Database: aan_1
Question: Count the number of papers published by Columbia University in 2009.
SQL:
SELECT count(DISTINCT T1.paper_id) FROM Paper AS T1 JOIN Author_list AS T2 ON T1.paper_id  =  T2.paper_id JOIN Affiliation AS T3 ON T2.affiliation_id  =  T3.affiliation_id WHERE T3.name LIKE "Columbia University" AND T1.year  =  2009