Standardize LSN formatting by zero padding

This commit standardizes the output format for LSNs to ensure consistent
representation across various tools and messages.  Previously, LSNs were
inconsistently printed as `%X/%X` in some contexts, while others used
zero-padding.  This often led to confusion when comparing.

To address this, the LSN format is now uniformly set to `%X/%08X`,
ensuring the lower 32-bit part is always zero-padded to eight
hexadecimal digits.

Author: Japin Li <[email protected]>
Reviewed-by: Masahiko Sawada <[email protected]>
Reviewed-by: Álvaro Herrera <[email protected]>
Discussion: https://postgr.es/m/ME0P300MB0445CA53CA0E4B8C1879AF84B641A@ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM

7 files changed, 93 insertions, 93 deletions

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 4f9192316e0..aa5b8772436 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -7971,7 +7971,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
       </para>
       <para>
        Finish LSN of the transaction whose changes are to be skipped, if a valid
-       LSN; otherwise <literal>0/0</literal>.
+       LSN; otherwise <literal>0/0000000</literal>.
       </para></entry>
      </row>
 
diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml
index c32e6bc000d..f317ed9c50e 100644
--- a/doc/src/sgml/logical-replication.sgml
+++ b/doc/src/sgml/logical-replication.sgml
@@ -575,8 +575,8 @@ HINT:  To initiate replication, you must manually create the replication slot, e
 <programlisting>
 /* pub # */ SELECT * FROM pg_create_logical_replication_slot('sub1', 'pgoutput');
  slot_name |    lsn
------------+-----------
- sub1      | 0/19404D0
+-----------+------------
+ sub1      | 0/019404D0
 (1 row)
 </programlisting></para>
      </listitem>
@@ -617,8 +617,8 @@ HINT:  To initiate replication, you must manually create the replication slot, e
 <programlisting>
 /* pub # */ SELECT * FROM pg_create_logical_replication_slot('myslot', 'pgoutput');
  slot_name |    lsn
------------+-----------
- myslot    | 0/19059A0
+-----------+------------
+ myslot    | 0/019059A0
 (1 row)
 </programlisting></para>
      </listitem>
@@ -655,8 +655,8 @@ HINT:  To initiate replication, you must manually create the replication slot, e
 <programlisting>
 /* pub # */ SELECT * FROM pg_create_logical_replication_slot('myslot', 'pgoutput');
  slot_name |    lsn
------------+-----------
- myslot    | 0/1905930
+-----------+------------
+ myslot    | 0/01905930
 (1 row)
 </programlisting></para>
      </listitem>
@@ -1965,15 +1965,15 @@ DETAIL:  <replaceable class="parameter">detailed_explanation</replaceable>.
 ERROR:  conflict detected on relation "public.test": conflict=insert_exists
 DETAIL:  Key already exists in unique index "t_pkey", which was modified locally in transaction 740 at 2024-06-26 10:47:04.727375+08.
 Key (c)=(1); existing local tuple (1, 'local'); remote tuple (1, 'remote').
-CONTEXT:  processing remote data for replication origin "pg_16395" during "INSERT" for replication target relation "public.test" in transaction 725 finished at 0/14C0378
+CONTEXT:  processing remote data for replication origin "pg_16395" during "INSERT" for replication target relation "public.test" in transaction 725 finished at 0/014C0378
 </screen>
    The LSN of the transaction that contains the change violating the constraint and
-   the replication origin name can be found from the server log (LSN 0/14C0378 and
+   the replication origin name can be found from the server log (LSN 0/014C0378 and
    replication origin <literal>pg_16395</literal> in the above case).  The
    transaction that produced the conflict can be skipped by using
    <link linkend="sql-altersubscription-params-skip"><command>ALTER SUBSCRIPTION ... SKIP</command></link>
    with the finish LSN
-   (i.e., LSN 0/14C0378).  The finish LSN could be an LSN at which the transaction
+   (i.e., LSN 0/014C0378).  The finish LSN could be an LSN at which the transaction
    is committed or prepared on the publisher.  Alternatively, the transaction can
    also be skipped by calling the <link linkend="pg-replication-origin-advance">
    <function>pg_replication_origin_advance()</function></link> function.
@@ -1984,7 +1984,7 @@ CONTEXT:  processing remote data for replication origin "pg_16395" during "INSER
    <link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>
    option. Then, you can use <function>pg_replication_origin_advance()</function>
    function with the <parameter>node_name</parameter> (i.e., <literal>pg_16395</literal>)
-   and the next LSN of the finish LSN (i.e., 0/14C0379).  The current position of
+   and the next LSN of the finish LSN (i.e., 0/014C0379).  The current position of
    origins can be seen in the <link linkend="view-pg-replication-origin-status">
    <structname>pg_replication_origin_status</structname></link> system view.
    Please note that skipping the whole transaction includes skipping changes that
diff --git a/doc/src/sgml/logicaldecoding.sgml b/doc/src/sgml/logicaldecoding.sgml
index a45a1412416..593f784b69d 100644
--- a/doc/src/sgml/logicaldecoding.sgml
+++ b/doc/src/sgml/logicaldecoding.sgml
@@ -57,14 +57,14 @@
 postgres=# -- Create a slot named 'regression_slot' using the output plugin 'test_decoding'
 postgres=# SELECT * FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding', false, true);
     slot_name    |    lsn
------------------+-----------
- regression_slot | 0/16B1970
+-----------------+------------
+ regression_slot | 0/016B1970
 (1 row)
 
