>Hi,
>
>>
>I have done your test and it suggests that my *old* understanding is the correct one and Fabio's understanding is wrong! Agree?
>>
>
>Not really. As I mentioned it doesn't really prove anything. The fact that it doesn't appear to happen in a few thousand iterations doesn't mean that it will *never* happen. And if it *can* happen then any additonal lines between the 'SELECT' and the use of _tally would increase the risk.
>

Exactly.