Blog
schemachange runs ordered migration scripts with no diff and no rollback. SDT declares desired state, computes the delta, and classifies every change for safety — with a one-command importer.
Liquibase orders changesets; SDT declares desired state and computes the delta — with a 4-tier safety classifier that reasons per change and refuses data loss.
SQLMesh manages transformation models with virtual environments and column lineage. SDT/DDT deploy the full DDL surface with a 4-tier safety classifier. They coexist — here's the boundary.
Application code has CI gates, blue-green deploys, and rollback. Your warehouse schema has a Slack channel. Why the gap persists — and what state-based schema management with a safety classifier fixes.
A Snowflake stream stores an offset, not rows — and three innocent-looking DDL changes destroy it with no recovery path. What a stream really is, why Time Travel will not save you, and the checklist that prevents it.
On Databricks, CREATE OR REPLACE TABLE is the recommended rebuild — which is what makes it dangerous. Where the Delta safety net ends, what is genuinely unrecoverable, and how to review for it.