Database Query of Users from UserlistProvider is very slow

Script to create 1000 users in Opencast:
COUNTER=1
while [ $COUNTER -lt 1000 ]; do
echo The counter is $COUNTER

#create Group
curl -i --digest -u opencast_system_account:CHANGE_ME -H 'X-Requested-Auth: Digest' \
http://localhost:8080/groups -F name=$COUNTER

#create User
curl -i --digest -u opencast_system_account:CHANGE_ME -H 'X-Requested-Auth: Digest' \
http://localhost:8080/admin-ng/users -F username=$COUNTER -F password=$COUNTER -F name=$COUNTER -F roles='ROLE_GROUP_'$COUNTER

let COUNTER=COUNTER+1
done

Two related issues: and

The change to lazy loading for JpaUser (similarly for JpaUserReference) eliminates a query per user of this form:

SELECT t1.id, t1.description, t1.name, t1.organization FROM mh_user_role t0, mh_role t1 WHERE ((t0.user_id = 29598) AND (t1.id = t0.role_id))

The performance impact of this issue is not in the query time for any individual query, but just the volume of queries (one per user).