Re: newbie questions about composite key

[Peter Brawley]

Why keep date & time in different columns?

If there is zero possibility of two reports arriving with timestamps within one sec of each other, you can use a timestamp column (resolution=1 sec) as a PK (it's trivial to extract day, hour, min & sec from such a column). Otherwise merely keep an index on the timestamp, and mount a PK which delivers zero possibility of duplication, ie an auto_increment (surrogate) PK. I think you will find that such a query will greatly simplify many of your queries.

PB