Is that considered an actionable problem? Encountered while trying to reproduce the vacuum full pg_statistic/toast_2619 bug; while running a loop around VAC FULL and more in another session: [1]- Running { time sh -ec 'while :; do psql --port 5678 postgres -qc "VACUUM FULL pg_toast.pg_toast_2619"; psql --port 5678 postgres -qc "VACUUM FULL pg_statistic"; done'; date; } & [2]+ Running time while :; do psql postgres --port 5678 -c "INSERT INTO t SELECT i FROM generate_series(1,999999) i"; sleep 1; for a in `seq 999`; do psql postgres --port 5678 -c "ALTER TABLE t ALTER i TYPE int USING i::int"; sleep 1; psql postgres --port 5678 -c "ALTER TABLE t ALTER i TYPE bigint"; sleep 1; done; psql postgres --port 5678 -c "TRUNCATE t"; sleep 1; done & [pryzbyj@kgfs66telsadb ~]$ psql --port 5678 postgres -x psql (11beta1) Type "help" for help. ... postgres=# \set VERBOSITY verbose postgres=# \d t ERROR: XX000: cache lookup failed for relation 8096742 LOCATION: flatten_reloptions, ruleutils.c:11065 Justin