pgroll

What pgroll is

pgroll is an open-source command-line tool for PostgreSQL schema migrations that lets old and new schema versions remain available while client applications move between them. Its expand/contract workflow is intended to keep applications running during changes; the project describes migrations as zero-downtime and says they do not lock the database. Applications select a schema version by setting PostgreSQL's search_path when connecting. pgroll can backfill columns automatically and roll an active migration back to the previous schema version. For breaking changes, it creates virtual schemas from views over physical tables and uses triggers to carry writes between old and new columns. It supports PostgreSQL 14 and later, including RDS and Aurora, and ORM-generated SQL can be converted, with examples for Alembic, Django, and Drizzle. Generated migrations may still require manual up and down data migrations and consolidation of SQL statements. On PostgreSQL 14, versioned views do not respect row-level security policies, making pgroll a likely poor fit when using RLS on that version. It is licensed under Apache License 2.0.