SQL Query to Find tuples with maximum number of identical values

Any ideas how to implement the query:

You are given a relation with N columns of the same type. Write an SQL2 query that returns the tuples having the maximum number of开发者_Python百科 identical values. The query should have size polynomial in N.

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yo u better hope prof. chomicki doesn't see this considering you used for real name and at @Alex you were right http://www.cse.buffalo.edu/~chomicki/462/p1.pdf