root/trunk/data/migrations/005_m1.php

<?php
class Migration005 extends sfMigration 
{

  public function up() 
  {
    $this->executeSQL("ALTER TABLE `tag` 
      ADD `is_triple` INT( 11 ) NULL ,
      ADD `triple_namespace` VARCHAR( 100 ) NULL ,
      ADD `triple_key` VARCHAR( 100 ) NULL ,
      ADD `triple_value` VARCHAR( 100 ) NULL ;");
    $this->executeSQL("ALTER TABLE `tag` ADD INDEX ( `triple_namespace` , `triple_key` , `triple_value` );");
    $this->executeSQL("ALTER TABLE `tagging` CHANGE `tag_id` `tag_id` INT( 11 ) NOT NULL"); 
    $this->executeSQL("RENAME TABLE symfonians.tag  TO symfonians.sf_tag;");
    $this->executeSQL("RENAME TABLE symfonians.tagging  TO symfonians.sf_tagging;");
  }

  public function down() 
  {
    $this->executeSQL("ALTER TABLE `sf_tag`
      DROP `is_triple`,
      DROP `triple_namespace`,
      DROP `triple_key`,
      DROP `triple_value`;");
    $this->executeSQL("RENAME TABLE symfonians.sf_tag  TO symfonians.tag;");
    $this->executeSQL("RENAME TABLE symfonians.sf_tagging  TO symfonians.tagging;");
  }

}