MTAR T3D Sessions: RDS Lowers the Barrier—Not the Risk

More than a refresh: Conversations with the most interesting people you've never met · Feb 10, 2026 · 10m

In this episode, JD sits down with Brian Fehrle to unpack a deceptively simple PostgreSQL operation that can trigger serious performance issues: adding a new column with a default value.

Brian explains how PostgreSQL’s optimization—introduced to avoid table rewrites and long locks—can leave data “virtual” rather than physically written to disk. While this makes schema changes faster, it can quietly confuse the query planner, skew statistics, and turn previously fast queries into production problems, especially when the new column is used in WHERE clauses.

This episode is a must-listen for…