Re: Temp rows - is it possible?

Boris Popov wrote:
> Hello Bruce,
>
> Monday, November 10, 2003, 11:08:47 AM, you wrote:
>
> BM> Tom Lane wrote:
> >> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> >> > Tom Lane wrote:
> >> >> We recently decided we had to forbid foreign-key references from temp
> >> >> tables to permanent tables because of this effect.  I wonder whether
> >> >> we won't end up forbidding temp tables as children of permanent tables
> >> >> too.
> >>
> >> > Yep, I think we will have to do that.  TODO item?
> >>
> >> Plan B would be to arrange for the planner to ignore temp tables of
> >> other backends whenever it is searching for child tables.  Then the
> >> behavior would be predictable: you never see any rows inserted in other
> >> people's temp child tables (and cannot update or delete 'em, either).
> >> I'm not sure if this is the behavior the OP wanted, but it seems at
> >> least marginally useful.
>
> BM> Agreed.  It seems wrong that a session should ever see other people's
> BM> temp tables as children.
>
> So going back to the original problem, do you think there should be a
> way to implement temp rows in tables visible to everyone? I worked
> around the original problem I had by using custom entries in
> pg_listener (listen "identifier") and that works well because they
> disappear as soon as backend detects the disconnect, but I'd really
> like to be able to do exact same thing outside of pg_listener and be
> able to reference that table from other permanent tables, which is
> currently impossible with pg_listener as its a part of system catalog.

We have basically coupled "rows only exist during your session" and
"rows only visible to your session".  I don't see much demand in
decoupling that, and I don't know a good way to do in application code
either.  Sorry.

In your requested setup, once your session exists, all the session rows
disappear for everyone --- that seems to be a strange application
requirement.


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