What Is Extension?
An extension is a package that adds features to PostgreSQL without modifying core code. Examples include PostGIS, pg_stat_statements, and hstore. They are installed using CREATE EXTENSION and can dramatically expand PostgreSQL capabilities.
Why It Matters for PostgreSQL Performance
In PostgreSQL performance work, Extension affects throughput, latency, or operational reliability depending on workload and configuration.
Practical Benchmarking Context
When benchmarking with pgbench, track how Extension 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
Install: CREATE EXTENSION IF NOT EXISTS pg_stat_statements;