Node.js · Middle · Question 46 of 75

Why do Node.js apps use a database connection pool?

1A pool lets one query run on several databases
✓Correct answer: Opening a connection is slow; a pool reuses a limited number of open connections across requests
3Databases require exactly one connection per request

Explanation

Size the pool for the database's limits. Always release a checked-out client, even on errors, or the pool runs dry and requests hang.

Further reading

node-postgres: Pooling ↗

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