protected function _process( $stmts )
	{
		$this->_msg( 'Renameing shipping to costs in catalog index price table', 0 );

		if( $this->_schema->tableExists( 'mshop_catalog_index_price' ) === true
			&& $this->_schema->columnExists( 'mshop_catalog_index_price', 'shipping' ) === true )
		{
			$this->_execute( $stmts );
			$this->_status( 'done' );
		}
		else
		{
			$this->_status( 'OK' );
		}
	}