/* DBLP #1 */
SELECT DISTINCT a2.author_name
FROM authors as a1,
     writes as w1,
	 authors as a2,
	 writes as w2
WHERE a1.author_name = 'Christopher Olston'
  AND a1.author_id = w1.author_id
  AND w1.paper_id = w2.paper_id
  AND w2.author_id = a2.author_id
  AND a1.author_id != a2.author_id;

/* DBLP #2 */
SELECT DISTINCT p.paper_title
FROM authors as a1,
     writes as w1,
	 papers as p,
	 authors as a2,
	 writes as w2
WHERE a1.author_affiliation = 'Carnegie Mellon University'
  AND a1.author_id = w1.author_id
  AND w1.paper_id = p.paper_id
  AND p.paper_id = w2.paper_id
  AND w2.author_id = a2.author_id
  AND a2.author_affiliation = 'Carnegie Mellon University'
  AND a1.author_id != a2.author_id;

/* DOODLE #1 */
SELECT DISTINCT p.url
FROM pages as p,
     words as w1,
	 contains as c1,
	 words as w2,
	 contains as c2
WHERE w1.word = 'superbowl'
  AND c1.word_id = w1.word_id
  AND c1.page_id = p.page_id
  AND w2.word = '2006'
  AND c2.word_id = w2.word_id
  AND c2.page_id = p.page_id;


/* DOODLE #2 */
SELECT DISTINCT p.url
FROM pages as p,
     words as w1,
	 contains as c1,
	 words as w2,
	 contains as c2,
	 sites as s,
	 belongs as b
WHERE w1.word = 'george'
  AND c1.word_id = w1.word_id
  AND c1.page_id = p.page_id
  AND w2.word = 'bush'
  AND c2.word_id = w2.word_id
  AND c2.page_id = p.page_id
  AND s.name = 'www.cnn.com'
  AND s.site_id = b.site_id
  AND b.page_id = p.page_id;

/* DOODLE #3 */
SELECT DISTINCT p.url
FROM pages as p,
     words as w1,
	 contains as c1,
	 words as w2,
	 contains as c2
WHERE w1.word = 'brad'
  AND c1.word_id = w1.word_id
  AND c1.page_id = p.page_id
  AND w2.word = 'pitt'
  AND c2.word_id = w2.word_id
  AND c2.page_id = p.page_id
  AND c1.pos = c2.pos - 1;

/* DOODLE #4 */
SELECT DISTINCT s1.name
FROM sites as s1,
     pages as p1,
	 belongs as b1,
	 sites as s2,
	 pages as p2,
	 belongs as b2,
	 links as l
WHERE s2.name = 'www.cnn.com'
  AND s2.site_id = b2.site_id
  AND b2.page_id = p2.page_id
  AND s1.site_id = b1.site_id
  AND b1.page_id = p1.page_id
  AND p1.page_id = l.links_id
  AND p2.page_id = l.linked_id
  AND s2.site_id != s1.site_id;

/* DOODLE #5 */
SELECT DISTINCT s.name
FROM sites as s
WHERE s.site_id NOT IN (
        SELECT DISTINCT _s.site_id
        FROM   pages as p,
               belongs as b,
			   sites as _s
        WHERE p.page_id NOT IN (
				SELECT _p.page_id
				FROM   pages as _p,
                       pages as p2,
        	           belongs as b2,
        	           sites as s2,
        	           links as l
                WHERE p2.page_id = b2.page_id
        	      AND b2.site_id = s2.site_id
        	      AND s2.name = 'www.cnn.com'
        	      AND _p.page_id = l.links_id
        	      AND p2.page_id = l.linked_id
              )
          AND p.page_id = b.page_id
  	      AND b.site_id = _s.site_id
      )
  AND s.name != 'www.cnn.com';