# Remove duplicates from training set for classification

Let us say I have a bunch of rows for a classification problem:

$$X_1, ... X_N, Y$$

Where $X_1, ..., X_N$ are the features/predictors and $Y$ is the class the row’s feature combination belongs to.

Many feature combination and their classes are repeated in the dataset, which I am using to fit a classifier. I am just wondering if it is acceptable to remove duplicates (I basically perform a group by X1 ... XN Y in SQL)? Thanks.

PS:

This is for a binary presence only dataset where the class priors are quite skewed

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