G'day Jim,
I haven't looked at the article again, you could be right but I'd be surprised. My tables had no deleted records.

>Hi David,
>
>No one has yet mentioned the famous FPA article of May 1999 (pg 34) titled "Rushmore: Less Is More".
>
>It looks to me like your example fits the bill and so the problem would be the index on Deleted() (*assuming* that you are running with DELETED ON).
>
>Cheers,
>
>Jim N
>
>>Hi Albert,
>>I'm not using "UNION ALL" just "UNION" so they should be equivalent.
>>
>>>David has the explanation of the performance difference, but are you aware that the two selects are not equivalent? The select with the union will give two rows whenever (C.Addrnum = A.Addrnum AND C.PAddrnum = A.Addrnum).