I'm using the python framework Boto to interact with AWS DynamoDB. But when I use "item_count" it returns the wrong value. What's the best way to retrieve the number of items in a table? I know it would be possible using the Scan operation, but this is very expensive on resources and can take a long time if the table is quiet large.
The item_count value is only updated every six hours or so.  So, I think boto is returning you the value as it is returned by the service but that value is probably not up to date.
Boto's DynamoDB API returns wrong value when using item_count