20 Apr 2024

Unlock PostgreSQL Superpowers with pg_tle

pg_tle - A Must-Know for Developers

PostgreSQL is a fantastic database, packed with features. But sometimes, you need to add a little something extra – a custom function, a specialized data type, or maybe a procedure written in your favorite programming language. That's traditionally where PostgreSQL extensions come in. But for developers working with managed databases (from major cloud providers), while installing supported extensions is trivial installing custom or unsupported extensions can be tricky or even impossible.

Enter pg_tle!

What exactly is pg_tle?

pg_tle stands for Trusted Language Extensions. Here's the breakdown:

  • Extension: A piece of software that adds new functionality to PostgreSQL.
  • Trusted Language: A programming language (like JavaScript, Perl, or PL/pgSQL) that the database 'trusts' due to security restrictions built into the language itself.
  • The Magic: pg_tle provides a framework to build, package, and install extensions in these trusted languages, even in environments where you can't normally touch the underlying server.

Why is pg_tle Important for Application Developers?

  1. Unlock New Possibilities: pg_tle lets you create custom database functions tailored to your application's unique logic. Say you need complex data validation or even specialized calculations – pg_tle can make it happen.

  2. Bypass Restrictions: On managed database services, you often can't install traditional extensions. pg_tle works within these constraints allowing you to add functionality even in these environments - See Use Cases below for more.

  3. Enhanced Security: Because pg_tle uses trusted languages, your extensions have limits on what they can do. It leads to a more secure database overall.

  4. Open Sourcepg_tle is open source [3] and available on Github (Apache 2.0 License).

Use Cases - Just A Sample Of Ideas

  • Use Unsupported Extensions: This itself is a reason big enough to try out pg_tle! [4]
  • Custom Password Strength Checks: Go beyond basic password rules with an extension.
  • Login Triggers: Build custom rules that get triggered for every time a user logs into the database - not just for (the upcoming) v17 but also for older PostgreSQL versions!
  • Custom Data-Types: Build custom data-types that you could use to store data, functions and views within your database.
  • Data Transformations: Perform complex data manipulations directly within the database.

The Trade-offs

  • Complexity: Creating pg_tle extensions can be more involved than basic SQL scripting.
  • Limitations: Trusted languages still have constraints compared to the full capability of extensions developed in lower-level languages (like C).

Should You Learn More?

If any of the following resonate with you, then deeper pg_tle knowledge could be a big win:

  • You crave more flexibility in how you work with data, and although have found an extension it's not yet natively supported in your PostgreSQL installation.
  • Your application has a few "extra tricky" calculations or data processing needs, that are much easily possible with Perl, Javascript, PL/PGSQL.
  • You work with managed databases and miss those power-user extensions.


pg_tle is a powerful tool that adds flexibility and extensibility for PostgreSQL developers. While a bit more advanced, understanding pg_tle unlocks a new level of database customization for your applications.

If you're intrigued, keep an eye out for a follow-up post where I'll show a simple example of building a pg_tle extension!


  1. Trusted Language Extensions for PostgreSQL on Amazon Aurora and Amazon RDS - https://aws.amazon.com/blogs/aws/new-trusted-language-extensions-for-postgresql-on-amazon-aurora-and-amazon-rds/
  2. Creating custom data-types using Trusted Language Extensions - https://aws.amazon.com/blogs/database/create-custom-postgresql-data-types-using-trusted-language-extensions/
  3. pg_tle is open source! - https://github.com/aws/pg_tle
  4. pg_tle makes using custom extensions easier - https://aws.amazon.com/blogs/opensource/supabase-makes-extensions-easier-for-developers-with-trusted-language-extensions-for-postgresql/
  5. Installing pg_tle on Ubuntu - https://www.thatguyfromdelhi.com/2024/04/installing-pgtle-on-ubuntu-quick-guide.html

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