Hi, Since user_id is a primary key. It should work either with any of the column and with both the column.
Any suggestion. Thanks On Thu, May 15, 2008 at 1:22 AM, Rob Wultsch <[EMAIL PROTECTED]> wrote: > On Tue, May 13, 2008 at 1:30 AM, Krishna Chandra Prajapati > <[EMAIL PROTECTED]> wrote: > > Hi all, > > > > Below is the user_delivery table structure. > > > > CREATE TABLE `user_delivery` ( > > `user_id` decimal(22,0) NOT NULL default '0', > > `delivery_id` decimal(22,0) NOT NULL default '0', > > `send_to_regulator` char(1) default NULL, > > PRIMARY KEY (`user_id`), > > KEY `user_delivery_comp1` (`user_id`,`delivery_id`), > > CONSTRAINT `fk_user_delivery` FOREIGN KEY (`user_id`) REFERENCES > > `user_info` (`user_id`) ON DELETE NO ACTION ON UPDATE NO ACTION > > ) ENGINE=InnoDB DEFAULT CHARSET=latin1; > > > > According to me user_delivery_comp1 index can be dropped and new index > can > > be created on delivery_id column. I would to know that the changes will > work > > or not. Yours suggestion regarding this table structure. > > > > Thanks, > > -- > > Krishna Chandra Prajapati > > > > Define work. > > The effect should be something like: > Queries that have where clauses for delivery_id but not user_id would > be able to use an index. > Queries that have where clauses for delivery_id and user_id might not > be able to use as much of an index. Depending on your version of mysql > merge index may apply, but I am not knowledge enough to comment of the > performance differences between the two. I would assume a composite > index when available would generally be more ideal. > > > -- > Rob Wultsch > [EMAIL PROTECTED] > wultsch (aim) > -- Krishna Chandra Prajapati MySQL DBA, Ed Ventures e-Learning Pvt.Ltd. 1-8-303/48/15, Sindhi Colony P.G.Road, Secunderabad. Pin Code: 500003 Office Number: 040-66489771 Mob: 9912924044 URL: ed-ventures-online.com Email-id: [EMAIL PROTECTED]
