Database: academic
Question: return me the keyword, which have been contained by the most number of papers by " H. V. Jagadish " .
SQL: select t1.keyword 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 t2.name  =  "h. v. jagadish" group by t1.keyword order by count ( distinct t3.title ) desc limit 1;