Upgrade from 6.4.7 to 7.0.0?

[Adnan]

I currently have JIRA core v6.4.7 on my PRODUCTION and DEV instance.
I'll be upgrading to 7.0.0 or later versions.
Currently I'm using oracle db on my JIRA instances and not the JIRA internal DB.

I wanted to know :
1) Can I upgrade to the version smoothly from 6.4.7 to 7.0.0?
     Is there some problem with the the DB as when the JIRA instance is connected to the internal db (HSQL) , I got to know that we have tojump from 6.4.7 then 6.4.14 then 7.0.0 and then to later versions....I just wanted to know if I have to dosomething like this or can I directly jump to 7.0.0 without worryig about my DB?

2) My data in the JIRA and plugin(tempo timesheets ) will remain intact right even after the upgrade?

Pls reply asap
Thanks

[AnnWorley]

You can go directly from JIRA 6.4.7 to JIRA 7.0.x but to upgrade to a higher version, you have to upgrade to 7.0.x first. There are more details in End of support for JIRA 6.4: FAQs about upgrading.

Your Oracle DB will need to be version 12c per Supported platforms.

The JIRA support team assured me your Tempo data will be "A-OK", still I would upgrade a test environment first to avoid surprises in Production.

This link may be helpful as you plan the upgrade:

Migration hub