Re: Optimization via explicit JOINs

On Fri, 9 Mar 2001, Stephan Szabo wrote:

-> Hmm, what were the two queries anyway?

The "slower" query
----------------------------
SELECT to_char( p.insertion_time, 'HH:MI AM MM/DD' ) as time_in, s.name                as title, a.name
asartist, s.length              as length
 
FROM playlist p, songs    s, artists  a
WHERE p.waiting   = TRUE          AND p.song_id   = s.song_id     AND s.artist_id = a.artist_id
ORDER BY p.item_id

The "faster" query
----------------------------
SELECT to_char( p.insertion_time, 'HH:MI AM MM/DD' ) as time_in, s.name                as title, s.length
aslength, a.name                as artist
 
FROM playlist p JOIN songs s USING (song_id), artists  a
WHERE p.waiting   = TRUE          AND p.song_id   = s.song_id     AND s.artist_id = a.artist_id
ORDER BY p.item_id;

Notice how the only difference is in the FROM clause?
-- Dave