2 -- patch-categorylinksindex.sql
4 -- Per bug 10280 / http://bugzilla.wikimedia.org/show_bug.cgi?id=10280
6 -- Improve enum continuation performance of the what pages belong to a category query
9 ALTER TABLE /*$wgDBprefix*/categorylinks
10 DROP INDEX cl_sortkey,
11 ADD INDEX cl_sortkey(cl_to, cl_sortkey, cl_from);