CODEWITHSUNDEEP
nosqlamazon-dynamodb
Bruno Joaquim
Bruno Joaquim

Reputation: 1463

Dynamodb update attribute value among related items

As it says in Dynamodb documentation, it's recommended that we use only one table to model all our entities.

You should maintain as few tables as possible in a DynamoDB application. Most well-designed applications require only one table.

Now suppose that we have a product and a user entity, using only one table we have a schema like this:

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In dynamodb, its recommended that we keep related data together, that's why the user data is "duplicated" on the product entry.

My question is, if one day I update the user name, dynamodb will be able to update automatically the copy of that user on my product entry, or this kind of update has to be made manual?

Upvotes: 0

Views: 195

Answers (1)

user11677199
user11677199

Reputation: 139

In DynamoDB, it is recommended to keep the items in de-normalized form for achieving the benefits of DynamoDb. Having said that, while designing the table we keep the application layer design in mind based on which we try to fetch the results from the single table to get the values that can be used to create the single entity with all the mappings satisfied. Hence we create the table with columns that can hold the values from other related table. The only difference is we are just putting the relationship values for keeping the connection to other related tables.
In the above scenario, we can have user details in one table and while creating the table for product, keep the primary key of user table in the product table. So that, if the username or user detail is changed in future, there wouldn't be any problem. In DynamoDB, using sort key for the table, will keep the related items together. There is also a provision of composite sort keys to deal with one-many relation. Sharing the Best practices of using sort keys: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-sort-keys.html

Upvotes: 1

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