seq: sequences

Sequences of this database by how much of their range is used; FAIL when one is exhausted.

Captured on 2026-10-07 (UTC+08) on a local KingbaseES V008R006C009B0014 primary and standby, database test, using ~/kbdiag built from Go source commit 96c874f (static linux/amd64 binary). This is lab evidence, not production validation. The FAIL example was created by an injection script: it created public.kbdiag_inj_seq with maxvalue 3 and used it up with nextval. Values belong to this capture only.

Usage

kbdiag seq [--limit N] [--json]

Option	Effect
`--limit N`	Show at most N sequences; default 20, `0` for all
`--json`	Print JSON

Connection options are the same as for sessions and it looks at the database you are connected to. --limit only trims the list; the finding covers every sequence.

Primary

~/kbdiag seq
echo EXIT_CODE=$?

seq  OK  (KingbaseES V008R006C009B0014, primary, system@local, 2026-10-07T17:21:00+08:00)

sequences in test: 16, most used first
  sequence                                type     last     limit                used   left
  public.kbdiag_test_id_seq               integer  1311000  2147483647           0.06%  2.15e+09
  kdb_schedule.kdb_jobclass_jclid_seq     integer  5        2147483647           0.00%  2.15e+09
  perf.kwr_snapshots_snap_id_seq          integer  2        2147483647           0.00%  2.15e+09
  public.flight_psg_new_info_id_seq       bigint   1000000  9223372036854775807  0.00%  9.22e+18
  public.orders_id_seq                    bigint   1000000  9223372036854775807  0.00%  9.22e+18
  public.t_perf_test_id_seq               bigint   100000   9223372036854775807  0.00%  9.22e+18
  sysmac.sysmac_policy_oid_seq            bigint   1        9223372036854775807  0.00%  9.22e+18
  kdb_schedule.kdb_action_acid_seq        integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_exception_jexid_seq    integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_job_action_jaid_seq    integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_joblog_jlgid_seq       integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_jobsteplog_jslid_seq   integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_schedule_job_sjid_seq  integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_schedule_scid_seq      integer  -        2147483647           -      no value yet
  sys_catalog.global_chain_seq            bigint   -        9223372036854775807  -      no value yet
  sys_hm.hm_run_t_run_id_seq              integer  -        2147483647           -      no value yet
EXIT_CODE=0

The sequences are ordered by how much of their range is used. last is the last value handed out, limit the end of the range it counts toward (its own MAXVALUE, or MINVALUE for a descending one), used the share, left how many values remain. The arithmetic is exact (math/big), since a bigint sequence spans the whole int64 range and plain subtraction would overflow.
A sequence that has never been called, or was reset with setval(..., false), has no last value: it is shown as no value yet, with -.
Only one thing is judged: seq.exhausted (FAIL), when nextval already fails. A sequence that merely runs low is shown, not reported: how low is too low has no objective line. A sequence that cycles does not count as used up; it would be written as cycles (not captured in the lab).

Standby

~/kbdiag seq
echo EXIT_CODE=$?

seq  OK  (KingbaseES V008R006C009B0014, standby, system@local, 2026-10-07T17:21:07+08:00)

sequences in test: 16, most used first
  on a standby a sequence reads up to 32 values ahead of the primary (and is not judged): run on the primary
  sequence                                type     last     limit                used   left
  public.kbdiag_test_id_seq               integer  1311029  2147483647           0.06%  2.15e+09
  kdb_schedule.kdb_jobclass_jclid_seq     integer  33       2147483647           0.00%  2.15e+09
  perf.kwr_snapshots_snap_id_seq          integer  33       2147483647           0.00%  2.15e+09
  public.flight_psg_new_info_id_seq       bigint   1000032  9223372036854775807  0.00%  9.22e+18
  public.orders_id_seq                    bigint   1000032  9223372036854775807  0.00%  9.22e+18
  public.t_perf_test_id_seq               bigint   100023   9223372036854775807  0.00%  9.22e+18
  sysmac.sysmac_policy_oid_seq            bigint   1        9223372036854775807  0.00%  9.22e+18
  kdb_schedule.kdb_action_acid_seq        integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_exception_jexid_seq    integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_job_action_jaid_seq    integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_joblog_jlgid_seq       integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_jobsteplog_jslid_seq   integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_schedule_job_sjid_seq  integer  -        2147483647           -      no value yet
  kdb_schedule.kdb_schedule_scid_seq      integer  -        2147483647           -      no value yet
  sys_catalog.global_chain_seq            bigint   -        9223372036854775807  -      no value yet
  sys_hm.hm_run_t_run_id_seq              integer  -        2147483647           -      no value yet
EXIT_CODE=0

