--- /dev/null
+CREATE TABLE /*_*/user_groups_tmp (
+ ug_user int unsigned NOT NULL default 0,
+ ug_group varbinary(255) NOT NULL default ''
+) /*$wgDBTableOptions*/;
+
+INSERT INTO /*_*/user_groups_tmp
+ SELECT ug_user, ug_group
+ FROM /*_*/user_groups;
+
+DROP TABLE /*_*/user_groups;
+
+ALTER TABLE /*_*/user_groups_tmp RENAME TO /*_*/user_groups;
+
+CREATE UNIQUE INDEX /*i*/ug_user_group ON /*_*/user_groups (ug_user,ug_group);
+CREATE INDEX /*i*/ug_group ON /*_*/user_groups (ug_group);