Cetin,

own problem is not on the time when the SELECT start, but while the SELECT execute, DATETIME() change, and this change is usefull to you.

The process of call DATETIME() is random for the first call, but all next call are correlate with this first event;
for remove this, is need that the execution process have a white spectre.

For get 5 randomly picked customers, you need SELECT duration is more 5 seconds, and implement one randomization function RANDOM(DATETIME()).

The naturally function for do this task is RAND() function.

I need one exclusive example, that is one SELECT impossible to implement without the DATETIME() dinamically variations.

Fabio