<p>Based on their work, how do you distinguish a great SQL developer?  </p>

<p>Examples might include:</p>

<p>Seldom uses CURSORs, and tries to refactor them away.<br>
Seldom uses temporary tables, and tries to refactor them away.<br>
Handles NULL values in OUTER JOINs with confidence.<br>
Avoids SQL extensions that are not widely implemented.
Knows how to indent with elegance.</p>

I don't think that cursors, temporary tables or other SQL practices are inherently bad or that their usage is a clear sign of how good a database programmer is.
I think there is the right tool for every type of problem. Sure, if you only have a hammer, everything looks like a nail. I think a great SQL programmer or database developer is a person who knows which tool is the right one in a specific situation. IMHO you can't generalize excluding specific patterns.
But a rule of thumb may be: a great database developer will find a more
short and elegant solution
for complex situations than the average programmer.