When an SQL Database Makes a Great Pub/Sub
There’s a perspective that the transaction log of a typical RDBMS is the canonical form and the rows &amp; tables merely the event-sourced projection. After all, if you replay the former, you should always get exactly the same in the latter.<p>It’s curious that over those projections, we then build event stores for CQRS&#x2F;ES systems with their own projections mediated by application code.<p>Let’s also mention the journaled filesystem on which the database logs reside. And the log structure that your SSD is using internally to balance writes.<p>It’s been a long time since we wrote an application event stream linearly straight to media, and although I appreciate the separate concerns that each of these layers addresses, I’d probably struggle to justify them from first principles to even a slightly more Socratic version of myself.