Hello,
The documentation often mentions that foreign key support in mysql is not implemented because it slows down the database server. The argument is that since the applications built on top of mysql have to check for database integrity constraints (ICs) it is redundant for the database to perform these checks as well. However it would be very convenient to have a setting in /etc/my.cnf for enabling/disabling the checking of foreign keys with the default being off in the interest of speed. The reason a user would want this is that if there is a lot of data in an existing database then the application developer does not want the application to mess up the data due while the application is not yet stable. Thus, in such a scenario, foreign keys are helpful. Thus in addition to a setting in /etc/my.cnf it would be helpful to have commands such as "ENABLE FOREIGN KEYS" and "DISABLE FOREIGN KEYS" allowing more flexibility on multiuser systems. The same mechanism could be use to enable/disable CHECK constraints including CHECK constraints involvins SELECT statements. These could always be enforced/not enforced with commands such as "ENABLE CHECK IC" and "DISABLE CHECK IC" or something similar, with the default set to DISABLED in the intrest of speed, but with the syntax in the table data definition language (DDL) still being parsed and accepted in both cases, as for foreign keys. Thank you for mysql, Neil Zanella [EMAIL PROTECTED] --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
