Functionality Added or Changed$$$Important Change: Added the mysql client --commands option; which enables or disables most mysql client commands.$$$$$$This option is enabled by default. To disable it; start the client with --commands=OFF or --skip-commands.$$$$$$For a complete list of all commands affected by this option; and additional information; see mysql Client Options. (WL #16949)$$$$$$References: See also: Bug #36416568; Bug #38066040.

Changes in MySQL 8.4.5 (2025-04-15; LTS Release)$$$Account Management Notes$$$$$$Audit Log Notes$$$$$$Compilation Notes$$$$$$SQL Function and Operator Notes$$$$$$INFORMATION_SCHEMA Notes$$$$$$Functionality Added or Changed$$$$$$Bugs Fixed$$$$$$Account Management Notes$$$It was possible in some cases to grant a user the EXECUTE privilege; but subsequently to be unable to revoke it from the same user. (Bug #37570206)$$$$$$Audit Log Notes$$$<COMMAND_CLASS> was not populated for <NAME>Execute</NAME>.$$$$$$For more information; see Logging Specific Event Classes. (Bug #36686351)$$$$$$Compilation Notes$$$Group Replication: The OpenSSL Engine interface is deprecated; and is no longer being included in OpenSSL v3 main packages by some Linux distributions; including Fedora.$$$$$$To avoid build issues; the usage of the OpenSSL Engine interface by the Group Communication System (GCS) is now restricted to OpenSSL versions previous to 1.1. (Bug #37475769)$$$$$$Linux: Use /usr/bin/gcc (GCC 14.2.1) when building the server on Oracle Linux 10. (Bug #37616148)$$$$$$Upgraded the bundled Curl library to version 8.12.1. (Bug #37633587)$$$$$$Abseil could not be built on FreeBSD. (Bug #37611924)$$$$$$The bundled version of opentelemetry-cpp was upgraded to version 1.19.0. (Bug #37506554)$$$$$$In order to use xxhash functions independently from the lz4 library (bundled or source); we compiled xxhash.c into our own binaries; which required using a great many CMake directives. Instead; we now build an interface library for xxhash; and link with that wherever such functions are used. (Bug #37417386)$$$$$$Use xxHash-0.8.2 from GitHub rather than the version bundled with lz4. (Bug #37387318)

Changes in MySQL 8.4.5 (2025-04-15; LTS Release)$$$Account Management Notes$$$$$$Audit Log Notes$$$$$$Compilation Notes$$$$$$SQL Function and Operator Notes$$$$$$INFORMATION_SCHEMA Notes$$$$$$Functionality Added or Changed$$$$$$Bugs Fixed$$$$$$Account Management Notes$$$It was possible in some cases to grant a user the EXECUTE privilege; but subsequently to be unable to revoke it from the same user. (Bug #37570206)$$$$$$Audit Log Notes$$$<COMMAND_CLASS> was not populated for <NAME>Execute</NAME>.$$$$$$For more information; see Logging Specific Event Classes. (Bug #36686351)$$$$$$Compilation Notes$$$Group Replication: The OpenSSL Engine interface is deprecated; and is no longer being included in OpenSSL v3 main packages by some Linux distributions; including Fedora.$$$$$$To avoid build issues; the usage of the OpenSSL Engine interface by the Group Communication System (GCS) is now restricted to OpenSSL versions previous to 1.1. (Bug #37475769)$$$$$$Linux: Use /usr/bin/gcc (GCC 14.2.1) when building the server on Oracle Linux 10. (Bug #37616148)$$$$$$Upgraded the bundled Curl library to version 8.12.1. (Bug #37633587)$$$$$$Abseil could not be built on FreeBSD. (Bug #37611924)$$$$$$The bundled version of opentelemetry-cpp was upgraded to version 1.19.0. (Bug #37506554)$$$$$$In order to use xxhash functions independently from the lz4 library (bundled or source); we compiled xxhash.c into our own binaries; which required using a great many CMake directives. Instead; we now build an interface library for xxhash; and link with that wherever such functions are used. (Bug #37417386)$$$$$$Use xxHash-0.8.2 from GitHub rather than the version bundled with lz4. (Bug #37387318)

Changes in MySQL 8.4.4 (2025-01-21; LTS Release)$$$Bugs Fixed$$$Incompatible Change: Corruption occurred in a spatial index when an update of a geometry with a minimal change in the minimum bounding rectangle (MBR) was followed by a delete operation.$$$$$$When upgrading to this release; it is recommended that you drop any spatial indexes beforehand; then re-create them after the upgrade is complete. Alternatively; you can drop and re-create such indexes immediately following the upgrade; but before making use of any of the tables in which they occur. You should also be aware that downgrading to any previous version reintroduces the original problem described previously.$$$$$$For more information; see Creating Spatial Indexes. (Bug #36452528)$$$$$$InnoDB: Concurrently truncating a table while querying the Performance Schema sometimes cause MySQL to halt unexpectedly. (Bug #37271715)$$$$$$InnoDB: It was possible for an ALTER TABLE operation using the INPLACE algorithm on a table containing both a spatial index and an auto-increment column to cause corruption or; in debug builds; to trigger a debug assert. This was due to the auto-increment column value being overwritten in the old records of the spatial index while the new record was prepared. (Bug #37189985)$$$$$$InnoDB: Certain IO buffer serializations triggered an assertion in debug builds that caused the system to hang. (Bug #37139618)$$$$$$InnoDB: Improved InnoDB start up time. (Bug #36880863)$$$$$$References: This issue is a regression of: Bug #36808732.$$$$$$InnoDB: An assertion failure was raised when creating a FULLTEXT index on a table with an FTS_DOC_ID value greater than 4294967295. (Bug #36879147)$$$$$$References: See also: Bug #37387224.$$$$$$InnoDB: Dropping a primary key; and then adding a new AUTO_INCREMENT column as a primary key in descending order using the INPLACE algorithm failed.$$$$$$Our thanks to Shaohua Wang and the team at Alibaba for the contribution. (Bug #36658450)

