Yesterday (2013-04-04) Kimberly Tripp & Paul Randal gave a great presentation at the Microsoft offices next to Radio City Music Hall in New York City.
Kimberly said: "Don't index all columns automatically in a WHERE clause."
I advise: "Index all columns in WHERE clause predicates."
My reasoning is that the caused damage is much greater by a missing index than the damage caused by an unnecessary index. Also since not all the forum readers are indexing experts, it helps that the rule is simple and easy to remember.
Naturally if you are indexing expert, you can be more selective.
Kalman Toth Database & OLAP Architect
sqlusa.com
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