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DDD: how to handle large collections

I am currently developing a backend for a social networking app in REST. I am very intrigued by the DDD principle. Now suppose I have a User object that has a collection of friends. It can be thousands if the application and the user become very successful. Each friend also has some properties, it is mainly a user. Looking at the DDD Cargo application example , a fully expanded Cargo object is stored and retrieved from CargoRepository from time to time. WOW, if there is a list in the placeholder, over time this will call OOM eventually. That's why there is a paginated dot and lazy loading if you approach the problem in terms of data. But how could you handle these large collections in a non-persistent DDD persistence?

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As pointed out in the comments of @JefClaes: you need to determine if your UserAR really requires a collection Friends.

Ownership does not necessarily mean that a fee is required.

Take the example of Order/ OrderLine. OrderLinedoesn't make sense without being a part Order. However Customer, to which a belongs Order, does not have a set of Orders. It may possibly have a collection ActiveOrdersif the customer is limited by the maximum number (or number) of active orders. Saving a collection of historical orders would be unnecessary.

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