Editing GitLab V18 Upgrade (section)

==Important Notes:==

* **Database Restart:** For the `initdb.scripts` method, the script runs only on *initialization* of the PostgreSQL container. If your PostgreSQL pods are already running, you might need to force a recreation of the PostgreSQL primary pod for the `initdb` script to execute. Be careful doing this in a production environment as it will cause a brief database downtime. A common way to force recreation after an `initdb` change is to taint the old pods or delete them gracefully, allowing Kubernetes to reschedule new ones.
* **GitLab Database User:** Double-check the exact database user name GitLab is using. This is critical for granting permissions to the correct user.
* **PostgreSQL Version:** The `pg_ls_waldir()` function is present in PostgreSQL 10 and newer. If you are on a very old PostgreSQL version, the function might be `pg_ls_dir()`, but GitLab 18 definitely requires a modern PostgreSQL.
* **Backups:** Always ensure you have a complete and tested backup of your GitLab instance and its database before performing any major upgrade or making database permission changes.

By applying the correct `GRANT` statement to the appropriate GitLab database user, you should resolve the "permission denied for function pg_ls_waldir" error and allow your GitLab upgrade to proceed.