Another little doubt:
I've already asked that in #postgresql at freenode, but I didn't
understand well.
I have two tables:
Books
- book_id
- name
Authors
- author_id
- name
One book can have many authors and one author can have many books. To
make that possible, I need a third table:
Intermediate
- book_id
- author_id
My question is about the indexes in Intermediate table. Is the
following index:
CREATE UNIQUE INDEX foo ON Intermediate(book_id, author_id);
enough for every query I want to perform? Or should I need
CREATE UNIQUE INDEX foo ON Intermediate(book_id, author_id);
CREATE UNIQUE INDEX bar ON Intermediate(book_id);
CREATE UNIQUE INDEX baz ON Intermediate(author_id);
too?
Thank you very much. Bye!
