Dynamo db sorting

Question

I have a scenario in which I will have to list the incoming requests of a user sorted based on creation time and priority(High, Medium, Low) along with pagination. Is there a way to achieve this in dynamoDb ?

Right now I'm using a secondary Index like userId-createdAt-index which sorts data based on creation time and further sorting the request based on priority separately in the frontend. Somebody please provide a right solution for this.

Answer 1

You're correct to use an index with a sort key. This could also be your primary index, thus reducing how many indexes you need, but that of course depends on whether you already have a sort key on your primary.

DDB guarantees the order of a sorted index, so paging will correctly page by date for you, if you want to reverse the order, add the ScanIndexForward to your query and set it to false.

Your model of query / sort by date at the DB level, then sort by other fields at the application level is normal and correct.

Depending very much on your use-case, another option to consider is querying by priority by using KeyConditions and adding the condition #priority EQ :priority, but I doubt this is what you want.