@trysdyn Ah yes the joys of running arch and postgres in combination. Just lovely. Didn't know Maria had the same problem. Thats good to know.
Otherwise there is help you don't want or can upgrade postgres immediatly as a new version rolls around. Postgres normally has its releases be fixed up with patches for multiple versions some versions even are LTS.
If you acciendently upgraded you should be able to just downgrade it by downloading the respective version of postgres from the arch linux archives. Or you can hit up the AUR.
With every new major the old one gets an AUR-Package as is the case with postgres-15:
https://aur.archlinux.org/packages?O=0&SeB=nd&K=postgresql15And postgres-old-upgrade is mentioned in tge wiki to be used in the upgrade-process since you need the new and old version.
Personally I would just stick to a version of postgres as long as I can. Thank you for the PSA though. My Instance also runs arch so I know I have to look out for this
Edit: Postgres-Majirs have a livecycle of 5 years normally so sticking with whatever version you have is an option see here:
https://www.postgresql.org/support/versioning/