Hmm, that's an invalid VXID, which would ordinarily mean that nothing is holding the lock. There is a passing mention in mvcc.sgml that SIRead locks sometimes need to be held past transaction end, so maybe what you're looking at is such a lock that is no longer associated with a specific transaction. I have to disclaim knowing much of anything about the SSI code, though.
Hmm, yeah. I had seen discussion of this "held past transaction end" but didn't know what to make of it.
