Re: notification payloads

Hannu Krosing <hannu@skype.net> writes:
> Ühel kenal päeval, T, 2007-03-27 kell 07:11, kirjutas Andrew Dunstan:
>> Er, what listen table? 

> At least the list of which backends listen to which events should be
> also in shared mem.

No, the intent is specifically that there will be *no* such global
structure.  All it does is add complexity, not to mention make it
harder to size shared memory.

> How else would we know how many copies to make for each backend or when
> we can release the memory in case we make one copy ?

The proposed design is essentially a clone of the sinval messaging
system, which does not need to know either of those and does not make
"one copy per backend".  There's one copy, period.
        regards, tom lane