MySQL Bugs: #120353: InnoDB crashes with assertion failure (ut_dbg_assertion_failed) when creating index with ALGORITHM COPY on table with F

Bug #120353	InnoDB crashes with assertion failure (ut_dbg_assertion_failed) when creating index with ALGORITHM COPY on table with F
Submitted:	27 Apr 11:55	Modified:	29 Apr 11:43
Reporter:	Jason Tang	Email Updates:
Status:	Can't repeat	Impact on me:	None
Category:	MySQL Server: InnoDB storage engine	Severity:	S2 (Serious)
Version:	<=8.0.42-debug	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
Executing a standard sequence of DDL statements (create database → create table with FLOAT column STORAGE DISK and unique constraint → create composite unique index → create secondary index with VISIBLE ALGORITHM COPY) causes the MySQL server to crash immediately with an InnoDB assertion failure.

The crash occurs in the InnoDB index creation function btr_create(), triggering a debug assertion failure (ut_dbg_assertion_failed). The server cannot handle the DDL combination gracefully and aborts directly.

How to repeat:
-- 1. Initialize database
DROP DATABASE IF EXISTS fuzzDatabase1;
CREATE DATABASE fuzzDatabase1;
USE fuzzDatabase1;

-- 2. Modify InnoDB global variable (no impact on crash, included in original test case)
SET GLOBAL innodb_redo_log_capacity = 137438953472;

-- 3. Create table with FLOAT column: STORAGE DISK + UNIQUE NULL
CREATE TABLE IF NOT EXISTS t0(
    c0 DECIMAL, 
    c1 FLOAT STORAGE DISK UNIQUE NULL 
);

-- 4. Create composite unique index (DECIMAL + FLOAT columns)
CREATE UNIQUE INDEX i0 ON t0(c0 ASC, c1);

-- 5. Useless update (no impact on crash)
UPDATE t0 SET c0=DEFAULT;

-- 6. CRASH TRIGGER: Create BTREE index with VISIBLE + ALGORITHM COPY
CREATE INDEX i1 USING BTREE ON t0(c0, c1) VISIBLE ALGORITHM COPY;

Please upload your mysql error log and my.cnf.  I couldn't reproduce this on 8.0.46-debug.

mysql> CREATE DATABASE fuzzDatabase1;
Query OK, 1 row affected (0.01 sec)

mysql> USE fuzzDatabase1;
Database changed
mysql> CREATE TABLE IF NOT EXISTS t0(
    ->     c0 DECIMAL,
    ->     c1 FLOAT STORAGE DISK UNIQUE NULL
    -> );
Query OK, 0 rows affected (0.07 sec)

mysql> CREATE UNIQUE INDEX i0 ON t0(c0 ASC, c1);
Query OK, 0 rows affected (0.09 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> UPDATE t0 SET c0=DEFAULT;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0  Changed: 0  Warnings: 0

mysql> CREATE INDEX i1 USING BTREE ON t0(c0, c1) VISIBLE ALGORITHM COPY;
Query OK, 0 rows affected (0.16 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> select version();
+-------------------------+
| version()               |
+-------------------------+
| 8.0.46-commercial-debug |
+-------------------------+
1 row in set (0.00 sec)

-- 
Shane, MySQL Senior Principal Technical Support Engineer
Oracle Corporation
http://dev.mysql.com/

