Backport to branch(3) : Refactor JdbcAdmin

[feeblefakie]

This is an automated request for a manual backport of the following:

• Original PR: Refactor JdbcAdmin #3121
• Commit to backport: 38fdc5a

1. Resolve any conflicts that occur during the cherry-picking process.

git fetch origin &&
git checkout 3-pull-3121 &&
git cherry-pick --no-rerere-autoupdate -m1 38fdc5a71ec72a6ce40e4732ba8eb30be8e46809

2. Push the changes.
3. Merge this PR after all checks have passed.

Thank you!