Re: proposal: make NOTIFY list de-duplication optional

On Tue, Feb 9, 2016 at 2:16 PM, Filip Rembiałkowski
<filip(dot)rembialkowski(at)gmail(dot)com> wrote:
> But then it becomes disputable if SQL syntax change makes sense.
>
> ---we had this,
> NOTIFY channel [ , payload ]
> ---and in this patch we have this
> NOTIFY [ ALL | DISTINCT ] channel [ , payload ]
> --- but maybe we should have this?
> NOTIFY channel [ , payload [ , mode ] ]

I think using ALL to mean "don't worry about de-duplication" could be
a bit confusing, especially as there was some interest recently in
supporting wildcard notifications:
http://www.postgresql.org/message-id/52693FC5.7070507@gmail.com

and conceivably we might want to support a way to notify all
listeners, i.e. NOTIFY * as proposed in that thread. If we ever
supported wildcard notifies, ALL may be easily confused to mean "all
channel names".

What about adopting the options-inside-parentheses format, the way
EXPLAIN does nowadays, something like:

NOTIFY (DEDUPLICATE FALSE, MODE IMMEDIATE) mychannel;

Josh