/**
     * Adds an adapter-specific LIMIT clause to the SELECT statement.
     *
     * @param string $sql
     * @param integer $count
     * @param integer $offset OPTIONAL
     * @return string
     * @throws Zend_Db_Adapter_Oracle_Exception
     */
    public function limit($sql, $count, $offset = 0)
    {
        $count = intval($count);
        if ($count <= 0) {
            /**
             * @see Zend_Db_Adapter_Oracle_Exception
             */
            require_once 'Zend/Db/Adapter/Oracle/Exception.php';
            throw new Zend_Db_Adapter_Oracle_Exception("LIMIT argument count=$count is not valid");
        }

        $offset = intval($offset);
        if ($offset < 0) {
            /**
             * @see Zend_Db_Adapter_Oracle_Exception
             */
            require_once 'Zend/Db/Adapter/Oracle/Exception.php';
            throw new Zend_Db_Adapter_Oracle_Exception("LIMIT argument offset=$offset is not valid");
        }

        /**
         * Oracle does not implement the LIMIT clause as some RDBMS do.
         * We have to simulate it with subqueries and ROWNUM.
         * Unfortunately because we use the column wildcard "*",
         * this puts an extra column into the query result set.
         */
        $limit_sql = "SELECT z2.*
            FROM (
                SELECT z1.*, ROWNUM AS \"zend_db_rownum\"
                FROM (
                    " . $sql . "
                ) z1
            ) z2
            WHERE z2.\"zend_db_rownum\" BETWEEN " . ($offset+1) . " AND " . ($offset+$count);
        return $limit_sql;
    }