"Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
> AFAIC the relation between objects is not copied correctly
> by copyObject() (i.e the same pointers to an object are copied
> to different pointers by copyObject()).
True, but it seems irrelevant to me --- as Jan Wieck was just pointing
out, no code should ever depend on pointer-equality in parse trees or
plan trees anyway.
> There is a way to maintain the list of (old,new) pairs during
> copyObject() operations.
I think we'd be better off fixing any places that mistakenly assume
pointer compare is sufficient. You didn't say which version you were
testing, but we know there are a few bugs like that in the current
CVS sources because of collateral damage from the EXCEPT/INTERSECT
patch. I believe the plan is to either fix them or back out the patch
before 6.5.
regards, tom lane