Guess I'll still have lots to learn about linux ...
did a
lsof | grep orcexec
and it came out with a file in /var/tmp/
but searching that directory did not reveal anything!?

just guessing
Did you already do a reboot?
as I assume this to be a temporary file on rootfs.(mmcblk0p2)

I guess further that it is not your meta.db directly which is affected but the temporary file only? So a reboot should solve/heal?

If it is your meta.db file itself:
did you try to dump or backup with sqlite?
Like:
sqlite3 /home/user/.cache/tracker/meta.db
.help
.backup /home/user/meta.db.bkp
--or
.output /home/user/MyDocs/meta.db.dmp
.dump

Maybe this is possible?
But what to afterwards? At least you would have a backup...