 postgres=# SELECT slot_name, plugin, slot_type, database, active, restart_lsn, confirmed_flush_lsn FROM pg_replication_slots;
     slot_name    |    plugin     | slot_type | database | active | restart_lsn | confirmed_flush_lsn
------------------+---------------+-----------+----------+--------+-------------+-----------------
- regression_slot | test_decoding | logical   | postgres | f      | 0/16A4408   | 0/16A4440
+-----------------+---------------+-----------+----------+--------+-------------+---------------------
+ regression_slot | test_decoding | logical   | postgres | f      | 0/016A4408  | 0/016A4440
 (1 row)
 
 postgres=# -- There are no changes to see yet
@@ -78,10 +78,10 @@ CREATE TABLE
 
 postgres=# -- DDL isn't replicated, so all you'll see is the transaction
 postgres=# SELECT * FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL);
-    lsn    |  xid  |     data
------------+-------+--------------
- 0/BA2DA58 | 10297 | BEGIN 10297
- 0/BA5A5A0 | 10297 | COMMIT 10297
+    lsn     |  xid  |     data
+------------+-------+--------------
+ 0/0BA2DA58 | 10297 | BEGIN 10297
+ 0/0BA5A5A0 | 10297 | COMMIT 10297
 (2 rows)
 
 postgres=# -- Once changes are read, they're consumed and not emitted
@@ -97,41 +97,41 @@ postgres=*# INSERT INTO data(data) VALUES('2');
 postgres=*# COMMIT;
 
 postgres=# SELECT * FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL);
-    lsn    |  xid  |                          data
------------+-------+---------------------------------------------------------
- 0/BA5A688 | 10298 | BEGIN 10298
- 0/BA5A6F0 | 10298 | table public.data: INSERT: id[integer]:1 data[text]:'1'
- 0/BA5A7F8 | 10298 | table public.data: INSERT: id[integer]:2 data[text]:'2'
- 0/BA5A8A8 | 10298 | COMMIT 10298
+    lsn     |  xid  |                          data
+------------+-------+---------------------------------------------------------
+ 0/0BA5A688 | 10298 | BEGIN 10298
+ 0/0BA5A6F0 | 10298 | table public.data: INSERT: id[integer]:1 data[text]:'1'
+ 0/0BA5A7F8 | 10298 | table public.data: INSERT: id[integer]:2 data[text]:'2'
+ 0/0BA5A8A8 | 10298 | COMMIT 10298
 (4 rows)
 
 postgres=# INSERT INTO data(data) VALUES('3');
 
 postgres=# -- You can also peek ahead in the change stream without consuming changes
 postgres=# SELECT * FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL);
-    lsn    |  xid  |                          data
------------+-------+---------------------------------------------------------
- 0/BA5A8E0 | 10299 | BEGIN 10299
- 0/BA5A8E0 | 10299 | table public.data: INSERT: id[integer]:3 data[text]:'3'
- 0/BA5A990 | 10299 | COMMIT 10299
+    lsn     |  xid  |                          data
+------------+-------+---------------------------------------------------------
+ 0/0BA5A8E0 | 10299 | BEGIN 10299
+ 0/0BA5A8E0 | 10299 | table public.data: INSERT: id[integer]:3 data[text]:'3'
+ 0/0BA5A990 | 10299 | COMMIT 10299
 (3 rows)
 
