Career
Debugging Slow Queries in Production
Senior Data Analyst
April 7, 2026
6 min read
The Checklist
1. **Check active queries**: `pg_stat_activity`.
2. **Identify the slow query**: `pg_stat_statements` or logs.
3. **Run EXPLAIN ANALYZE**.
4. **Look for Seq Scans on large tables**.
5. **Check for missing indexes or table bloat**.
6. **Kill the query if necessary**: `SELECT pg_cancel_backend(pid);`
*Day 98: The Modern Data Stack and SQL's Role.*