Show HN: Pub/Sub with PostgreSQL under 40 lines of Python code | Hacker News Reader

Show HN: Pub/Sub with PostgreSQL under 40 lines of Python code

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17 pointskissgyorgy5 comments

It can be used as a more durable message queue too by following the recommendations in https://www.youtube.com/watch?v=B81nQLg4RuU

Nice. Reminds me of a time I was learning Rust. Did a small test to get Node.JS and Rust to "communicate" via Postgres[0]

I am curious if this is an approach folks actually use in production, though.

[0]: https://gist.github.com/zikani03/e4fa4f150940dbdb03a6761fd0c...

Interesting! I wonder if you could use this in a Django project with Channels, and stream database changes over websocket to the client. I think I've found a project for this weekend!

I must admit my DB knowledge is lacking. What is the purpose of setting the isolation level to autocommit?

    > I wonder if you could use this in a Django project with Channels, and stream database changes over websocket to the client.I wonder if you could use this in a Django project with Channels, and stream database changes over websocket to the client.

That's exactly what I'm doing with this! :) But you don't even need channels for that! The point is to simplify the stack.

    > What is the purpose of setting the isolation level to autocommit?

Notifications are only sent after a transaction has been committed, see: https://www.postgresql.org/docs/12/sql-listen.html

Here is an example in the psycopg2 documentation: https://www.psycopg.org/docs/advanced.html#asynchronous-noti...

Yes you can. I used this same technique a long time ago, for cache-invalidation.

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