Re: found xmin from before relfrozenxid on pg_catalog.pg_authid

​#0  errmsg_internal (fmt=0x555b62e6eb70 "found xmin %u from before relfrozenxid %u") at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/utils/error/elog.c:828
        edata = <optimized out>
        __func__ = "errmsg_internal"
#1  0x0000555b62ad1cb9 in heap_prepare_freeze_tuple (tuple=<optimized out>, relfrozenxid=relfrozenxid@entry=248720453, relminmxid=relminmxid@entry=53644256, cutoff_xid=3485221679,
    cutoff_multi=<optimized out>, frz=frz@entry=0x555b640d1988, totally_frozen_p=0x7ffca32c0e90 "\001")
    at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/access/heap/heapam.c:6685
        changed = <optimized out>
        freeze_xmax = 0 '\000'
        xid = <optimized out>
        totally_frozen = <optimized out>
        __func__ = "heap_prepare_freeze_tuple"
#2  0x0000555b62bfd2b5 in lazy_scan_heap (aggressive=0 '\000', nindexes=2, Irel=0x555b64095948, vacrelstats=<optimized out>, options=26, onerel=0x555b64029498)
    at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/commands/vacuumlazy.c:1090
        tuple_totally_frozen = 1 '\001'
        itemid = 0x7f2b7bc5d4fc
        buf = 18138842
        page = <optimized out>
        offnum = 26
        maxoff = 26
        hastup = 1 '\001'
        nfrozen = 0
        freespace = <optimized out>
        all_frozen = 1 '\001'
        tupgone = 0 '\000'
        prev_dead_count = 0
        all_visible_according_to_vm = 0 '\000'
        all_visible = 1 '\001'
        has_dead_tuples = 0 '\000'
        visibility_cutoff_xid = 3490221678
        relname = 0x555b640296a8 "pg_authid"
        relminmxid = 53644256
        tups_vacuumed = 0
        indstats = 0x555b64095928
        relfrozenxid = 248720453
        skipping_blocks = 0 '\000'
        frozen = 0x555b640d1988
        initprog_val = {1, 2, 582}
        vacuumed_pages = 0
        num_tuples = 80
        nkeep = 0
        ru0 = {tv = {tv_sec = 1527175061, tv_usec = 739743}, ru = {ru_utime = {tv_sec = 0, tv_usec = 60000}, ru_stime = {tv_sec = 1, tv_usec = 416000}, {ru_maxrss = 9704,
              __ru_maxrss_word = 9704}, {ru_ixrss = 0, __ru_ixrss_word = 0}, {ru_idrss = 0, __ru_idrss_word = 0}, {ru_isrss = 0, __ru_isrss_word = 0}, {ru_minflt = 33982,
              __ru_minflt_word = 33982}, {ru_majflt = 0, __ru_majflt_word = 0}, {ru_nswap = 0, __ru_nswap_word = 0}, {ru_inblock = 0, __ru_inblock_word = 0}, {ru_oublock = 8,
              __ru_oublock_word = 8}, {ru_msgsnd = 0, __ru_msgsnd_word = 0}, {ru_msgrcv = 0, __ru_msgrcv_word = 0}, {ru_nsignals = 0, __ru_nsignals_word = 0}, {ru_nvcsw = 38446,
              __ru_nvcsw_word = 38446}, {ru_nivcsw = 2, __ru_nivcsw_word = 2}}}
        vmbuffer = 8763411
        empty_pages = 0
        nunused = 0
        i = <optimized out>
        next_unskippable_block = <optimized out>
        buf = {data = 0x1 <error: Cannot access memory at address 0x1>, len = -1557393520, maxlen = 32764, cursor = -1557393616}
        nblocks = 2
        blkno = <optimized out>
        tuple = {t_len = 144, t_self = {ip_blkid = {bi_hi = 0, bi_lo = 1}, ip_posid = 26}, t_tableOid = 1260, t_data = 0x7f2b7bc5e6b0}
        initprog_index = {0, 1, 5}
#3  lazy_vacuum_rel (onerel=onerel@entry=0x555b64029498, options=options@entry=1, params=params@entry=0x7ffca32c11b0, bstrategy=<optimized out>)
    at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/commands/vacuumlazy.c:253
        vacrelstats = <optimized out>
        Irel = 0x555b64095948
        nindexes = 2
        ru0 = {tv = {tv_sec = 93850993708032, tv_usec = 23936}, ru = {ru_utime = {tv_sec = 128, tv_usec = 93851007694584}, ru_stime = {tv_sec = 0, tv_usec = 0}, {ru_maxrss = 140723046059424,
