text: VACUUM;
  
  --
  -- sanity check, if we don't have indices the test will take years to
  -- complete.  But skip TOAST relations (since they will have varying
  -- names depending on the current OID counter) as well as temp tables
  -- of other backends (to avoid timing-dependent behavior).
  --
  SELECT relname, relhasindex
     FROM pg_class c LEFT JOIN pg_namespace n ON n.oid = relnamespace
     WHERE relkind = 'r' AND (nspname ~ '^pg_temp_') IS NOT TRUE
     ORDER BY relname;
  
  --
  -- another sanity check: every system catalog that has OIDs should have
  -- a unique index on OID.  This ensures that the OIDs will be unique,
  -- even after the OID counter wraps around.
  -- We exclude non-system tables from the check by looking at nspname.
  --
  SELECT relname, nspname
  FROM pg_class c LEFT JOIN pg_namespace n ON n.oid = relnamespace
  WHERE relhasoids
      AND ((nspname ~ '^pg_') IS NOT FALSE)
      AND NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = c.oid
                      AND indkey[0] = -2 AND indnatts = 1
                      AND indisunique AND indimmediate);
  