Janardhan <jana-reddy@mediaring.com.sg> writes:
> if i am not wrong while updating a tuple, we are also creating a new
> index entry .
Yes.
> so if the
> tuple is dead then the index entry pointing it also a dead index tuple.
Yes.
> so even if dead index tuple is not
> removed then also it should not break thing, since the dead index tuple
> will not be used, am i correct?.
No. A process running an indexscan will assume that the index tuple
accurately describes the heap tuple it is pointing at. If the heap
tuple is live then it will be returned as satisfying the indexscan.
regards, tom lane