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Subject: BUG #19555: TRAP: failed Assert (ent->cmin ==
 change->data.tuplecid.cmin) on logical replication
To: pgsql-bugs@lists.postgresql.org
From: PG Bug reporting form <noreply@postgresql.org>
Cc: a.kozhemyakin@postgrespro.ru
Reply-To: a.kozhemyakin@postgrespro.ru, pgsql-bugs@lists.postgresql.org
Date: Fri, 17 Jul 2026 03:55:20 +0000
Message-ID: <19555-3c700f40a13045cd@postgresql.org>
Auto-Submitted: auto-generated
Archived-At: 
 <https://www.postgresql.org/message-id/19555-3c700f40a13045cd%40postgresql.org>
Precedence: bulk

The following bug has been logged on the website:

Bug reference:      19555
Logged by:          Alexander Kozhemyakin
Email address:      a.kozhemyakin@postgrespro.ru
PostgreSQL version: 19beta2
Operating system:   ubuntu 26.04
Description:       =20

Hi,

We've encountered an assertion failure in ReorderBufferBuildTupleCidHash
when
processing DDL operations within subtransactions. The issue reproduces on
REL_19_STABLE (commit 64542957b44).

reproduce script:

psql -c "CREATE TABLE CHAR_TBL(f1 char(4));"
psql <<EOF
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot',
'test_decoding');
CREATE TABLE xact_test(data text);
INSERT INTO xact_test VALUES ('before-test');
EOF

psql -c "create type complex as (r float8, i float8);"
psql -c "CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT
'Unspecified');"
psql -c "create table copydml_test (id serial, t text);"

psql <<EOF
CREATE TABLE stream_test(data text);
INSERT INTO stream_test SELECT repeat('a', 2000) || g.i FROM
generate_series(1, 1) g(i);
TRUNCATE table stream_test;
EOF

psql -c "checkpoint;"

psql <<EOF
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL,
'include-xids', '0', 'skip-empty-xacts', '1');
CREATE TABLE tr_sub_ddl(data int);
BEGIN;
SAVEPOINT a;
ALTER TABLE tr_sub_ddl ALTER COLUMN data TYPE text;
ROLLBACK TO SAVEPOINT a;
ALTER TABLE tr_sub_ddl ALTER COLUMN data TYPE bigint;
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL,
'include-xids', '0', 'skip-empty-xacts', '1');
EOF

