Re: proposal: make NOTIFY list de-duplication optional

On Sat, 6 Feb 2016 at 12:50 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> > I agree with what Merlin said about this:
> >
> http://www.postgresql.org/message-id/CAHyXU0yoHe8Qc=yC10AHU1nFiA1tbHsg+35Ds-oEueUapo7t4g@mail.gmail.com
>
> Yeah, I agree that a GUC for this is quite unappetizing.
>

How would you feel about a variant for calling NOTIFY?

The SQL syntax could be something like "NOTIFY [ALL] channel, payload"
where the ALL means "just send the notification already, nobody cares
whether there's an identical one in the queue".

Likewise we could introduce a three-argument form of pg_notify(text, text,
bool) where the final argument is whether you are interested in removing
duplicates.

Optimising the remove-duplicates path is still probably a worthwhile
endeavour, but if the user really doesn't care at all about duplication, it
seems silly to force them to pay any performance price for a behaviour they
didn't want, no?

Cheers,
BJ