David Johnston wrote > > JORGE MALDONADO wrote >> I have a table as follows: >> ------------------------------------------------ >> Table Artist Colaborations >> ------------------------------------------------ >> * car_id (integer field, primary key) >> * car_song (integer field, foreign key, foreign table is a catalog of >> songs) >> * car_artist (integer field, foreign key, foreign table is a catalog of >> artists) >> >> So, I added 2 indexes to improve JOIN in queries: >> 1. An index for car_song which accepts duplicates. >> 2. An index for car_artist which accepts duplicates. >> >> Now, the combination of "car_song + car_artist" cannot be duplicated so I >> think that adding a constraint on these 2 fields is the solution. >> >> My question: Is this the correct way to go? >> >> Respectfully, >> Jorge Maldonado > Yes. Why is it this is a question for you? > > Also, the car_id field becomes pointless since your new constraint is the > true and natural PK. > > David J.
with index only scans it seems that defining a pair of unique indexes (and no single column indexes) would have value. How much value I do not know. Would still want to drop the artificial id field. David J. -- View this message in context: http://postgresql.1045698.n5.nabble.com/Question-about-index-constraint-definition-in-a-table-tp5773924p5773942.html Sent from the PostgreSQL - sql mailing list archive at Nabble.com. -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
