Does Your GROUP BY Order Matter?
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Sometimes when you do GROUP BY, the order of the columns does matter. For example, these two SELECT queries produce different results: Transact-SQL CREATE INDEX Location_DisplayName ON dbo.Users(Location, DisplayName); SELECT TOP 100 Location, DisplayName, COUNT(*) AS Duplicates FROM dbo.Users GROUP BY Location, DisplayName ORDER BY Location, DisplayName; SELECT TOP 100 DisplayName, Location, COUNT(*) AS Duplicates…
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