Databases
Intermediate
What is EXPLAIN ANALYZE?
A PostgreSQL command that shows the execution plan of a query along with actual runtime statistics for performance tuning.
EXPLAIN ANALYZE runs a query and shows how the database executed it: which indexes were used, join methods, row estimates vs actuals, and timing. This is the primary tool for query performance optimization.
Key things to look for: sequential scans on large tables (may need indexes), large differences between estimated and actual rows (statistics may be outdated), and nested loop joins on large datasets (may need different join strategy).
