On 14.04.17 17:15, Juha Heinanen wrote:
Juha Heinanen writes:
domain-create.sql contains this:
CREATE TABLE `domain_attrs` ( `id` INT(10) UNSIGNED AUTO_INCREMENT PRIMARY KEY NOT NULL, `did` VARCHAR(64) NOT NULL, `name` VARCHAR(32) NOT NULL, `type` INT UNSIGNED NOT NULL, `value` VARCHAR(255) NOT NULL, `last_modified` DATETIME DEFAULT '2000-01-01 00:00:01' NOT NULL, CONSTRAINT domain_attrs_idx UNIQUE (`did`, `name`, `value`) );
Why value needs to be part of the index?
I haven't used this table myself, it's coming from SER branch, but I guess the unique constraint is for being sure there are no duplicated values for the same did/name tuple, but more records with same did and name.
If it would be just for fast searching, then a normal index should be used.
Cheers, Daniel