R: Checking if a set of variables forms a unique index

Question

I have a large dataframe and I want to check whether the values a set of (factor) variables uniquely identifies each row of the data or not.

My current strategy is t

Answer 1

Perhaps anyDuplicated:

anyDuplicated( dfTemp[, c("Var1", "Var2", "Var3") ] )

or using dplyr:

dfTemp %.% select(Var1, Var2, Var3) %.% anyDuplicated()

This is still going to be wasteful though because anyDuplicated will first paste the columns into a character vector.