CREATE TABLE torrents (groupname CLOB, totalsnatched NUMBER, artist CLOB, groupyear NUMBER, releasetype CLOB, groupid NUMBER, id NUMBER)
CREATE TABLE tags (index NUMBER, id NUMBER, tag CLOB)

Whose CDs sells best?
SELECT artist FROM torrents GROUP BY artist ORDER BY SUM(totalsnatched) DESC LIMIT 1
SELECT "artist" FROM "torrents" GROUP BY "artist" ORDER BY SUM("totalsnatched") DESC FETCH FIRST 1 ROWS ONLY