⚡
Advanced About 30 min

EXPLAIN & Query Performance

Read query plans, spot sequential scans, add indexes, and turn slow queries into fast ones.

What you'll learn

  • Read EXPLAIN output to understand query execution plans
  • Distinguish Seq Scan, Index Scan, and Bitmap Scan
  • Use EXPLAIN ANALYZE to see actual execution times
  • Identify join strategies: Nested Loop, Hash Join, Merge Join
  • Compare query approaches to find the most efficient one