allow to Sort your data by Amazon Simple DB Item Identifier so you will not found this feature in our next release.

Thanks