https://bamboo.isi.edu/browse/PEGASUS-WT50-JDBCPERF-710/log

021-05-28 21:25:00.269 ERROR [root] Unable to tell database DELETE l FROM rc_lfn l LEFT JOIN rc_pfn p ON p.lfn_id=l.lfn_id WHERE p.lfn_id IS NULL: Lock wait timeout exceeded; try restarting transaction
28-May-2021 21:27:03 2021-05-28 21:27:03.285 ERROR [root] Unable to tell database DELETE l FROM rc_lfn l LEFT JOIN rc_pfn p ON p.lfn_id=l.lfn_id WHERE p.lfn_id IS NULL: Lock wait timeout exceeded; try restarting transaction
28-May-2021 21:29:06 2021-05-28 21:29:06.303 ERROR [root] Unable to tell database DELETE l FROM rc_lfn l LEFT JOIN rc_pfn p ON p.lfn_id=l.lfn_id WHERE p.lfn_id IS NULL: Lock wait timeout exceeded; try restarting transaction
28-May-2021 21:31:06 2021-05-28 21:31:06.323 ERROR [root] Unable to tell database DELETE l FROM rc_lfn l LEFT JOIN rc_pfn p ON p.lfn_id=l.lfn_id WHERE p.lfn_id IS NULL: Lock wait timeout exceeded; try restarting transaction
28-May-2021 21:33:11 2021-05-28 21:33:11.378 ERROR [root] Unable to tell database DELETE l FROM rc_lfn l LEFT JOIN rc_pfn p ON p.lfn_id=l.lfn_id WHERE p.lfn_id IS NULL: Lock wait timeout exceeded; try restart

I think the deletes have to batched. not issued as a single query