Databases · Senior · Question 31 of 75

A query is fast in development but slow in production with the same indexes. What should you check first?

1The ORM version
✓Correct answer: The production plan with EXPLAIN (ANALYZE, BUFFERS): data volume and distribution, statistics and cache state differ
3The client's network speed

Explanation

With 100 rows every plan is fast. Skewed data (one tenant with millions of rows) can make a plan good for most values and terrible for a few.

Further reading

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