How do I fix slow aggregation, pagination or N+1 queries?
Understand the concept
Query performance depends on how much data is scanned, joined, sorted and returned for each useful result. Slow pagination and N+1 patterns often do repeated work that grows with result size. The best fix usually reduces that work before increasing hardware or connection limits.
Important ideas
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Check scan counts and indexes; reduce documents before expensive joins or groups.
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For deep pages, use a stable cursor such as
createdAtplus_id. -
Batch related reads and reuse a bounded connection pool.
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Keep filters, selected fields and sort keys consistent with cursor construction, including a unique tie-breaker.
Can you explain it without the notes?
How do I fix slow aggregation, pagination or N+1 queries?
Use your own words. Explain an example and one limitation before checking the explanation.
Check your explanation
Query performance depends on how much data is scanned, joined, sorted and returned for each useful result. Slow pagination and N+1 patterns often do repeated work that grows with result size. The best fix usually reduces that work before increasing hardware or connection limits.
Turn this concept into a clear answer.
- Compare query count, examined documents and latency before and after the change, not just endpoint code length.
Adapted from 04_MONGODB_MONGOOSE.md · “How do I fix slow aggregation, pagination or N+1 queries?”. Examples are study fragments; framework behavior can depend on your version.