pgroll VS atlas

My thoughts exactly. It's surprising that external online schema change tools for Postgres have only become a thing fairly recently! The only two I'm aware of are:

* pgroll: Written in Golang, first commits June 2023. https://github.com/xataio/pgroll

* pg-osc: Written in Ruby, first commits Dec 2021. https://github.com/shayonj/pg-osc

Meanwhile over in the MySQL and MariaDB ecosystem, external OSC tools have been around for quite some time, starting with oak-online-alter-table over 15 years ago. The most popular options today are pt-online-schema-change or gh-ost, but other battle-tested solutions include fb-osc, LHM, and the latest entry Spirit.

I thought I recognized xataio - they submitted pgroll a few months back https://news.ycombinator.com/item?id=37752366 (https://github.com/xataio/pgroll - Apache 2)

At the start of October we released pgroll, an open source tool for zero-downtime, reversible schema migrations for Postgres.

If you have any suggestions or questions, please open an issue in our GitHub repo, reach out to us on Discord or follow us on X / Twitter. We'd love to hear from you and keep you up to date with the latest progress on pgroll.

Any pgroll operations[0] that require a change to an existing column, such as adding a constraint, will create a new copy of the column and backfill it using 'up' SQL defined in the migration and apply the change to that new column.

There are no operations that will modify the data of an existing column in-place, as this would violate the invariant that the old schema must remain usable alongside the new one.

[0] - https://github.com/xataio/pgroll/tree/main/docs#operations-r...

This is a fantastic article! It shows that even simple migrations (like adding or removing a column) can be quite tricky to deploy in concert with the application deployement.

We (at Xata) have tried for a while to come up with a generic schema migration system for PostgreSQL that makes this easier. We ended up using views and temporary columns in such a way that we can provide both the "old" and the "new" schema simultaneously. Up/down triggers convert newly inserted data from old to new and the other way around. This also has the advantage the it can do rollbacks instantly by just dropping the "new" view.

We were just planning to announce this as an open source project this week, but actually it is already public, so if you are curious: https://github.com/xataio/pgroll

Check out: https://github.com/ariga/atlas

(I'm one of the authors of this project).

fwiw, I personally am interested in this approach too[0]. I keep running into roadblocks around the ordering of events and some of the hairy issues around "destructive" actions (eg: renaming columns). i think we can get there, especially once we make progress with this LSP.

There are other notable mentions in this space:

Reshape: https://fabianlindfors.se/blog/schema-migrations-in-postgres...

Atlas: https://atlasgo.io/

[0] https://github.com/kiwicopple/declarative-schemas

Atlas: https://github.com/ariga/atlas. It can be integrated with any ORM, but also has an official one for GORM: https://atlasgo.io/guides/orms/gorm

Run the queryx db:create command to create a PostgreSQL database, and then run queryx db:migrate to automatically create the database migration files and database structure. Queryx’s database schema management is built upon Atlas.

One of https://atlasgo.io's creators here.

In this case, I'd recommend you to check Atlas: https://github.com/ariga/atlas

My name is Rotem, I'm one of the creators of Atlas (https://atlasgo.io) a modern open-source schema management tool. Recently one of our engineers created a cool Django plugin that creates beautiful (in my eyes at least ;-)) and shareable ERDs from your Django data models.

Yes, there is: Atlas! https://atlasgo.io / https://github.com/ariga/atlas.

Hi there You should take a look at Atlas - https://atlasgo.io which can help your team in many aspects of CI/ CD for databases : * CI - detect (and prevent) risky / incorrect migrations automatically * CD - support for modern deployment infrastructure (terraform, helm, etc)

You might want to check out Atlas. It provides automatic migration planning for GORM, and has various guides on how deploying schema migration on the popular platform and tools, such as Helm, Kubernetes and ECS.