 postgres=# -- The next call to pg_logical_slot_peek_changes() returns the same changes again
 postgres=# SELECT * FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL);
-    lsn    |  xid  |                          data
------------+-------+---------------------------------------------------------
- 0/BA5A8E0 | 10299 | BEGIN 10299
- 0/BA5A8E0 | 10299 | table public.data: INSERT: id[integer]:3 data[text]:'3'
- 0/BA5A990 | 10299 | COMMIT 10299
+    lsn     |  xid  |                          data
+------------+-------+---------------------------------------------------------
+ 0/0BA5A8E0 | 10299 | BEGIN 10299
+ 0/0BA5A8E0 | 10299 | table public.data: INSERT: id[integer]:3 data[text]:'3'
+ 0/0BA5A990 | 10299 | COMMIT 10299
 (3 rows)
 
 postgres=# -- options can be passed to output plugin, to influence the formatting
 postgres=# SELECT * FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL, 'include-timestamp', 'on');
-    lsn    |  xid  |                          data
------------+-------+---------------------------------------------------------
- 0/BA5A8E0 | 10299 | BEGIN 10299
- 0/BA5A8E0 | 10299 | table public.data: INSERT: id[integer]:3 data[text]:'3'
- 0/BA5A990 | 10299 | COMMIT 10299 (at 2017-05-10 12:07:21.272494-04)
+    lsn     |  xid  |                          data
+------------+-------+---------------------------------------------------------
+ 0/0BA5A8E0 | 10299 | BEGIN 10299
+ 0/0BA5A8E0 | 10299 | table public.data: INSERT: id[integer]:3 data[text]:'3'
+ 0/0BA5A990 | 10299 | COMMIT 10299 (at 2017-05-10 12:07:21.272494-04)
 (3 rows)
 
 postgres=# -- Remember to destroy a slot you no longer need to stop it consuming
@@ -200,18 +200,18 @@ postgres=*# INSERT INTO data(data) VALUES('5');
 postgres=*# PREPARE TRANSACTION 'test_prepared1';
 
 postgres=# SELECT * FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL);
-    lsn    | xid |                          data
------------+-----+---------------------------------------------------------
- 0/1689DC0 | 529 | BEGIN 529
- 0/1689DC0 | 529 | table public.data: INSERT: id[integer]:3 data[text]:'5'
- 0/1689FC0 | 529 | PREPARE TRANSACTION 'test_prepared1', txid 529
+    lsn     | xid |                          data
+------------+-----+---------------------------------------------------------
+ 0/01689DC0 | 529 | BEGIN 529
+ 0/01689DC0 | 529 | table public.data: INSERT: id[integer]:3 data[text]:'5'
+ 0/01689FC0 | 529 | PREPARE TRANSACTION 'test_prepared1', txid 529
 (3 rows)
 
 postgres=# COMMIT PREPARED 'test_prepared1';
 postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NULL);
-    lsn    | xid |                    data
------------+-----+--------------------------------------------
- 0/168A060 | 529 | COMMIT PREPARED 'test_prepared1', txid 529
+    lsn     | xid |                    data
+------------+-----+--------------------------------------------
+ 0/0168A060 | 529 | COMMIT PREPARED 'test_prepared1', txid 529
 (4 row)
 
 postgres=#-- you can also rollback a prepared transaction
@@ -219,18 +219,18 @@ postgres=# BEGIN;
 postgres=*# INSERT INTO data(data) VALUES('6');
 postgres=*# PREPARE TRANSACTION 'test_prepared2';
 postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NULL);
-    lsn    | xid |                          data
------------+-----+---------------------------------------------------------
- 0/168A180 | 530 | BEGIN 530
- 0/168A1E8 | 530 | table public.data: INSERT: id[integer]:4 data[text]:'6'
- 0/168A430 | 530 | PREPARE TRANSACTION 'test_prepared2', txid 530
+    lsn     | xid |                          data
+------------+-----+---------------------------------------------------------
+ 0/0168A180 | 530 | BEGIN 530
+ 0/0168A1E8 | 530 | table public.data: INSERT: id[integer]:4 data[text]:'6'
+ 0/0168A430 | 530 | PREPARE TRANSACTION 'test_prepared2', txid 530
 (3 rows)
 
