CODEWITHSUNDEEP
amazon-dynamodb
noamtm
noamtm

Reputation: 12983

DynamoDB query by non-partition fields

Given a DynamoDB table that looks similar to:

sessionId: String
deviceType: String (mobile/tablet/computer/...)
networkType: String (wifi/ethernet/3g/4g/...)

There may be some other fields. I need to be able to look up a session id given the other parameters. SQLish:

But from what I understand, querying in DynamoDB always requires the partition key (sessionId).

Is there an alternative layout to this table that will allow for better querying? We're still in setup phase, so it can be changed.

Upvotes: 0

Views: 41

Answers (1)

ben11
ben11

Reputation: 114

To be efficient and cost effective, I suggest you to create 2 Global Secondary Indexes (GSI). The PK will be "deviceType" and "networkType". For the SK and I don't have enough information to suggest something. Hence, no need to project all attributes because you only want to retrieve sessionId which is projected by defaut because it is a PK.

To sum up the data model:

         PK              Attributes
Table:   sessionId       deviceType, networkType, ...
GSI_1:   deviceType      sessionId, networkType, ...
GSI_2:   networkType     sessionId, deviceType, ...

For example, while querying GSI_1, you'll use PK="Mobile" for example to retrieve all related sessionId.

Doing this way is really fast and cost effective as the opposite as scan.

Upvotes: 1

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