Carsten Kropf <ckropf2(at)fh-hof(dot)de> writes:
> I have a question about the replacement of an item in an index page. I
> want to overwrite an existing item inside an index page.
Why exactly do you want to do that? How are you going to make it
transactionally correct or crash-safe?
FWIW, I think the ItemIdSetUnused call is wrong or at least unnecessary.
Perhaps it is confusing PageIndexTupleDelete.
regards, tom lane