CREATE TABLE core_domain (
id int(11) NOT NULL auto_increment,
PRIMARY KEY (id)
-);
+) ENGINE=innodb DEFAULT CHARSET=utf8 ;
+-- need to specify engine set, otherwise the unique index get's borked.
+ALTER TABLE core_domain ADD COLUMN domain VARCHAR(255) NOT NULL DEFAULT '';
-ALTER TABLE core_domain ADD COLUMN domain VARCHAR(256) NOT NULL DEFAULT '';
\ No newline at end of file
+CREATE UNIQUE INDEX ui_domain ON core_domain (domain);
\ No newline at end of file