Question

What is the most efficient way to detect duplicates in a 10 column / 50K row table? I’m using MSSQL 8.0

Answer 1

To show an example of what others have been describing:

SELECT     Col1, -- All of the columns you want to dedupe on     Col2, -- which is not neccesarily all of the columns     Col3, -- in the table     Col4,     Col5,     Col6,     Col7,     Col8,     Col9,     Col10 FROM     MyTable GROUP BY     Col1,     Col2,     Col3,     Col4,     Col5,     Col6,     Col7,     Col8,     Col9,     Col10 HAVING     COUNT(*) > 1