CREATE TABLE broadcast (channel_id NUMBER, program_id NUMBER, time_of_day CLOB)
CREATE TABLE program (program_id NUMBER, name CLOB, origin CLOB, launch NUMBER, owner CLOB)
CREATE TABLE channel (channel_id NUMBER, name CLOB, owner CLOB, share_in_percent NUMBER, rating_in_percent NUMBER)
CREATE TABLE broadcast_share (channel_id NUMBER, program_id NUMBER, date CLOB, share_in_percent NUMBER)

Find the total rating ratio for each channel owner.
SELECT SUM(rating_in_percent), owner FROM channel GROUP BY owner
SELECT SUM("rating_in_percent"), "owner" FROM "channel" GROUP BY "owner"