backtrace
(gdb) bt
#0  __pthread_kill_implementation (threadid=3D<optimized out>, signo=3D6,
no_tid=3D0) at ./nptl/pthread_kill.c:44
#1  __pthread_kill_internal (threadid=3D<optimized out>, signo=3D6) at
./nptl/pthread_kill.c:89
#2  __GI___pthread_kill (threadid=3D<optimized out>, signo=3Dsigno@entry=3D=
6) at
./nptl/pthread_kill.c:100
#3  0x00007bfbec845b7e in __GI_raise (sig=3Dsig@entry=3D6) at
../sysdeps/posix/raise.c:26
#4  0x00007bfbec8288ec in __GI_abort () at ./stdlib/abort.c:77
#5  0x000057ceaf77ce1c in ExceptionalCondition
(conditionName=3DconditionName@entry=3D0x57ceaf851c28 "ent->cmin =3D=3D
change->data.tuplecid.cmin",
    fileName=3DfileName@entry=3D0x57ceaf8516c0
"/pgpro/postgres/src/backend/replication/logical/reorderbuffer.c",
lineNumber=3DlineNumber@entry=3D1890) at
/pgpro/postgres/src/backend/utils/error/assert.c:65
#6  0x000057ceaf56e58b in ReorderBufferBuildTupleCidHash (rb=3D0x57ceb31da6=
f0,
txn=3D0x57ceb31ee6d0) at
/pgpro/postgres/src/backend/replication/logical/reorderbuffer.c:1890
#7  ReorderBufferProcessTXN (rb=3D0x57ceb31da6f0, txn=3D0x57ceb31ee6d0,
commit_lsn=3D25223904, snapshot_now=3D<optimized out>,
command_id=3Dcommand_id@entry=3D0, streaming=3Dstreaming@entry=3Dfalse)
    at /pgpro/postgres/src/backend/replication/logical/reorderbuffer.c:2220
#8  0x000057ceaf56f61c in ReorderBufferReplay (txn=3D<optimized out>,
rb=3D<optimized out>, commit_lsn=3D<optimized out>, end_lsn=3D<optimized ou=
t>,
commit_time=3D<optimized out>, origin_id=3D<optimized out>, origin_lsn=3D0,
    xid=3D<optimized out>) at
/pgpro/postgres/src/backend/replication/logical/reorderbuffer.c:2870
#9  0x000057ceaf570375 in ReorderBufferCommit (rb=3D<optimized out>,
xid=3D<optimized out>, commit_lsn=3D<optimized out>, end_lsn=3D<optimized o=
ut>,
commit_time=3D<optimized out>, origin_id=3D<optimized out>,
origin_lsn=3D<optimized out>)
    at /pgpro/postgres/src/backend/replication/logical/reorderbuffer.c:2894
#10 0x000057ceaf55db32 in DecodeCommit (ctx=3D0x57ceb31d66d0,
buf=3D0x7ffe6ad14500, parsed=3D0x7ffe6ad14370, xid=3D702, two_phase=3Dfalse=
) at
/pgpro/postgres/src/backend/replication/logical/decode.c:755
#11 xact_decode (ctx=3D0x57ceb31d66d0, buf=3D0x7ffe6ad14500) at
/pgpro/postgres/src/backend/replication/logical/decode.c:254
#12 0x000057ceaf55d473 in LogicalDecodingProcessRecord
(ctx=3Dctx@entry=3D0x57ceb31d66d0, record=3D0x57ceb31d6af8) at
/pgpro/postgres/src/backend/replication/logical/decode.c:117
#13 0x000057ceaf564d37 in pg_logical_slot_get_changes_guts
(fcinfo=3D0x57ceb31c6660, confirm=3Dconfirm@entry=3Dtrue,
binary=3Dbinary@entry=3Dfalse) at
/pgpro/postgres/src/backend/replication/logical/logicalfuncs.c:267
#14 0x000057ceaf564ec4 in pg_logical_slot_get_changes (fcinfo=3D<optimized
out>) at /pgpro/postgres/src/backend/replication/logical/logicalfuncs.c:336
#15 0x000057ceaf3f3bcd in ExecMakeTableFunctionResult
(setexpr=3D0x57ceb31bebd8, econtext=3D0x57ceb31bea28, argContext=3D<optimiz=
ed
out>, expectedDesc=3D0x57ceb31d8618, randomAccess=3Dfalse)
    at /pgpro/postgres/src/backend/executor/execSRF.c:235
#16 0x000057ceaf408c7d in FunctionNext (node=3Dnode@entry=3D0x57ceb31be818)=
 at
/pgpro/postgres/src/backend/executor/nodeFunctionscan.c:95
#17 0x000057ceaf3f44ac in ExecScanFetch (node=3D<optimized out>,
epqstate=3D<optimized out>, accessMtd=3D<optimized out>, recheckMtd=3D<opti=
mized
out>) at /pgpro/postgres/src/include/executor/execScan.h:135
#18 ExecScanExtended (node=3D<optimized out>, accessMtd=3D0x57ceaf408950
<FunctionNext>, recheckMtd=3D0x57ceaf408940 <FunctionRecheck>, epqstate=3D0=
x0,
qual=3D0x0, projInfo=3D0x57ceb31d8c58)
    at /pgpro/postgres/src/include/executor/execScan.h:196
#19 ExecScan (node=3D0x57ceb31be818, accessMtd=3D0x57ceaf408950 <FunctionNe=
xt>,
recheckMtd=3D0x57ceaf408940 <FunctionRecheck>) at
/pgpro/postgres/src/backend/executor/execScan.c:59
#20 0x000057ceaf3e852b in ExecProcNode (node=3D0x57ceb31be818) at
/pgpro/postgres/src/include/executor/executor.h:327
#21 ExecutePlan (queryDesc=3D0x57ceb319b2e0, operation=3DCMD_SELECT,
sendTuples=3Dtrue, numberTuples=3D0, direction=3D<optimized out>,
dest=3D0x57ceb31c0cc8) at /pgpro/postgres/src/backend/executor/execMain.c:1=
745
#22 standard_ExecutorRun (queryDesc=3D0x57ceb319b2e0, direction=3D<optimized
out>, count=3D0) at /pgpro/postgres/src/backend/executor/execMain.c:377
#23 0x000057ceaf60bc98 in PortalRunSelect
(portal=3Dportal@entry=3D0x57ceb314ed40, forward=3Dforward@entry=3Dtrue, co=
unt=3D0,
count@entry=3D9223372036854775807, dest=3Ddest@entry=3D0x57ceb31c0cc8)
    at /pgpro/postgres/src/backend/tcop/pquery.c:917
#24 0x000057ceaf60d35e in PortalRun (portal=3Dportal@entry=3D0x57ceb314ed40,
count=3Dcount@entry=3D9223372036854775807, isTopLevel=3DisTopLevel@entry=3D=
true,
dest=3Ddest@entry=3D0x57ceb31c0cc8, altdest=3Daltdest@entry=3D0x57ceb31c0cc=
8,
    qc=3Dqc@entry=3D0x7ffe6ad14b10) at
/pgpro/postgres/src/backend/tcop/pquery.c:761
#25 0x000057ceaf608e5a in exec_simple_query (query_string=3D0x57ceb30a0220
"SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL,
'include-xids', '0', 'skip-empty-xacts', '1');")
    at /pgpro/postgres/src/backend/tcop/postgres.c:1290
#26 0x000057ceaf60aa5d in PostgresMain (dbname=3D<optimized out>,
username=3D<optimized out>) at
/pgpro/postgres/src/backend/tcop/postgres.c:4856
#27 0x000057ceaf604a03 in BackendMain (startup_data=3D<optimized out>,
startup_data_len=3D<optimized out>) at
/pgpro/postgres/src/backend/tcop/backend_startup.c:124
#28 0x000057ceaf53f461 in postmaster_child_launch (child_type=3D<optimized
out>, child_slot=3D1, startup_data=3Dstartup_data@entry=3D0x7ffe6ad14fe0,
startup_data_len=3Dstartup_data_len@entry=3D24,
    client_sock=3Dclient_sock@entry=3D0x7ffe6ad15000) at
/pgpro/postgres/src/backend/postmaster/launch_backend.c:268
#29 0x000057ceaf543184 in BackendStartup (client_sock=3D0x7ffe6ad15000) at
/pgpro/postgres/src/backend/postmaster/postmaster.c:3627
#30 ServerLoop () at
/pgpro/postgres/src/backend/postmaster/postmaster.c:1728
#31 0x000057ceaf544e15 in PostmasterMain (argc=3Dargc@entry=3D3,
argv=3Dargv@entry=3D0x57ceb3047570) at
/pgpro/postgres/src/backend/postmaster/postmaster.c:1415
#32 0x000057ceaf1ceb2e in main (argc=3D3, argv=3D0x57ceb3047570) at
/pgpro/postgres/src/backend/main/main.c:231