Database: academic
Question: return me the author who has the most number of papers containing keyword " Relational Database " .
SQL:
SELECT t2.name FROM publication_keyword AS t5 JOIN keyword AS t1 ON t5.kid  =  t1.kid JOIN publication AS t3 ON t3.pid  =  t5.pid JOIN writes AS t4 ON t4.pid  =  t3.pid JOIN author AS t2 ON t4.aid  =  t2.aid WHERE t1.keyword  =  "Relational Database" GROUP BY t2.name ORDER BY COUNT ( DISTINCT t3.title ) DESC LIMIT 1;