Non-Blocking Schema Changes

This post details PlanetScale's non-blocking schema change workflow, which leverages Vitess and gh-ost. It introduces database branching as a method for creating isolated sandbox environments for testing schema changes. Deploy requests are used to manage schema changes, and a deploy queue ensures sequential deployment. The system analyzes schema changes for conflicts against the main branch and preceding deploy requests to prevent issues. The workflow aims to allow developers to push schema changes as easily as code changes.