 postgres=# ROLLBACK PREPARED 'test_prepared2';
 postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NULL);
-    lsn    | xid |                     data
------------+-----+----------------------------------------------
- 0/168A4B8 | 530 | ROLLBACK PREPARED 'test_prepared2', txid 530
+    lsn     | xid |                     data
+------------+-----+----------------------------------------------
+ 0/0168A4B8 | 530 | ROLLBACK PREPARED 'test_prepared2', txid 530
 (1 row)
 </programlisting>
 </sect1>
@@ -431,7 +431,7 @@ postgres=# select * from pg_logical_slot_get_changes('regression_slot', NULL, NU
      cases, the following log message may appear:
 <programlisting>
      LOG:  could not synchronize replication slot "failover_slot"
-     DETAIL:  Synchronization could lead to data loss as the remote slot needs WAL at LSN 0/3003F28 and catalog xmin 754, but the standby has LSN 0/3003F28 and catalog xmin 756
+     DETAIL:  Synchronization could lead to data loss as the remote slot needs WAL at LSN 0/03003F28 and catalog xmin 754, but the standby has LSN 0/03003F28 and catalog xmin 756
 </programlisting>
      If the logical replication slot is actively used by a consumer, no
      manual intervention is needed; the slot will advance automatically,
diff --git a/doc/src/sgml/pageinspect.sgml b/doc/src/sgml/pageinspect.sgml
index 487c5d758ff..12873d17d7f 100644
--- a/doc/src/sgml/pageinspect.sgml
+++ b/doc/src/sgml/pageinspect.sgml
@@ -73,9 +73,9 @@
       passed as argument.  For example:
 <screen>
 test=# SELECT * FROM page_header(get_raw_page('pg_class', 0));
-    lsn    | checksum | flags  | lower | upper | special | pagesize | version | prune_xid
------------+----------+--------+-------+-------+---------+----------+---------+-----------
- 0/24A1B50 |        0 |      1 |   232 |   368 |    8192 |     8192 |       4 |         0
+    lsn     | checksum | flags  | lower | upper | special | pagesize | version | prune_xid
+------------+----------+--------+-------+-------+---------+----------+---------+-----------
+ 0/024A1B50 |        0 |      1 |   232 |   368 |    8192 |     8192 |       4 |         0
 </screen>
       The returned columns correspond to the fields in the
       <structname>PageHeaderData</structname> struct.
@@ -741,9 +741,9 @@ test=# SELECT first_tid, nbytes, tids[0:5] AS some_tids
       For example:
 <screen>
 test=# SELECT * FROM gist_page_opaque_info(get_raw_page('test_gist_idx', 2));
- lsn | nsn | rightlink | flags
------+-----+-----------+--------
- 0/1 | 0/0 |         1 | {leaf}
+    lsn     │    nsn     │ rightlink │ flags  
+────────────┼────────────┼───────────┼────────
+ 0/0B5FE088 │ 0/00000000 │         1 │ {leaf}
 (1 row)
 </screen>
      </para>
diff --git a/doc/src/sgml/pglogicalinspect.sgml b/doc/src/sgml/pglogicalinspect.sgml
index 4b111f96113..1c1a9d14e51 100644
--- a/doc/src/sgml/pglogicalinspect.sgml
+++ b/doc/src/sgml/pglogicalinspect.sgml
@@ -95,7 +95,7 @@ two_phase_at             | 0/40796AF8
 initial_xmin_horizon     | 0
 building_full_snapshot   | f
 in_slot_creation         | f
-last_serialized_snapshot | 0/0
+last_serialized_snapshot | 0/00000000
 next_phase_at            | 0
 committed_count          | 0
 committed_xip            |
@@ -114,7 +114,7 @@ two_phase_at             | 0/40796AF8
 initial_xmin_horizon     | 0
 building_full_snapshot   | f
 in_slot_creation         | f
-last_serialized_snapshot | 0/0
+last_serialized_snapshot | 0/00000000
 next_phase_at            | 0
 committed_count          | 0
 committed_xip            |
diff --git a/doc/src/sgml/pgwalinspect.sgml b/doc/src/sgml/pgwalinspect.sgml
index 3a8121c70f1..79c3ead40bc 100644
--- a/doc/src/sgml/pgwalinspect.sgml
+++ b/doc/src/sgml/pgwalinspect.sgml
@@ -73,9 +73,9 @@
 <screen>
 postgres=# SELECT * FROM pg_get_wal_record_info('0/E419E28');
 -[ RECORD 1 ]----+-------------------------------------------------
-start_lsn        | 0/E419E28
-end_lsn          | 0/E419E68
-prev_lsn         | 0/E419D78
+start_lsn        | 0/0E419E28
+end_lsn          | 0/0E419E68
+prev_lsn         | 0/0E419D78
 xid              | 0
 resource_manager | Heap2
 record_type      | VACUUM
@@ -146,9 +146,9 @@ block_ref        |
 <screen>
 postgres=# SELECT * FROM pg_get_wal_block_info('0/1230278', '0/12302B8');
 -[ RECORD 1 ]-----+-----------------------------------
-start_lsn         | 0/1230278
-end_lsn           | 0/12302B8
-prev_lsn          | 0/122FD40
+start_lsn         | 0/01230278
+end_lsn           | 0/012302B8
+prev_lsn          | 0/0122FD40
 block_id          | 0
 reltablespace     | 1663
 reldatabase       | 1
diff --git a/doc/src/sgml/test-decoding.sgml b/doc/src/sgml/test-decoding.sgml
index 5d1ae8f4f52..7d3d590471a 100644
--- a/doc/src/sgml/test-decoding.sgml
+++ b/doc/src/sgml/test-decoding.sgml
@@ -25,16 +25,16 @@
 
