--- /dev/null
+DROP TABLE IF EXISTS /*_*/user_groups_tmp;
+
+CREATE TABLE /*$wgDBprefix*/user_groups_tmp (
+ ug_user int unsigned NOT NULL default 0,
+ ug_group varbinary(255) NOT NULL default '',
+ ug_expiry varbinary(14) NULL default NULL,
+ PRIMARY KEY (ug_user, ug_group)
+);
+
+INSERT OR IGNORE INTO /*_*/user_groups_tmp (
+ ug_user, ug_group )
+ SELECT
+ ug_user, ug_group
+ FROM /*_*/user_groups;
+
+DROP TABLE /*_*/user_groups;
+
+ALTER TABLE /*_*/user_groups_tmp RENAME TO /*_*/user_groups;
+
+CREATE INDEX /*i*/ug_group ON /*_*/user_groups (ug_group);
+CREATE INDEX /*i*/ug_expiry ON /*_*/user_groups (ug_expiry);