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" <[EMAIL PROTECTED]> 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 > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] >
