When updating your system on archlinux with pacman -Suy, pacman gets package databases from somewhere and then downloads packages from mirrors according to versions specified in these databases.
I know these databases are in /var/lib/pacman/sync/. My question is, where does pacman get them from?
The db files also come from the package mirrors specified in /etc/pacman.d/mirrorlist.
For example in this core repo:
...
core.db 136.6 KiB 2022-Mar-05 12:53
core.db.tar.gz 136.6 KiB 2022-Mar-05 12:53
...
The wiki also mentions what to do if you get an error:
Failed retrieving file 'core.db' from mirror
If you receive this error message with correct mirrors, try setting a different name server.