Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> I must confess that it strikes me as a really really horrid and ugly
> hack - very likely to be error-prone and non-portable and undebuggable,
> and for almost no saving worth having. But maybe that's just me.
No, that was exactly my reaction too. I'd be willing to buy into it
if we had a lot of lists that needed to be traversable in both
directions and we were concerned about the storage overhead for such
lists. But we don't, we aren't, and so I'm not ...
regards, tom lane