I am not certain that Foreign Keys (FKs) are even considered when
evaluating a SELECT statement. I know that the indexes that the FKs point
to in either table play a major role in determining the execution plan but
I don't think that the FKs actually participate in SELECT queries.
Now, does having those tables so well-indexed play a role in improving
query performance? Probably, but you should use the EXPLAIN command to
find out for sure:
http://dev.mysql.com/doc/mysql/en/EXPLAIN.html
Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine
"Ulrich Seppi" <seppi@stripped> wrote on 10/13/2004 11:33:09 AM:
> Hello people,
> does anybody know if Foreign keys increase the performance of select
querys?
> example.
> DB1 has only INNODB tables.
> DB2 has the same structure as DB1 with all possible foreign keys.
>
> is the same query faster on DB1 or DB2?
> regards
> Uli
>
>
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