Migrate your SQL Server Workloads to PostgreSQL - Third Edition

I wrote the first edition of this book in 2020, after several years moving production workloads off SQL Server. The second edition, in 2022, updated that guidance as PostgreSQL matured. This third edition is a ground-up rewrite, not an update, because two things changed enough since 2022 to justify starting over: PostgreSQL shipped four major releases that closed real gaps (native temporal constraints, cheaper vacuuming, async I/O, built-in OAuth), and the shape of a migration project itself changed, serverless Postgres turned provisioning into a five-second decision, and LLM-assisted tooling turned schema and code conversion into a supervised, semi-automated process.

The book is restructured around how a migration actually unfolds: understand both platforms, assess what you have, choose a target, execute the move in stages, run it well once you're there, and validate that you landed where you meant to. It follows one migration end to end, three databases moving from SQL Server to PostgreSQL, covering schema conversion, data movement and validation, translating T-SQL to PL/pgSQL, security, monitoring, high availability, performance, and the validation and rollback planning that comes after cutover.

Almost every migration I've been involved in went sideways at least once, in some small, recoverable way, and rarely for the reason anyone predicted going in. This edition keeps that texture rather than the sanitized version where every conversion goes cleanly, with short field notes drawn from real migrations throughout. It's written for database administrators, platform engineers, and architects deciding whether, or how, to move relational workloads from SQL Server to PostgreSQL. Working knowledge of SQL Server is assumed; prior PostgreSQL experience is not.