"Please note you will not be able to upgrade from Oracle Certified Professional, Java SE 6 Programmer certification to Oracle Certified Professional, Java SE 8 Programmer by passing the Upgrade to Java SE 8 Programmer 1Z0-810 exam
Candidates need to earn Oracle Certified Professional, Java SE 7 Programmer credential and then pass the Upgrade to Java SE 8 Programmer 1Z0-810 exam to earn Oracle Certified Professional, Java SE 8 Programmer credential.
You can pass the Exam Upgrade to Java SE 7 Programmer 1Z0-805 to earn Oracle Certified Professional, Java SE 7 Programmer credential and then upgrade to Oracle Certified Professional, Java SE 8 Programmer credential by passing the Upgrade to Java SE 8 Programmer 1Z0-810 exam"