text: # Find variants on chromosome 17 that reside on the same position with the same reference base
  SELECT
    contig,
    position,
    reference_bases,
    COUNT(position) AS num_alternates
  FROM
    [google.com:biggene:1000genomes.variants1kG]
  WHERE
    contig = '17'
  GROUP BY
    contig,
    position,
    reference_bases
  HAVING
    num_alternates > 1
  ORDER BY
    contig,
    position,
    reference_bases;