CREATE TABLE domain_keyword (did INT, kid INT)
CREATE TABLE domain (did INT, name VARCHAR)
CREATE TABLE publication (abstract VARCHAR, cid INT, citation_num INT, jid INT, pid INT, reference_num INT, title VARCHAR, year INT)
CREATE TABLE journal (homepage VARCHAR, jid INT, name VARCHAR)
CREATE TABLE author (aid INT, homepage VARCHAR, name VARCHAR, oid INT)
CREATE TABLE domain_conference (cid INT, did INT)
CREATE TABLE domain_journal (did INT, jid INT)
CREATE TABLE publication_keyword (kid INT, pid INT)
CREATE TABLE writes (aid INT, pid INT)
CREATE TABLE keyword (keyword VARCHAR, kid INT)
CREATE TABLE conference (cid INT, homepage VARCHAR, name VARCHAR)
CREATE TABLE domain_publication (did INT, pid INT)
CREATE TABLE domain_author (aid INT, did INT)
CREATE TABLE cite (cited INT, citing INT)
CREATE TABLE organization (continent VARCHAR, homepage VARCHAR, name VARCHAR, oid INT)

return me the conference that has the most number of papers containing keyword ' Relational Database ' .
SELECT conference.name FROM conference, keyword, publication, publication_keyword WHERE keyword.keyword = 'Relational Database' AND publication_keyword.kid = keyword.kid AND publication.cid = conference.cid AND publication.pid = publication_keyword.pid GROUP BY conference.name ORDER BY COUNT(DISTINCT (publication.title)) DESC LIMIT 1
SELECT "conference"."name" FROM "conference" JOIN "publication" ON "conference"."cid" = "publication"."cid" JOIN "publication_keyword" ON "publication"."pid" = "publication_keyword"."pid" JOIN "keyword" ON "keyword"."keyword" = 'Relational Database' AND "keyword"."kid" = "publication_keyword"."kid" GROUP BY "conference"."name" ORDER BY COUNT(DISTINCT "publication"."title") DESC NULLS LAST LIMIT 1