Re: WIP patch for parallel pg_dump

Andrew Dunstan <andrew@dunslane.net> writes:
> Why not just say give me the snapshot currently held by process nnnn?

There's not a unique snapshot held by a particular process.  Also, we
don't want to expend the overhead to fully publish every snapshot.
I think it's really necessary that the "sending" process take some
deliberate action to publish a snapshot.

> And please, not temp files if possible.

Barring the cleanup issue, I don't see why not.  This is a relatively
low-usage feature, I think, so I wouldn't be much in favor of dedicating
shmem to it even if the space requirement were predictable.
        regards, tom lane