def get_chromosomes(self, sv=False):
        """Return a list of all chromosomes found in database
        
        Args:
            sv(bool): if sv variants should be choosen
        
        Returns:
            res(iterable(str)): An iterable with all chromosomes in the database
        """
        if sv:
            res = self.db.structural_variant.distinct('chrom')
        else:
            res = self.db.variant.distinct('chrom')
            
        return res