> Tuples with an aborted xmin can be vacuumed right away. When we're
> following the update chain in EvalPlanQual, it's possible that the updater
> has aborted, the updated dead tuple is vacuumed away, and the slot is
> reused for another unrelated tuple.
But if the updater aborted, how can EvalPlanQual be called?
In this situation (updater aborted), EvalPlanQual's caller (such as
ExecUpdate and ExecDelete)
should get "HeapTupleMayBeUpdated", rather than "HeapTupleUpdated".
Am I right?
