Apollo quiz

Test your Apollo knowledge with a free interactive quiz — 20 questions with answers and explanations. No signup needed to play.

What is the "N+1 query problem" in GraphQL server implementations (including those built with Apollo Server), and how does a tool like DataLoader typically address it?

1. What is the "N+1 query problem" in GraphQL server implementations (including those built with Apollo Server), and how does a tool like DataLoader typically address it?
2. What is the purpose of the `useMutation` hook in Apollo Client, and how does it typically differ from `useQuery`?
3. What is a "resolver" in the context of Apollo Server (and GraphQL generally)?
4. What is Apollo Client's "local state management" capability (via `@client` directive fields or reactive variables), and what problem does it solve alongside remote GraphQL data?
5. What is the purpose of the `refetchQueries` option on an Apollo Client mutation?
6. What is the purpose of Apollo's schema-first (or "SDL," Schema Definition Language) approach to defining a GraphQL API's types?
7. What does "polling" (via Apollo Client's `pollInterval` option on `useQuery`) provide as an alternative to GraphQL subscriptions for keeping data relatively fresh?
8. What is Apollo (Apollo Client/Apollo Server), in the context of GraphQL development?
9. What is Apollo Client's "fetch policy" (like `cache-first`, `network-only`, or `cache-and-network`), and what does it control?
10. What is "optimistic UI" (via Apollo Client's `optimisticResponse` option on a mutation), and what user-experience problem does it address?
11. What is "cache normalization" combined with a mutation's ability to automatically update the cache — what does Apollo Client's `update` function (or automatic cache updates based on returned mutation data) accomplish?
12. What is a reasonable general criterion for deciding whether GraphQL/Apollo is a better fit for a project than a traditional REST API, versus situations where REST might remain the simpler, more appropriate choice?

More quizzes