if I’m right, there is no openHAB 2 addon
All I found is … openhab1-addons/…/org.openhab.persistence.jdbc

Anybody working on openHAb2 upgrade of this add-on?
Or am I a little bit blind only?

Persistence services for OH2 remain essentially the OH1 services. There are few disadvantages to that, perhaps the only significant one is failing to take Units of Measurement fully into account.
That’s not going to change at this point in OH2 life cycle, with development efforts focused on OH3…

All of the 1.x persistence addons have been migrated to 2.x in OH 3.0 and the PRs have been merged. You can find them in Github (both OHC and OHA).

would be nice, if one tells me which repository holds OH 3.0 and maybe how to access it if it’s hidden.

by creating an account on GitHub.
is that the trick?

The GitHub URL points to location were the source code of the OH 3 persistence add-ons are located. The text shown is just part of the text this forum takes from websites if you post a link.

yes, thanks, I got it.
It was a little bit strange. First try was to do a git clone of addons repository with explizit setting to master branche. But this did a fallback to openpab2.5 branch on the subs.
Only direct download gave me contents of addons master branch.

If you clone it will probably checkout the default branch, which is currently 2.5.x. To get the OH3 branch, aka master you need to checkout git checkout master.
Whenever you clone you always get all branches.