Changes in MySQL 8.4.3 (2024-10-15; LTS Release)$$$$$$Bugs Fixed$$$Performance; InnoDB: Several functions internal to InnoDB; which were defined as inline in MySQL 8.0.28; were found to be no longer inline in MySQL 8.0.33; due in part to refactoring which accompanied improvements made in MySQL 8.0.30 to improve the InnoDB adaptive hash index. This had an adverse effect on queries using joins on InnoDB tables. (Bug #111538; Bug #35531293)$$$$$$References: This issue is a regression of: Bug #81814; Bug #16739204; Bug #23584861.$$$$$$InnoDB: InnoDB did not allow updating a REDUNDANT table column that was altered with NULL as the default value using the INSTANT algorithm. Instead; MySQL unexpectedly halted. (Bug #36840107)$$$$$$InnoDB: When redo log capacity was reduced with log_files_truncate; under rare circumstances the file.end_lsn equaled log_sys->write_lsn thus disallowing future redo log writes. (Bug #36730830)$$$$$$InnoDB: It was possible for the MySQL server to halt unexpectedly when executing a DELETE or UPDATE statement after a column was dropped using the INSTANT algorithm. (Bug #36723117)$$$$$$InnoDB: FTS index optimization would sometimes not function correctly with tokens equal in collation order but different in terms of bytes. (Bug #36652127)$$$$$$InnoDB: Replaced std::this_thread::sleep_for(std::chrono::seconds(0)) usage with std::this_thread::yield() to prevent it from being optimized out while compiled. (Bug #36522343)$$$$$$InnoDB: The upgrade process unexpectedly halted when the database contained a full-text index created in MySQL 5.7 with a user-created FTS_DOC_ID column as the primary key.$$$$$$Our thanks to Huaxiong Song and the team at Alibaba for contributing to this fix. (Bug #36496164)$$$$$$InnoDB: Disabled the optimizer for indexes with range conditions on multiple-value virtual columns. (Bug #36341532)$$$$$$InnoDB: Redesigned the performance schema data_locks and data_lock_waits tables so that querying them does not require an exclusive global mutex on the transaction or lock system. It now iterates over buckets of hash tables that hold the locks to only latch the actively processed shard; when previously it iterated over the transactions. This also improves the iteration logic complexity in terms of speed and memory to decrease the impact of these queries on the rest of the system.$$$$$$Note that the query result might show an incomplete list of transaction locks if it committed; started; or otherwise changed the set of owned locks in-between visiting two buckets. This differs from previous behavior which always showed a consistent snapshot of locks held by individual transactions; although two different transactions could have been presented at different moments. In other words; the new approach gives a consistent view of a single wait queue to show conflicting locks with a waiting lock because they are always in the same bucket; while the old approach could miss some of them because they belonged to other transactions. The old approach would always show all the other locks held by a reported transaction but could miss locks of other transactions even if they were conflicting. (Bug #36302624)$$$$$$InnoDB: On Windows; fixed a doublewrite buffer regression that slowed file access; and refactored FILE_FLAG_OVERLAPPED flag usage for opening files. (Bug #36259487)$$$$$$InnoDB: A schema mismatch was possible when a table was imported with a different sql_mode than when it was created; because strict mode influences the number of nullable columns in a tables secondary index. Now the secondary index trees are also checked for corruption after a tablespace is imported. (Bug #35799038)$$$$$$InnoDB: Given a table with an FTS index; when its tablespace is discarded the corresponding FTS tables are also dropped. When performing an operation that cleared out these tables; the code incorrectly assumed that the FTS tables must also exist if the FTS indexes were present in the table metadata. (Bug #35343458)$$$$$$InnoDB: An uninitialized buffer

Changes in MySQL 8.4.2 (2024-07-23; LTS Release)$$$Bugs Fixed$$$InnoDB: In some cases; following the creation of a very large number of tables (8001 or more); the server could not be restarted successfully. (Bug #36808732)$$$$$$References: This issue is a regression of: Bug #33398681.$$$$$$InnoDB: Improved tablespace file scan performance at startup. (Bug #110402; Bug #35200385)$$$$$$Group Replication: Running a CREATE TABLE ... SELECT statement on a source coming from an asynchronous channel to Group Replication led to errors on the replica. (Bug #36784284)$$$$$$