 <programlisting>
 postgres=# SELECT * FROM pg_logical_slot_get_changes('test_slot', NULL, NULL, 'include-xids', '0');
-   lsn     | xid |                       data
------------+-----+--------------------------------------------------
- 0/16D30F8 | 691 | BEGIN
- 0/16D32A0 | 691 | table public.data: INSERT: id[int4]:2 data[text]:'arg'
- 0/16D32A0 | 691 | table public.data: INSERT: id[int4]:3 data[text]:'demo'
- 0/16D32A0 | 691 | COMMIT
- 0/16D32D8 | 692 | BEGIN
- 0/16D3398 | 692 | table public.data: DELETE: id[int4]:2
- 0/16D3398 | 692 | table public.data: DELETE: id[int4]:3
- 0/16D3398 | 692 | COMMIT
+    lsn     | xid |                       data
+------------+-----+--------------------------------------------------
+ 0/016D30F8 | 691 | BEGIN
+ 0/016D32A0 | 691 | table public.data: INSERT: id[int4]:2 data[text]:'arg'
+ 0/016D32A0 | 691 | table public.data: INSERT: id[int4]:3 data[text]:'demo'
+ 0/016D32A0 | 691 | COMMIT
+ 0/016D32D8 | 692 | BEGIN
+ 0/016D3398 | 692 | table public.data: DELETE: id[int4]:2
+ 0/016D3398 | 692 | table public.data: DELETE: id[int4]:3
+ 0/016D3398 | 692 | COMMIT
 (8 rows)
 </programlisting>
  </para>
@@ -45,18 +45,18 @@ postgres=# SELECT * FROM pg_logical_slot_get_changes('test_slot', NULL, NULL, 'i
 
 <programlisting>
 postgres[33712]=#* SELECT * FROM pg_logical_slot_get_changes('test_slot', NULL, NULL, 'stream-changes', '1');
-    lsn    | xid |                       data
------------+-----+--------------------------------------------------
- 0/16B21F8 | 503 | opening a streamed block for transaction TXN 503
- 0/16B21F8 | 503 | streaming change for TXN 503
- 0/16B2300 | 503 | streaming change for TXN 503
- 0/16B2408 | 503 | streaming change for TXN 503
- 0/16BEBA0 | 503 | closing a streamed block for transaction TXN 503
- 0/16B21F8 | 503 | opening a streamed block for transaction TXN 503
- 0/16BECA8 | 503 | streaming change for TXN 503
- 0/16BEDB0 | 503 | streaming change for TXN 503
- 0/16BEEB8 | 503 | streaming change for TXN 503
- 0/16BEBA0 | 503 | closing a streamed block for transaction TXN 503
+    lsn     | xid |                       data
+------------+-----+--------------------------------------------------
+ 0/016B21F8 | 503 | opening a streamed block for transaction TXN 503
+ 0/016B21F8 | 503 | streaming change for TXN 503
+ 0/016B2300 | 503 | streaming change for TXN 503
+ 0/016B2408 | 503 | streaming change for TXN 503
+ 0/016BEBA0 | 503 | closing a streamed block for transaction TXN 503
+ 0/016B21F8 | 503 | opening a streamed block for transaction TXN 503
+ 0/016BECA8 | 503 | streaming change for TXN 503
+ 0/016BEDB0 | 503 | streaming change for TXN 503
+ 0/016BEEB8 | 503 | streaming change for TXN 503
+ 0/016BEBA0 | 503 | closing a streamed block for transaction TXN 503
 (10 rows)
 </programlisting>
  </para>