I have listed the files during that run, I will try to add those as an attachment to the mail, no idea if the list accepts that. There were 2024 files in that directory around the end...
Executing that lsof command only produces some warnings, no files:
root@chatelet:/d2/var/lib/postgresql/15/main/base# lsof -nn |grep pgsql_tmp |grep -E 'DEL|deleted|inode|no such' lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs Output information may be incomplete. lsof: WARNING: can't stat() fuse.jetbrains-toolbox file system /tmp/.mount_jetbraOAyv5H Output information may be incomplete. lsof: WARNING: can't stat() fuse.portal file system /run/user/1000/doc Output information may be incomplete.
