Index: trunk/core/install/upgrades.sql
===================================================================
diff -u -N -r8397 -r8555
--- trunk/core/install/upgrades.sql	(.../upgrades.sql)	(revision 8397)
+++ trunk/core/install/upgrades.sql	(.../upgrades.sql)	(revision 8555)
@@ -104,3 +104,11 @@
 );
 
 ALTER TABLE Events ADD ReplacementTags TEXT AFTER Event;
+
+
+# ====== v 4.2.0 ====
+ALTER TABLE Category ADD `TreeLeft` BIGINT NOT NULL AFTER `ParentPath` ,
+ADD `TreeRight` BIGINT NOT NULL AFTER `TreeLeft` ;
+
+ALTER TABLE Category ADD INDEX ( `TreeLeft` , `TreeRight` ) ;
+