At 08:29 29/04/02 -0700, Jeremy Zawodny wrote: >On Mon, Apr 29, 2002 at 01:06:02PM +0100, David Hanney wrote: > > > I've got a nice fat varchar(255) primary key who's content is > > duplicated (as a foreign key) in many other tables. I hope MySQL > > optimizes away that duplication internally. > >Not as much as you're probably hoping for. Consider making an MX5() >hash of the string and using that instead. It'll buy you a lot of >space.
I could take some kind of hash. Better yet I could add an "id BIGINT NOT NULL auto_increment" column and use that for forming relationships (instead of using the "varchar(255)"). But there'd be a one-to-one mapping between the auto_increment and the varchar ... in information-terms it adds nothing. The auto_increment would only be there for implementation efficiency. This seems like a database task, not an application task. I don't want to do it in both places so that's why I'm curious as to what the database actually does. Any info appreciated! DH --------------------------------------------------------------------- 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
