What Is HOT Update?
A HOT (Heap-Only Tuple) update modifies a row without changing indexed columns. PostgreSQL skips index rewrites, reducing bloat and speeding up updates. It's automatic if indexes aren't affected.
Why It Matters for PostgreSQL Performance
In PostgreSQL performance work, HOT Update affects throughput, latency, or operational reliability depending on workload and configuration.
Practical Benchmarking Context
When benchmarking with pgbench, track how HOT Update 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
Check: pg_stat_user_tables for HOT update stats.