Improve perfomance issue for DELETE command

Author: zzet

lib/closure_tree/hierarchy_maintenance.rb

@@ -98,8 +98,9 @@ def delete_hierarchy_references
  FROM (SELECT descendant_id
  FROM #{_ct.quoted_hierarchy_table_name}
  WHERE ancestor_id = #{_ct.quote(id)}
- ) AS x )
- OR descendant_id = #{_ct.quote(id)}
+ ) AS x );
+ DELETE FROM #{_ct.quoted_hierarchy_table_name}
+ WHERE descendant_id = #{_ct.quote(id)}
  SQL
  end
  end