option to handle or filter out blank strings for the sink

[dollschasingmen]

I know this is an issue due to DynamoDb but it would be really convenient if the connect had an option to simply remove attributes that are blank strings. Currently we are handling this issue (kind of poorly) upstream in the kafka stream stage.

I feel like this is kind of an odd quirk of DynamoDb that I don't really see in many other data stores and would be nice if the connect shielded this annoying detail from the rest of the systems.

[dollschasingmen]

a similar idea to: aws/aws-sdk-js#833

[shikhar]

Interesting, I think this could also potentially be handled with a single-message-transform (KIP-66).

But happy to implement in this connector since it seems like DynamoDb specifically does not allow empty string values. Feel free to submit a PR even if it's just basic filtering of such attribute values, or I can get to it.

[shikhar]

Additionally it appears empty sets are not allowed: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Limits.html