Finding (and Fixing) a Silent Throughput Ceiling in PostgreSQL

“A benchmarking case study on relation extension locks, partitioning, and peak write load”; I gave this talk at PG Pune 2026, a community Postgres event with about 170 attendees, mostly database engineers, DBAs and Postgres enthusiasts. This post is the written version, plus two questions from the audience. Under heavy write load, I ran into a throughput saturation in Postgres.