Sqitch

Sqitch is an open‑source database change management tool designed to manage schema migrations across environments in a dependency‑driven, version‑controlled workflow. It aims to provide reproducible deployments without embedding version information inside the database itself, making migrations portable across development, testing, and production.

Core concepts and structure: A Sqitch project centers on a plan file that lists changes and their dependencies. Each change has three associated scripts: deploy, revert, and verify, stored under a project directory (for example, deploy/<change>.sql, revert/<change>.sql, verify/<change>.sql). The plan defines the order in which changes should be applied, based on explicit dependencies rather than implicit version numbers.

How it works: When deployed, Sqitch records which changes have been applied in the target database, enabling subsequent operations to apply only pending changes. Revert scripts allow rolling back changes in the reverse order, and verify scripts validate that a deployment behaves as expected. The plan can be tagged to mark milestones in the migration history.

Workflow and integration: Sqitch is designed to work with version control systems, commonly Git, so changes and their scripts travel with application code. Typical commands include adding a new change (sqitch add), deploying changes (sqitch deploy), reverting changes (sqitch revert), verifying deployments (sqitch verify), and tagging milestones (sqitch tag). The tool emphasizes collaboration, traceability, and reproducibility across teams.

Supported databases: Sqitch supports multiple relational databases through adapters, including PostgreSQL, SQLite, MySQL, and Oracle, among others. It is widely used in environments requiring cross‑database migrations and robust change history.

Overall, Sqitch provides a declarative, trackable approach to database migrations that complements modern development workflows and continuous deployment practices.