How to implement pagination when using amazon Dynamo DB in rails

Question

I want to use amazon Dynamo DB with rails.But I have not found a way to implement pagination.

I will use AWS::Record::HashModel as ORM.

This ORM supports limits like this:

People.limit(10).each {|person| ... }  

But I could not figured out how to implement following MySql query in Dynamo DB.

SELECT *    FROM  `People`   LIMIT 1 , 30 

Answer 1

You issue queries using LIMIT. If the subset returned does not contain the full table, a LastEvaluatedKey value is returned. You use this value as the ExclusiveStartKey in the next query. And so on...

From the DynamoDB Developer Guide.

Answer 2

You can provide 'page-size' in you query to set the result set size. The response of DynamoDB contains 'LastEvaluatedKey' which will indicate the last key as per the page size. If response does't contain 'LastEvaluatedKey' it means there are no results left to fetch. Use the 'LastEvaluatedKey' as 'ExclusiveStartKey' while fetching next time.

I hope this helps.

DynamoDB Pagination