>>What's the usability of calculating the max() of a character field in a lookup table, which is the same for all records in a group? This would do the same, just much faster.
>
>I have now seen your thoughts.
>
>If you known that on the group the expression is constant, then
>min=max=any and these are equals:
>

>SELECT item,MIN(exp)  FROM test GROUP BY item
>SELECT item,MAX(exp)  FROM test GROUP BY item
>SELECT item,exp       FROM test GROUP BY item,exp
>SELECT item,exp       FROM test GROUP BY exp,item
>
>set engine 70
>SELECT item,exp FROM test GROUP BY item
>

>
>This is a very special case,
>and a lot of times it conceals a bad planning of the database;
>then it is difficult to justify the implementation of ANY()
>
>Besides, the most powerful databaseses (MSSQL,..) succeed in optimizing
>the standard description (with the subquery)
>and they implement of fact a function FIRST().

So if it works that way behind the scenes, there's no overhead? Good to know.