pgroll (via) “Zero-downtime, reversible, schema migrations for Postgres”
I love this kind of thing. This one is has a really interesting design: you define your schema modifications (adding/dropping columns, creating tables etc) using a JSON DSL, then apply them using a Go binary.
When you apply a migration the tool first creates a brand new PostgreSQL schema (effectively a whole new database) which imitates your new schema design using PostgreSQL views. You can then point your applications that have been upgraded to the new schema at it, using the PostgreSQL search_path setting.
Old applications can continue talking to the previous schema design, giving you an opportunity to roll out a zero-downtime deployment of the new code.
Once your application has upgraded and the physical rows in the database have been transformed to the new schema you can run a --continue command to make the final destructive changes and drop the mechanism that simulates both schema designs at once.
Recent articles
- Claude can write complete Datasette plugins now - 8th October 2025
- Vibe engineering - 7th October 2025
- OpenAI DevDay 2025 live blog - 6th October 2025