>>About when UNION ALL is slower than UNION kill me I don't know. My first answer is "NEVER" but I suspect that if there is such a question maybe there are occasions when that statements is true. Maybe for huge tables and proper indexes the filtering could be faster than just APPEND, but as I said I am not sure at all.
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>I also answered that UNION ALL is faster and also was puzzled where UNION ALL would be slower. The answer was when UNION would return a huge result set the UNION ALL might be slower, I never verified this, BTW.
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YEAH!!!!!!
Finally guessed correctly on a tech question I knew almost nothing about.