sqldba_newbie (2/28/2013)
I was in an assumption that index would only change the execution plan and not the actual output of the data. I have a query which gives completely different results on two different indices?
Only if you have something in that query that assumes an order without having an order by specified. Essentially when you're assuming an order exists where there is none, an index (and a bunch of other things) can change that order resulting in different output (or different update results). Not the fault of the index, the result of assuming there's an order when there's no order by specified.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability