What causes SQL queries to slow down in production?

Missing indexes, full table scans, unoptimized WHERE clauses—especially on big tables without dev/prod parity.

How do you check SQL query plans?

Use EXPLAIN ANALYZE in Postgres/MySQL; look for Seq Scan vs Index Scan, high costs.

Dev/staging data is too small; real prod volume reveals the monsters hiding in plain sight.

☁️ Cloud & Databases

One line of SQL. $47,000 gone. Here's the production horror story that screams 'check your damn indexes.'

theAIcatchup Apr 09, 2026 3 min read

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Community-driven. Code-first.

#Postgres performance #SQL performance #SQL query optimization #database checklist #database-indexing #missing index #production outage #production outages #query optimization #query plans

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Originally reported by Reddit r/programming