A standby’s sequence value is the copy in the WAL, and the primary writes 32 values ahead each time, so a standby can read “at the end” while the primary still has values. The text says so (up to 32 values ahead of the primary), and the standby is not judged: run seq on the primary. The last values above are indeed larger than the primary’s.

Without privileges

kbdiag_ro (no monitoring role, over 127.0.0.1):

PGPASSWORD=... ~/kbdiag --host 127.0.0.1 -U kbdiag_ro seq
echo EXIT_CODE=$?

seq  UNKNOWN  (KingbaseES V008R006C009B0014, primary, kbdiag_ro@remote, 2026-10-07T17:21:08+08:00)

sequences in test: 16, most used first
  sequence                                type     last  limit                used  left
  kdb_schedule.kdb_action_acid_seq        integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_exception_jexid_seq    integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_job_action_jaid_seq    integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_jobclass_jclid_seq     integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_joblog_jlgid_seq       integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_jobsteplog_jslid_seq   integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_schedule_job_sjid_seq  integer  ?     2147483647           ?     ?
  kdb_schedule.kdb_schedule_scid_seq      integer  ?     2147483647           ?     ?
  perf.kwr_snapshots_snap_id_seq          integer  ?     2147483647           ?     ?
  public.flight_psg_new_info_id_seq       bigint   ?     9223372036854775807  ?     ?
  public.kbdiag_test_id_seq               integer  ?     2147483647           ?     ?
  public.orders_id_seq                    bigint   ?     9223372036854775807  ?     ?
  public.t_perf_test_id_seq               bigint   ?     9223372036854775807  ?     ?
  sys_catalog.global_chain_seq            bigint   -     9223372036854775807  -     no value yet
  sys_hm.hm_run_t_run_id_seq              integer  -     2147483647           -     no value yet
  sysmac.sysmac_policy_oid_seq            bigint   ?     9223372036854775807  ?     ?
redacted: 14 rows of seq.list hide last_value (insufficient_privilege; grant SELECT on the sequences (sys_monitor does not cover them))
EXIT_CODE=3

? is a last_value this account may not read (no SELECT on the sequence), so used and left cannot be computed. The SQL checks the privilege by oid, so a sequence dropped meanwhile does not fail the whole probe. The 14 hidden rows are in redacted, with the advice to grant SELECT on the sequences: sys_monitor does not cover them.
The two rows with - are sequences never called (no value yet): that is not the same NULL as a privilege gap, and kbdiag keeps the two apart.
The verdict is UNKNOWN, because it could not see the values.

An exhausted sequence

~/kbdiag seq
echo EXIT_CODE=$?

seq  FAIL  (KingbaseES V008R006C009B0014, primary, system@local, 2026-10-07T17:21:20+08:00)

