CODEWITHSUNDEEP
amazon-dynamodbdynamodb-queriesamazon-dynamodb-index
danilobraga
danilobraga

Reputation: 165

In DynamoDB, which is faster? Querying by Id or by a secondary index attribute?

I have a DynamoDB table where I need to query on two different attributes, sometimes by one, sometimes by the other one, but never by both at the same time.

Let's say I have an attribute A and attribute B, other attributes are irrelevant here.

I'm thinking of design this table with the Hash Key being the attribute A and a GSI being attribute B. This way I always perform query instead of scan.

Now a question comes to my mind, which query is faster, on Attribute A (which is the Id) or on the Attribute B (GSI)?

If there is some difference I could switch, letting B as Id and A as GSI.

Thanks

Upvotes: 3

Views: 1891

Answers (1)

Horatiu Jeflea
Horatiu Jeflea

Reputation: 7404

The GSI is an actual DynamoDB table with all the main table data copied.

It can be more efficient if you project only the attributes you need.

It may be less efficient considering hash keys are not unique and you may end up iterating on those results to find the desired one.

Upvotes: 1

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