DynamoDB Scan does not support segments

[stephen-christie-ss]

I am making a Lambda which splits a scan into multiple segments for "threaded" processing, and hoped to test the logic with Moto before trying it for real. It seems that Moto doesn't understand the concept, however.

AWS documentation:
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Scan.html#Scan.ParallelScan

Moto implementation:

moto/moto/dynamodb/responses.py

Line 833 in 12cd186

items, scanned_count, last_evaluated_key = self.dynamodb_backend.scan(

[bblommers]

Hi @stephen-christie-ss, welcome to Moto! Marking it as an enhancement to implement this feature.