CREATE TABLE ARTIST (Name VARCHAR2, ArtistId VARCHAR2)
CREATE TABLE ALBUM (ArtistId VARCHAR2)

Which artist has the most albums?
SELECT T2.Name FROM ALBUM AS T1 JOIN ARTIST AS T2 ON T1.ArtistId = T2.ArtistId GROUP BY T2.Name ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."Name" FROM "ALBUM" "T1" JOIN "ARTIST" "T2" ON "T1"."ArtistId" = "T2"."ArtistId" GROUP BY "T2"."Name" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY