seniorMongoDB

How do you optimize slow queries in MongoDB?

Updated May 1, 2026

Short answer

Optimization involves analyzing the 'Explain Plan' and ensuring proper indexing.

Deep explanation

Use .explain('executionStats') to find 'COLLSCAN' stages. Ensure the Winning Plan uses an index. Avoid $or where $in can be used, and ensure the 'Equality, Sort, Range' (ESR) rule is followed for compound indexes.

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