Note that the parent variant takes a disruptive lock that will block
write DML. You might prefer to just use the first query if this is
running in a production environment.
Fortunately this has only been observed on the dev instance.
This morning I tried just dropping and recreating the index, so I'll see if that has solved it. If it has, then the root cause may remain a mystery; if not, I'll try amcheck.
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GIT d- s+ a- C++++ L+++ S++ B+ P++>++++ E++ W+++
N o? K- !w++++ O- M- V? PS++ PE- Y+ PGP t+ 5+++
X R+ tv b+++ DI++ D++ G+ e-- h- r++ y
------END GEEK CODE BLOCK------
Version: 3.12
GIT d- s+ a- C++++ L+++ S++ B+ P++>++++ E++ W+++
N o? K- !w++++ O- M- V? PS++ PE- Y+ PGP t+ 5+++
X R+ tv b+++ DI++ D++ G+ e-- h- r++ y
------END GEEK CODE BLOCK------
