MTAR T3D Sessions: Adding Schema Change Events to PostgreSQL Logical Replication

PostgreSQL logical replication can provide a selective stream of data changes, but what happens when the schema itself changes?

James Nelson, Founder and CTO of PgCache, shares his Postgres wishlist: more information about DDL and schema changes in the logical replication stream. For systems that use replication events to keep a cache current, a dropped table can create a serious blind spot when there is no corresponding event to invalidate its cached data.

James and JD explore why consuming the binary replication stream is not always a practical alternative, including the volume of cluster-wide data and potential security concerns. They also consider possible workarounds using custom messages and triggers, and what a lightweight, opt-in approach could make possible for PostgreSQL extensions.