              __ru_maxrss_word = 140723046059424}, {ru_ixrss = 93850989549501, __ru_ixrss_word = 93850989549501}, {ru_idrss = 16, __ru_idrss_word = 16}, {ru_isrss = 93851007694584,
              __ru_isrss_word = 93851007694584}, {ru_minflt = 140723046059472, __ru_minflt_word = 140723046059472}, {ru_majflt = 93850989559601, __ru_majflt_word = 93850989559601}, {
              ru_nswap = 93850994010032, __ru_nswap_word = 93850994010032}, {ru_inblock = 139833259949608, __ru_inblock_word = 139833259949608}, {ru_oublock = 93850994010032,
              __ru_oublock_word = 93850994010032}, {ru_msgsnd = 93851008239032, __ru_msgsnd_word = 93851008239032}, {ru_msgrcv = 140723046059904, __ru_msgrcv_word = 140723046059904}, {
              ru_nsignals = 93850989313526, __ru_nsignals_word = 93850989313526}, {ru_nvcsw = 345176855416, __ru_nvcsw_word = 345176855416}, {ru_nivcsw = 140723046059551,
              __ru_nivcsw_word = 140723046059551}}}
        starttime = 0
        secs = 1527175061
        usecs = 144
        read_rate = <optimized out>
        write_rate = <optimized out>
        aggressive = 0 '\000'
        scanned_all_unfrozen = <optimized out>
        xidFullScanLimit = 3440221679
        mxactFullScanLimit = 4204418425
        new_rel_pages = <optimized out>
        new_rel_tuples = <optimized out>
        new_rel_allvisible = 2737573328
        new_live_tuples = <optimized out>
        new_frozen_xid = <optimized out>
        new_min_multi = <optimized out>
        __func__ = "lazy_vacuum_rel"
#4  0x0000555b62bfa54d in vacuum_rel (relid=relid@entry=1260, relation=relation@entry=0x555b64047100, options=options@entry=1, params=params@entry=0x7ffca32c11b0)
    at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/commands/vacuum.c:1391
        lmode = 4
        onerel = 0x555b64029498
        onerelid = {relId = 1260, dbId = 0}
        toast_relid = 0
        save_userid = 10
        save_sec_context = 0
        save_nestlevel = 2
        __func__ = "vacuum_rel"
#5  0x0000555b62bfb545 in vacuum (options=1, relation=0x555b64047100, relid=relid@entry=0, params=params@entry=0x7ffca32c11b0, va_cols=0x0, bstrategy=<optimized out>, bstrategy@entry=0x0,
    isTopLevel=1 '\001') at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/commands/vacuum.c:303
        relid = 1260
        cur = 0x555b640998b8
        save_exception_stack = 0x7ffca32c1590
        save_context_stack = 0x0
        local_sigjmp_buf = {{__jmpbuf = {93851008735448, -4513934124599105488, 93850994009984, 93851008619616, 93851008619616, 93851008398480, -4513934124655728592, -7776366411743385552},
            __mask_was_saved = 0, __saved_mask = {__val = {0, 0, 0, 0, 1, 1, 1, 3473119737632784380, 139833388464563, 140723046060384, 12, 140723046060912, 93850990837571,
                4049721212982268568, 1, 140723046060432}}}}
        stmttype = <optimized out>
        in_outer_xact = 0 '\000'
        use_own_xacts = 1 '\001'
        relations = 0x555b640998d8
        in_vacuum = 1 '\001'
        __func__ = "vacuum"
#6  0x0000555b62bfb8ca in ExecVacuum (vacstmt=vacstmt@entry=0x555b64047150, isTopLevel=isTopLevel@entry=1 '\001')
    at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/commands/vacuum.c:121
        params = {freeze_min_age = -1, freeze_table_age = -1, multixact_freeze_min_age = -1, multixact_freeze_table_age = -1, is_wraparound = 0 '\000', log_min_duration = -1}
#7  0x0000555b62d27787 in standard_ProcessUtility (parsetree=0x555b64047150, queryString=0x555b64046688 "vacuum pg_catalog.pg_authid;", context=<optimized out>, params=0x0,
    dest=0x555b64047490, completionTag=0x7ffca32c19c0 "") at /build/postgresql-9.6-9VrjLn/postgresql-9.6-9.6.8/build/../src/backend/tcop/utility.c:655
        stmt = 0x555b64047150
        isTopLevel = <optimized out>
        __func__ = "standard_ProcessUtility"
​