maximum field and item size limits in dynamo db and mongo db

Question

I want to use dynamo DB to store some attributes which are big string values...

Is there any maximum field size/maximum item size limitation in Dynamo DB? Something which limits the data that i store for 1 item in a table?

Also, what is the equivalent limit (if any) in Mongo DB?

I am evaluating these 2 nosql databases as possible solutions for one of my applications. Any advice/inputs you could give would be appreciated.

Answer 1

The MongoDB limit is currently 16MB per document, this has increased a couple of times over the course of development, but that is the limit as of the current release (2.0.x at the time of writing), see here:

http://www.mongodb.org/display/DOCS/Documents

I'm not as familiar with the various limits in Dynamo, but you can find a list of them here:

http://docs.amazonwebservices.com/amazondynamodb/latest/developerguide/Limits.html

Answer 2

DynamoDB max per item is currently 64k (which is seen by many as a serious shortcoming). Best practice for documents larger than 64k would be to store a pointer to document (S3?) instead of the entire document, but this obviously has some associated issues as well.

Answer 3

The maximum size allowed for an item in Dynamo DB is 400KB. This is mentioned here