To optimize performance, prevent components from re-rendering when they don’t need to react to query updates. **Rule:** If you use `useQuery`/`useFocusEffect` for *prefetching* or *side effects* and intentionally *ignore the result*, disable change notifications so the hook doesn’t subscribe to updates that would trigger re-renders. ### Apply to React Query prefetching (ignore result) When you “prefetch by calling `useQuery` but not using `data`”, you still create an observer and can cause re-renders. Pass an empty `notifyOnChangeProps` to avoid notifications. ```tsx function Article({ id }: { id: string }) { // Critical data used by UI const { data: articleData, isPending } = useQuery({ queryKey: ['article', id], queryFn: getArticleById, }) // Prefetch-only: prevent re-renders useQuery({ queryKey: ['article-comments', id], queryFn: getArticleCommentsById, notifyOnChangeProps: [], }) if (isPending) return 'Loading article...' return } ``` ### Apply to React Navigation focus If screen UI should not update while out of focus, gate notifications so query-driven state won’t re-render off-screen. In practice, implement a focus-aware `notifyOnChangeProps` (optionally using `navigation.isFocused()` if available) so that updates are suppressed while unfocused and re-enabled when focused again.