This makes a really nice introduction to BigQuery (which is to say: BigQuery is nicely discoverable, given an easy-to-understand dataset).

Is there a good way to find the story to which a comment belongs? This dataset raises the issue of recursive query (e.g. "with recursive" in SQLite or PostgreSQL, or "connect by" in Oracle). The only approach I see in BigQuery is specifying a fixed level with something scary like:

  SELECT p0.text, s.id, s.title
  FROM
    [fh-bigquery:hackernews.comments] p0
  JOIN EACH [fh-bigquery:hackernews.comments] p1 ON p1.id=p0.parent
  JOIN EACH [fh-bigquery:hackernews.comments] p2 ON p2.id=p1.parent
  JOIN EACH [fh-bigquery:hackernews.comments] p3 ON p3.id=p2.parent
  JOIN EACH [fh-bigquery:hackernews.comments] p4 ON p4.id=p3.parent
  JOIN EACH [fh-bigquery:hackernews.stories] s ON s.id=p4.parent
  WHERE
    REGEXP_MATCH(p0.text, '(?i)bigquery')
  ORDER BY
    p0.time DESC

For this particular data set: linking each comment to its story might be a good denormalization.