Michael Austin wrote:
> and doesn't he really want f.FileKey = ua.FileKey (as you stated),
> so, isn't this backwards?
>
> "LEFT JOIN ProjFiles f ON ua.FileKey=f.FileKey"
>
> this, to me, says look at all records in f first, then match with ua.
> and since there is no where-clause for f, it does a FTS. Order really
> does matter.

Have you tried an experiment to prove this statement?
The order of operands around the equals statement should not matter. The
JOIN condition is what is stating that one should take all the records in ua
and lookup the equivalent row in f.
if the optimiser is sensitive to a=5 vs 5=a then it needs serious looking
at.