InnoDB: We intentionally generate a memory trap.
InnoDB: Submit a detailed bug report to http://bugs.mysql.com.
InnoDB: If you get repeated assertion failures or crashes, even
InnoDB: immediately after the mysqld startup, there may be
InnoDB: corruption in the InnoDB tablespace. Please refer to
InnoDB: http://dev.mysql.com/doc/refman/8.0/en/forcing-innodb-recovery.html
InnoDB: about forcing recovery.
2026-04-27T11:46:22Z UTC - mysqld got signal 6 ;
Most likely, you have hit a bug, but this error can also be caused by malfunctioning hardware.
BuildID[sha1]=74c66055f3de3ce92689b61f26f34703359b2316
Thread pointer: 0x7f38c8001050
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 7f39387f79b8 thread_stack 0x100000
/usr/local/mysql/bin/mysqld(my_print_stacktrace(unsigned char const*, unsigned long)+0x4c) [0x55efe32ededc]
/usr/local/mysql/bin/mysqld(print_fatal_signal(int)+0x398) [0x55efe11f72e8]
/usr/local/mysql/bin/mysqld(my_server_abort()+0x10d) [0x55efe11f769d]
/usr/local/mysql/bin/mysqld(my_abort()+0xa) [0x55efe32dd35a]
/usr/local/mysql/bin/mysqld(ut_dbg_assertion_failed(char const*, char const*, unsigned long)+0x2c6) [0x55efe384c9c6]
/usr/local/mysql/bin/mysqld(+0x3df605d) [0x55efe38bd05d]
/usr/local/mysql/bin/mysqld(btr_create(unsigned long, unsigned int, unsigned long, dict_index_t*, mtr_t*)+0x76a) [0x55efe38bca5a]
/usr/local/mysql/bin/mysqld(dict_create_index_tree_in_mem(dict_index_t*, trx_t*)+0x29c) [0x55efe3a3acac]
/usr/local/mysql/bin/mysqld(row_create_index_for_mysql(dict_index_t*, trx_t*, unsigned long const*, dict_table_t*)+0x75c) [0x55efe36a1a3c]
/usr/local/mysql/bin/mysqld(create_index(trx_t*, TABLE const*, unsigned int, char const*, unsigned int, dd::Table const*)+0x1118) [0x55efe33953d8]
/usr/local/mysql/bin/mysqld(create_table_info_t::create_table(dd::Table const*, dd::Table const*)+0x132b) [0x55efe338fe5b]
/usr/local/mysql/bin/mysqld(int innobase_basic_ddl::create_impl<dd::Table>(THD*, char const*, TABLE*, HA_CREATE_INFO*, dd::Table*, bool, bool, bool, unsigned int, unsigned int, dd::Table const*)+0x26c) [0x55efe33985dc]
/usr/local/mysql/bin/mysqld(ha_innobase::create(char const*, TABLE*, HA_CREATE_INFO*, dd::Table*)+0x218) [0x55efe33a4398]
/usr/local/mysql/bin/mysqld(ha_create_table(THD*, char const*, char const*, char const*, HA_CREATE_INFO*, bool, bool, dd::Table*)+0x82f) [0x55efe14561bf]
/usr/local/mysql/bin/mysqld(mysql_alter_table(THD*, char const*, char const*, HA_CREATE_INFO*, Table_ref*, Alter_info*)+0x4661) [0x55efe102c071]
/usr/local/mysql/bin/mysqld(Sql_cmd_create_or_drop_index_base::execute(THD*)+0x2dd) [0x55efe199677d]
/usr/local/mysql/bin/mysqld(mysql_execute_command(THD*, bool)+0x5fbb) [0x55efe0ec29cb]
/usr/local/mysql/bin/mysqld(dispatch_sql_command(THD*, Parser_state*)+0xfa8) [0x55efe0eb90d8]
/usr/local/mysql/bin/mysqld(dispatch_command(THD*, COM_DATA const*, enum_server_command)+0x4792) [0x55efe0eb3d32]
/usr/local/mysql/bin/mysqld(do_command(THD*)+0x9de) [0x55efe0eb6a8e]
/usr/local/mysql/bin/mysqld(+0x170b554) [0x55efe11d2554]
/usr/local/mysql/bin/mysqld(+0x48e64dc) [0x55efe43ad4dc]
/lib/x86_64-linux-gnu/libc.so.6(+0x94ac3) [0x7f3986c60ac3]
/lib/x86_64-linux-gnu/libc.so.6(+0x1268d0) [0x7f3986cf28d0]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (7f38c8202fc0): CREATE INDEX i1 USING BTREE ON t0(c0, c1) VISIBLE ALGORITHM COPY
Connection ID (thread ID): 8
Status: NOT_KILLED

POC:

DROP DATABASE IF EXISTS fuzzDatabase1;
CREATE DATABASE fuzzDatabase1;
USE fuzzDatabase1;
SET GLOBAL innodb_redo_log_capacity = 137438953472;
CREATE TABLE IF NOT EXISTS t0(c0 DECIMAL, c1 FLOAT  STORAGE DISK UNIQUE NULL ) ;
CREATE UNIQUE INDEX i0 ON t0(c0 ASC, c1);
UPDATE t0 SET c0=DEFAULT;
CREATE INDEX i1 USING BTREE ON t0(c0, c1) VISIBLE ALGORITHM COPY;

Hello!

I cannot repeat this on linux on 8.0.45-debug either.

However, I notice you've changed the version:

-Version:          8.0.45+
+Version:          <=8.0.42-debug

Still not able to reproduce this on 8.0.42-debug.

$ mysql -uroot -h127.0.0.1 -P3333
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 8.0.42-debug (Built on 24 May 2025,  with gcc (GCC) 11.5.0 20240719 (Red Hat 11.5.0-5.0.1))

Copyright (c) 2000, 2025, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>
CREATE TABLE IF NOT EXISTS t0(c0 DECIMAL, c1 FLOAT  STORAGE DISK UNIQUE NULL ) ;
mysql> DROP DATABASE IF EXISTS fuzzDatabase1;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> CREATE DATABASE fuzzDatabase1;
Query OK, 1 row affected (0.00 sec)

mysql> USE fuzzDatabase1;
Database changed
mysql> SET GLOBAL innodb_redo_log_capacity = 137438953472;
Query OK, 0 rows affected (0.02 sec)

mysql> CREATE TABLE IF NOT EXISTS t0(c0 DECIMAL, c1 FLOAT  STORAGE DISK UNIQUE NULL ) ;
Query OK, 0 rows affected (0.06 sec)

mysql> CREATE UNIQUE INDEX i0 ON t0(c0 ASC, c1);
Query OK, 0 rows affected (0.08 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> UPDATE t0 SET c0=DEFAULT;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0  Changed: 0  Warnings: 0

mysql> CREATE INDEX i1 USING BTREE ON t0(c0, c1) VISIBLE ALGORITHM COPY;
Query OK, 0 rows affected (0.20 sec)
Records: 0  Duplicates: 0  Warnings: 0

Older versions don't get fixed.  Suggest you please try 8.4.9 or newer.