Database: academic_minus_1_0
Question: return me the author who has the most number of papers containing keyword " Relational Database " .
SQL: select t4.name from publication_keyword_keyword as t1 join publication as t2 on t1.pid = t2.pid join writes as t3 on t2.pid = t3.pid join author as t4 on t3.aid = t4.aid where t1.keyword = 'relational database' group by t4.name order by count ( distinct t2.title ) desc limit 1 ;