Hello
2013/4/20 JORGE MALDONADO <jorgemal1...@gmail.com> > Let´s suppose that I have a SELECT statement that joins more than one > table and such a statement is order by fields that belong not only to the > table in the FROM but also by fields in the tables that are part of the > JOIN´s. How does indexes should be considered in a case like this? For > example: > > SELECT artist_name, author_name, producer_name, song_name > FROM tbl_songs > INNER JOIN tbl_artists ON tbl_artists.artistid = tbl_songs_artistid > INNER JOIN tbl_authors ON tbl_authors.authorid = tbl_songs_authorid > INNER JOIN tbl_producers ON tbl_producers.producerid = tbl_songs_producerid > ORDER BY song_name > > It depends on size of relations - you don't need indexes on small tables - hash join will be used. For bigger tables indexes on PK (automatically) and FK are good idea. Regards Pavel > Respectfully, > Jorge Maldonado >