[FAIL] seq.exhausted  sequence public.kbdiag_inj_seq (integer) is at 3, its limit is 3: nextval fails, so inserts that use it fail
  fix: ALTER SEQUENCE public.kbdiag_inj_seq MAXVALUE <higher>  # it stops at its MAXVALUE, short of what its type allows

sequences in test: 17, most used first
  sequence                                type     last     limit                used     left
  public.kbdiag_inj_seq                   integer  3        3                    100.00%  0
  public.kbdiag_test_id_seq               integer  1311000  2147483647           0.06%    2.15e+09
  kdb_schedule.kdb_jobclass_jclid_seq     integer  5        2147483647           0.00%    2.15e+09
  perf.kwr_snapshots_snap_id_seq          integer  2        2147483647           0.00%    2.15e+09
  public.flight_psg_new_info_id_seq       bigint   1000000  9223372036854775807  0.00%    9.22e+18
  public.orders_id_seq                    bigint   1000000  9223372036854775807  0.00%    9.22e+18
  public.t_perf_test_id_seq               bigint   100000   9223372036854775807  0.00%    9.22e+18
  sysmac.sysmac_policy_oid_seq            bigint   1        9223372036854775807  0.00%    9.22e+18
  kdb_schedule.kdb_action_acid_seq        integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_exception_jexid_seq    integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_job_action_jaid_seq    integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_joblog_jlgid_seq       integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_jobsteplog_jslid_seq   integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_schedule_job_sjid_seq  integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_schedule_scid_seq      integer  -        2147483647           -        no value yet
  sys_catalog.global_chain_seq            bigint   -        9223372036854775807  -        no value yet
  sys_hm.hm_run_t_run_id_seq              integer  -        2147483647           -        no value yet
EXIT_CODE=2

seq.exhausted is a FAIL: nextval fails, so inserts that use it already fail. The line is the sequence’s own limit, so there is no option for it.
The fix depends on what blocks it. Here the sequence stops at its own MAXVALUE 3, short of what integer allows, so it raises that. When the sequence is at the limit of its type, an int or smallint becomes bigint (change the column first; this rewrites the table), and a bigint has no remedy but a new key. A sequence with a mismatched bigint sequence on an int column, where the column overflows first, is not detected.

The same database on the standby:

~/kbdiag seq
echo EXIT_CODE=$?

seq  OK  (KingbaseES V008R006C009B0014, standby, system@local, 2026-10-07T17:21:21+08:00)

sequences in test: 17, most used first
  on a standby a sequence reads up to 32 values ahead of the primary (and is not judged): run on the primary
  sequence                                type     last     limit                used     left
  public.kbdiag_inj_seq                   integer  3        3                    100.00%  0
  public.kbdiag_test_id_seq               integer  1311029  2147483647           0.06%    2.15e+09
  kdb_schedule.kdb_jobclass_jclid_seq     integer  33       2147483647           0.00%    2.15e+09
  perf.kwr_snapshots_snap_id_seq          integer  33       2147483647           0.00%    2.15e+09
  public.flight_psg_new_info_id_seq       bigint   1000032  9223372036854775807  0.00%    9.22e+18
  public.orders_id_seq                    bigint   1000032  9223372036854775807  0.00%    9.22e+18
  public.t_perf_test_id_seq               bigint   100023   9223372036854775807  0.00%    9.22e+18
  sysmac.sysmac_policy_oid_seq            bigint   1        9223372036854775807  0.00%    9.22e+18
  kdb_schedule.kdb_action_acid_seq        integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_exception_jexid_seq    integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_job_action_jaid_seq    integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_joblog_jlgid_seq       integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_jobsteplog_jslid_seq   integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_schedule_job_sjid_seq  integer  -        2147483647           -        no value yet
  kdb_schedule.kdb_schedule_scid_seq      integer  -        2147483647           -        no value yet
  sys_catalog.global_chain_seq            bigint   -        9223372036854775807  -        no value yet
  sys_hm.hm_run_t_run_id_seq              integer  -        2147483647           -        no value yet
EXIT_CODE=0

Same 100.00% row, and the standby still says OK because it does not judge sequences.

Exit codes

Code	Meaning
0	OK
2	FAIL: a sequence cannot hand out another value
3	UNKNOWN: data not collected or not visible
64	Usage error
69	Cannot connect

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