Install pgloader with Homebrew, apk, apt, Nix, zypper

Project links

• Homepage
• Package manager page

Commands and aliases

• pgloader

Project history

Dimitri Fontaine originally implemented pgloader in Python and later rewrote it in Common Lisp. The rewrite enabled a richer command language, runtime-compiled transformations, and higher performance.

The 3.x series established the SQL-like `.load` command syntax and direct database-to-PostgreSQL migration workflow. Official documentation now also describes a v4 Clojure/JVM rewrite while retaining the command-file model.

Adoption history

pgloader is packaged by Homebrew, Debian, Ubuntu, Alpine Linux, Nix, and openSUSE according to source_facts.package-manager. That breadth reflects its established role in PostgreSQL migration workflows.

Its one-command migrations from SQLite, MySQL, Microsoft SQL Server, and structured files have made it a common bridge for teams moving workloads into PostgreSQL.

How it is used

Simple migrations can be expressed as `pgloader SOURCE TARGET`; more complex jobs use explicitly supplied `.load` command files. These files can define sources, targets, casts, transformations, PostgreSQL settings, and SQL to execute before or after loading.

Connection strings may contain database credentials, but the official documentation does not designate a separate credentials file. Load-command files are user-selected inputs rather than a configuration file at a fixed filesystem location.

Why package nerds care

pgloader is notable for combining database discovery, type casting, transformation, error handling, and PostgreSQL COPY streaming in one tool. It is also an unusual systems utility whose established implementation is written in Common Lisp after an earlier Python implementation.

For package maintainers, pgloader is interesting because its database drivers and Common Lisp build chain historically made packaging more involved than distributing an ordinary script, while delivering a native executable and substantial migration functionality.

Timeline

• Early project: pgloader began as a Python program.
• Later rewrite: The project moved from Python to Common Lisp.
• 3.x era: The SQL-like load-command language and direct database migration workflow became the established interface.
• Current development: Official documentation describes a Clojure/JVM v4 rewrite alongside the Common Lisp implementation.

Related projects

• pgloader relies on PostgreSQL's COPY protocol for high-throughput loading and complements PostgreSQL tools such as `psql` and `createdb`. It targets migration use cases that otherwise require combinations of database dump tools, ETL scripts, and manual schema conversion.

Sources

• Official documentation: https://pgloader.readthedocs.io/en/latest/
• Official project article on the Python-to-Common-Lisp rewrite: https://pgloader.io/blog/pgloader-your-migration-companion/
• Official quick start: https://pgloader.readthedocs.io/en/latest/quickstart.html
• source_facts.package-manager