Querying DynamoDB by date

Question

I'm coming from a relational database background and trying to work with amazon's DynamoDB

I have a table with a hash key "DataID" and a range "CreatedAt" and a bunch of items in it.

I'm trying to get all the items that were created after a specific date and sorted by date. Which is pretty straightforward in a relational database.

In DynamoDB the closest thing i could find is a query and using the range key greater than filter. The only issue is that to perform a query i need a hash key which defeats the purpose.

So what am I doing wrong? Is my table schema wrong, shouldn't the hash key be unique? or is there another way to query?

Answer 1

Approach I followed to solve this problem is by created a Global Secondary Index as below. Not sure if this is the best approach but hopefully if it is useful to someone.

Hash Key                 | Range Key
------------------------------------
Date value of CreatedAt  | CreatedAt

Limitation imposed on the HTTP API user to specify the number of days to retrieve data, defaulted to 24 hr.

This way, I can always specify the HashKey as Current date's day and RangeKey can use > and < operators while retrieving. This way the data is also spread across multiple shards.