title: How to compare two S3 objects by content "server-side"
body: <p>Let's say I have any 2 objects stored in Amazon S3 in the same bucket (as the input of the task). I need to compare them by content. Not only that their length and checksum is the same but literally that the objects are identical byte after byte. The only way how I can do it now is reading the objects' data into my app on EC2 and comparing them. That, however, is not very time efficient and as well costs money for the data transfer.
  Is there a more efficient way of doing this? Could I do it somehow using a server-side code on S3 (some sort of lambda or similar) that would do that comparison without downloading the data to the EC2?</p>