What Is Optimizer?
The PostgreSQL optimizer analyzes queries to choose the most efficient execution plan. It considers indexes, statistics, joins, and filters. Understanding the optimizer helps diagnose slow queries.
Why It Matters for PostgreSQL Performance
In PostgreSQL performance work, Optimizer affects throughput, latency, or operational reliability depending on workload and configuration.
Practical Benchmarking Context
When benchmarking with pgbench, track how Optimizer changes behavior across scale factor, client concurrency, and storage conditions.
Use this term together with workload shape, concurrency level, and scale factor when interpreting pgbench outputs. Isolated values can be misleading without full run context.
Example
Tool: EXPLAIN ANALYZE reveals the optimizer’s chosen plan.