Veraticus/Dynamoid — pull request #91 by loganb (2012-12-17 23:14:39+00:00)
Title: Check for existence on creation rather than silently clobber

Hello,

I noticed that if two competing threads attempt to create objects concurrently with the same key, one will silently clobber the other since Dynamoid does an unconditional put on new records. This patch adds an unless_exists clause to the put_item request so that one will fail. This is more consistent with the behavior of ActiveRecord and avoids silent data corruption.