Comment by javajosh
5 years ago
>LISTEN ties up a connection
Wait, what?? I can't keep doing things with my connection after I issue a LISTEN? That doesn't seem right! I would assume it would isomorphic to how unix-y bg programs will occasionally write to the console (although I see how this might be hard to deal with at the driver level). Now I will have to go check.
You (the application) can certainly go on to issue other database commands. See the docs [1].
> With the libpq library, the application issues LISTEN as an ordinary SQL command, and then must periodically call the function PQnotifies to find out whether any notification events have been received.
[1]: https://www.postgresql.org/docs/current/sql-listen.html