Postgres Is

4 min readFeb 17, 2025

Update: In response to a trademark notice from the PostgreSQL Community Association of Canada, domain has been changed from “Postgres.Is” to pgscorecard.com

When Amazon unveiled DSQL, social media buzzed with viral discussions about its touted PostgreSQL compatibility.

Some even joked that if DSQL truly is PostgreSQL compatible, why Larry Ellison has not proclaimed Oracle to be the world’s most PostgreSQL-compatible enterprise database?

Larry quoting Genghis Khan or otherway round?

Everyone claiming they are Postgres, Circa 103-BC (colorized)

This notion lingered in my mind when I encountered Gunnar (the former lead at Debezium) and Tudor (CTO of Xata) in a discussion about standardizing what it truly means to be PostgreSQL-compatible. Inspired by their exchange, I went on to create the Postgres Compatibility Index.

Postgres Compatibility Index (PCI)

PCI runs a battery of tests on the database in question, poking at every feature Postgres has to offer.
Each feature is scored, depending on whether it works, or implodes spectacularly.
The results are weighted, calculated, and distilled into a single PCI score, a percentage of compatibility perfection.

•The code for the PostgreSQL Compatibility Index (PCI) is freely available under the MIT License, because the journey to compatibility should be a collaborative effort.

•Feel free to explore the repository and send a PR to help enhance PCI for the entire Postgres community:
PostgreSQL Compatibility Index on GitHub

Next Level : postgres.is

Web app is built upon the dynamic JSON output produced by running pci_autotest.py

You can compare various attributes of different postgres derivatives.

You can see how postgres derivates fare for a specific attribute.

If you want your favorite postgres derivative to feature on website then just run pci_autotest.py and send me json output generated or if you are cloud provider then give me your free tier account. :-) .

POSTGRES IS

While the Postgres Compatibility Index meticulously addresses the technical facets of PostgreSQL, it also prompts a deeper, philosophical inquiry: What does it truly mean to be PostgreSQL? To explore this question, I draw upon Philip K. Dick’s “Human Is” as a metaphor, reflecting on the evolution of PostgreSQL over three transformative decades. Following series of memes eloquently conveys what a thousand words alone could not capture.