NestJS · Senior · Question 39 of 75

Why must DataLoader instances be created per request in a Nest GraphQL app?

1DataLoader can be created only once per process
2Per-request loaders are slower but required by GraphQL
✓Correct answer: DataLoader caches results; sharing it across requests leaks data between users and serves stale values

Explanation

Create loaders in the GraphQL context factory or a request-scoped provider.

Further reading

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