Richard Yen
Senior Software Engineer @ Microsoft
Richard Yen is a Senior Software Engineer at Microsoft with over 20 years of hands‑on experience operating PostgreSQL in production environments. He has worked across support, SRE, and engineering roles, helping organizations design, run, and recover large‑scale PostgreSQL systems.
Richard’s work focuses on reliability, observability, and disaster recovery—bridging the gap between PostgreSQL internals and real‑world operational practices. He is a frequent contributor to the PostgreSQL community through talks and writing, sharing lessons learned from incidents, outages, and long‑running production systems.
POSETTE 2026 Talk
pg_stats: How Postgres Internal Stats Work
Why does Postgres sometimes choose a Sequential Scan over an Index Scan, even when it seems slower? The answer almost always lies in the statistics. The query planner relies on a mathematical model of your data distribution to make decisions, and when that model is wrong, performance suffers.
In this session, we will crack open the pg_stats view to understand exactly how Postgres "sees" your data. We will cover histograms, most common values (MCV), and correlation. We will also explore Extended Statistics, a powerful feature for fixing bad query plans on correlated columns (like City and State), ensuring your planner stops guessing and starts knowing.
Add livestream to calendar Register for updatesPast Talks
-
Scaling the Wall of Text: Logging Best Practices in PostgreSQL (POSETTE 2024)
Subscribe to the POSETTE newsletter
to keep up with the latest news
Join the conversation
Use the hashtag #PosetteConf