18 Mutations & Subscriptions questions from the GraphQL bank, written for Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd.
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A.the root operation used to create, update or delete data, expected to cause server-side side effects
B.the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
C.the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
D.a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
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2. Which term means: "the root operation used to create, update or delete data, expected to cause server-side side effects"?
Junior
A.Subscription transport
B.Subscription operation
C.Mutation operation
D.Serial execution
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3. Which statement is correct?
Junior
A.Mutation operation — a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
B.Mutation operation — the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
C.Mutation operation — the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
D.Mutation operation — the root operation used to create, update or delete data, expected to cause server-side side effects
Answer + AI explanation with Pro
4. What is Serial execution?
Mid
A.the root operation used to create, update or delete data, expected to cause server-side side effects
B.a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
C.the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
D.the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
Answer + AI explanation with Pro
5. Which term means: "the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions"?
Mid
A.Subscription transport
B.Optimistic response
C.Subscription operation
D.Serial execution
Answer + AI explanation with Pro
6. Which statement is correct?
Mid
A.Serial execution — a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
B.Serial execution — a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
C.Serial execution — the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
D.Serial execution — the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
Answer + AI explanation with Pro
7. What is Subscription operation?
Junior
A.the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
B.the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
C.the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
D.a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
Answer + AI explanation with Pro
8. Which term means: "the root operation that opens a long-lived stream pushing real-time updates to the client as events occur"?
Junior
A.Optimistic response
B.Mutation payload type
C.Subscription operation
D.Mutation operation
Answer + AI explanation with Pro
9. Which statement is correct?
Junior
A.Subscription operation — a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
B.Subscription operation — the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
C.Subscription operation — the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
D.Subscription operation — a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
Answer + AI explanation with Pro
10. What is Subscription transport?
Mid
A.the root operation used to create, update or delete data, expected to cause server-side side effects
B.the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
C.a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
D.the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
Answer + AI explanation with Pro
11. Which term means: "the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers"?
Mid
A.Serial execution
B.Subscription operation
C.Subscription transport
D.Mutation operation
Answer + AI explanation with Pro
12. Which statement is correct?
Mid
A.Subscription transport — the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
B.Subscription transport — the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
C.Subscription transport — a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
D.Subscription transport — the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
Answer + AI explanation with Pro
13. What is Mutation payload type?
Senior
A.the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
B.the root operation used to create, update or delete data, expected to cause server-side side effects
C.a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
D.a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
Answer + AI explanation with Pro
14. Which term means: "a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result"?
Senior
A.Optimistic response
B.Subscription transport
C.Mutation payload type
D.Subscription operation
Answer + AI explanation with Pro
15. Which statement is correct?
Senior
A.Mutation payload type — a dedicated return object wrapping the affected entity plus metadata so a write can request fields on its result
B.Mutation payload type — the root operation used to create, update or delete data, expected to cause server-side side effects
C.Mutation payload type — the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
D.Mutation payload type — the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
Answer + AI explanation with Pro
16. What is Optimistic response?
Mid
A.the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
B.a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
C.the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
D.the persistent connection, typically WebSockets via graphql-ws, that carries pushed event payloads to subscribers
Answer + AI explanation with Pro
17. Which term means: "a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled"?
Mid
A.Subscription transport
B.Mutation operation
C.Serial execution
D.Optimistic response
Answer + AI explanation with Pro
18. Which statement is correct?
Mid
A.Optimistic response — a client-predicted result applied to the cache immediately before the server confirms a write, then reconciled
B.Optimistic response — the root operation used to create, update or delete data, expected to cause server-side side effects
C.Optimistic response — the guarantee that top-level write fields run one after another in order rather than in parallel, preventing race conditions
D.Optimistic response — the root operation that opens a long-lived stream pushing real-time updates to the client as events occur
Answer + AI explanation with Pro
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