Hacker News Reader

Comment by netghost | Hacker News Reader

If you're not using meteor, but are interested in using this in node, take a look at the library it's built on: https://github.com/numtel/pg-live-select

At a glance it looks like it creates triggers on the fly and tears them down. I'm curious how scaleable this is, is trigger creation a locking activity in postgres?

View on HN

Creating views and triggers on the fly does sound like insanity. There's got to be a better way.

There is: logical decoding http://www.postgresql.org/docs/9.4/static/logicaldecoding.ht... I wonder why the author chose to waste time on this instead of doing things the proper way.

See this issue: https://github.com/numtel/pg-live-select/issues/1

I would love to see a pull request for the "proper way." Thank you for your help.

Logical decoding was only recently added in Postgres (9.4)? I'm not sure on the privileges required for logical decoding in postgres, but typically it requires 'root' access because it lets you see all the data in the system. So triggers can often be used on a shared database, where you might not be allowed to access the transaction log.

I'd guess ignorance? I'd never heard of 'logical decoding' before and the name of the feature doesn't lend itself to easy understanding.

That said, thanks for pointing this out - it looks like yet another very useful PG feature!

At times it feels as if the entire Nosql industry was created by people not reading the Postgresql manual.

edit: thanks for the link to logical decoding, looks very useful.

Create triggers, fire all events off to a proper message broker for fanout.

Events can be triggered directly in PG using an extension for AMQP or something, or in a standalone service, using whatever you can dream up.

Reply on news.ycombinator.com