[jlizzle30]

I've been thinking about prototyping a Firebase clone that uses a relational database and SQL syntax. Instead of subscribing to "nodes" you would subscribe to queries. Anyone know if this exists already?

[gary__]

Related in a limited fashion:

https://docs.microsoft.com/en-us/dotnet/framework/data/adone...

Then there's this write-up of someone replacing rethinkdb with postgres for live queries - (including a link to some code)

http://blog.sagemath.com/2017/02/09/rethinkdb-vs-postgres.ht...

Have you any plans already of how you will go about this?

[cjbprime]

How would you (as the DB author) know when a query has updated results?

[jlizzle30]

Something like this:

  subscribe ('SELECT * FROM tableA', callback)

On the initial subscription, 'callback' would be called once for each row in 'tableA', then again when a row is inserted or updated. It would be the same as Firebase in this respect.

[cjbprime]

No, you as the person writing this new database, not you as the user of the API.

[eat_veggies]

Not OP but I would watch for mutations in the subscribed columns, then test the changed rows on the query's constraints and fire an event if it satisfies them.

I'm sure there is a more clever/efficient way of doing this though, and I can't wait to see how he/she implements it.