Foreign Key + Index

Imagine 2 tables:
AUTHORS
author_id (int) (PK)
author_name (varchar)
BOOKS
book_id (int) (PK)
book_author_id (int) (FK from AUTHOR)
book_title (varchar)
book_author_id is already declared as a foreign key.
If I want better performance when querying SELECT * FROM BOOKS WHERE
book_author_id = 1234
do I have to set a index on book_author_id,
or is it unecessary as a FK is already set?
I think that as a FK is a constraint and not an index, it's still necessary
but I want to be sure.
Can you answer my question?
Thanks
Henria Foreign Key is NOT automatically indexed in SQL Server.
you'll need to index it.
Greg Jackson
Portland, OR|||Thanks for your answer Greg :-)
"pdxJaxon" <GregoryAJackson@.Hotmail.com> a écrit dans le message de
news:OMI0r%234EFHA.3200@.TK2MSFTNGP10.phx.gbl...
> a Foreign Key is NOT automatically indexed in SQL Server.
> you'll need to index it.
>
> Greg Jackson
> Portland, OR
>
>