Changed my mind about how I want to do this.

sql/database-create.sql

@@ -2183,6 +2183,8 @@ CREATE TABLE `image_versions` (
 DROP TABLE IF EXISTS `image_updates`;
 CREATE TABLE `image_updates` (
   `imageid` int(8) unsigned NOT NULL default '0',
+  `updater` varchar(8) default NULL,
+  `updater_idx` mediumint(8) unsigned NOT NULL default '0',
   `updater_urn` varchar(128) default NULL,
   `url` varchar(255) NOT NULL default '',
   PRIMARY KEY  (`imageid`)

sql/updates/4/472

@@ -5,9 +5,21 @@ sub DoUpdate($$$)
 {
     my ($dbhandle, $dbname, $version) = @_;
 
+    if (!DBSlotExists("image_updates", "updater")) {
+	DBQueryFatal("ALTER TABLE image_updates ADD ".
+		     " `updater` varchar(8) default NULL ".
+		     "    AFTER imageid");
+    }
+    if (!DBSlotExists("image_updates", "updater_idx")) {
+	DBQueryFatal("ALTER TABLE image_updates ADD ".
+		     " `updater_idx` mediumint(8) unsigned NOT NULL ".
+		     "    default '0'".
+		     "    AFTER updater");
+    }
     if (!DBSlotExists("image_updates", "updater_urn")) {
 	DBQueryFatal("ALTER TABLE image_updates ADD ".
-		     " `updater_urn` varchar(128) default NULL AFTER imageid");
+		     " `updater_urn` varchar(128) default NULL ".
+		     "    AFTER updater_idx");
     }
     return 0;
 }