Postgres with Builtin File Systems

2026-03-1421:147721db9.ai

Create, manage, and query serverless PostgreSQL databases from your terminal. Branching, migrations, observability, type generation — all built in.

Branch everything

One command creates an isolated copy — data, files, cron jobs, and user permissions. Test against real conditions, then delete it.

terminal

$ db9 branch create myapp --name staging
 Branch 'staging' created from database myapp.
 Name staging
 State ready
 Admin User admin

Tables & rows Files & uploads Cron jobs User permissions Extensions


Read the original article

Comments

  • By jacques_chester 2026-03-150:242 reply

    > db9 is a PostgreSQL-compatible distributed SQL database. Your data is stored in a distributed TiKV cluster, and each database (tenant) gets its own isolated keyspace. [0]

    I feel like the lede is a bit buried here, bordering on deceptive.

    That or the architecture doc is wrong. Both plausible I guess, in this day and age.

    [0] https://db9.ai/docs/sql

    • By c4pt0r 2026-03-150:322 reply

      Hello, the developer of db9 here. You’re right, that section is indeed a bit too brief. We will add more architecture documentation later. What I wanted to convey is that, unlike a standard PostgreSQL, db9 is more like a pg SQL-compatible layer built on top of a large distributed KV store. I also shared a brief introduction in this tweet, which might help clarify things. https://x.com/dxhuang/status/2032016443114733744

      • By jacques_chester 2026-03-154:17

        "Compatible" isn't mentioned on the homepage, though, despite multiple opportunities to do so -- "Create, manage and query serverless PostgreSQL", "Run history, status, and metadata live in Postgres", "Full Postgres. Fully typed.".

        This lack of detail may cause folks to form the incorrect impression that this is PostgreSQL, or a fork of it, or some module or plugin for it. Folks will be upset to learn that they were misinformed. Some will assign deception as the cause, whether that is true or not.

        I think your interests would be best served by trying to make that distinction clear and prominently so. So for example "A PostgreSQL-compatible, fully serverless database", or similar.

        I hope I have explained better.

      • By esafak 2026-03-151:122 reply

        If you're using TiKV why not use TiDB too, which is MySQL compatible?

        • By c4pt0r 2026-03-158:501 reply

          it has nothing to do with TiDB, db9 is built from scratch.A good way to think about it is that db9 is similar to tidb-server, it provides a PostgreSQL wire protocol and SQL layer, while the actual data lives in the underlying KV layer.

          • By esafak 2026-03-1512:37

            If it is based on TiKV, why is it built from scratch when TiDB exists? To achieve faster boot times? I think the bigger offering here is distributed-, not serverless Postgres!

        • By nullpoint420 2026-03-151:48

          Wonder if that’s what it is, with a few changes to make it postgres wire compatible

    • By TheTaytay 2026-03-153:371 reply

      Doltgres actually is a true versioned Postgres under the hood (or MySql).

      This sounds really interesting, and I like the ease with which I could spin something up here and get embeddings for sure! But I would think the actual runtime perf of this would be “fine” for some text, but nowhere near Postgres level for all sorts of other stuff, right?

      I am a huge fan of Postgres as a database, and of SQL, etc. but I don’t think I understand the benefit of using Postgres’ wire format here since it’s not Postgres behind the scenes. I guess that lets you use psql as the client?

      • By DetroitThrow 2026-03-158:34

        PG compatible means if you built your application or analytics queries for PG SQL, it's very easy to migrate to XYZ database that takes PG SQL as input and returns the same results in most cases. The wire format means you can point your code at the database and get the same responses as normal SQL.

        I agree with the commentary above that it's much clearer to describe something as "PG SQL/wire format compatible".

  • By anorak27 2026-03-155:311 reply

    You can do the same and a bit more with sqlite through agentfs

    https://github.com/tursodatabase/agentfs

    • By snthpy 2026-03-158:07

      This is really interesting! Thanks

  • By hintymad 2026-03-150:362 reply

    I think what’s really interesting is that the first version of db9.ai is done by a single person by commanding AI. There must be tons of invaluable lessons learned.

    • By gfygfy 2026-03-151:17

      AI is an instant turnoff and should be banned from HN. Unfortunately it is artificially promoted because of @sama despite not only providing no value but also making the world worse.

    • By c4pt0r 2026-03-150:52

      yes, it’s quite a journey

HackerNews