Incompatible Change

Backward-incompatible changes in MySQL 5.0 and up

Tabulated by Artful Software Development

Version-to-version incompatibilities that can break existing SQL code and replication setups.

Versions	Url	Incompatible changes
5.0	http://dev.mysql.com/doc/refman/5.0/en/reserved-words.html	New reserved words in MySQL 5.0
5.0.1	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-1.html	C API change: `mysql_shutdown()` now requires a second argument.
5.0.2	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-2.html	Precedence of NOT operator, revert to previous behaviour wuth new `HIGH_NOT_PRECEDENCE` SQL mode
		`SHOW STATUS` now shows Session status variables, `SHOW GLOBAL STATUS` shows Global variables
5.0.3	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-3.html	C API `ER_WARN_DATA_TRUNCATED` warning symbol renamed to `WARN_DATA_TRUNCATED`.
		`DECIMAL` and `NUMERIC` data types handled with fixed-point library (Precision Math)
5.0.6	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-6.html	`LOAD DATA INFILE`, `SELECT ... INTO OUTFILE`: columns are read and written with field width wide enough to hold all values
		MyISAM & InnoDB Decimal columns incompatible with those created with 5.0.3 or 5.0.5
5.0.8	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-8.html	Format of result of conversion by `DATETIME+0` used to be `YYYYMMDDHHMMSS` format, now `YYYYMMDDHHMMSS.000000`
5.0.10	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-10.html	Trigger names unique in database namespace rather than table namespace
5.0.12	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-12.html	Joins upgraded to SQL:2003 standard, breaking some comma-join queries written for previous versions. See "Join Processing Changes in MySQL 5.0.12" in http://dev.mysql.com/doc/refman/5.0/en/join.html
5.0.13	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-13.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-15.html	InnoDB lock wait timeout caused roll back of entire current transaction, now only the most recent SQL statement.
5.0.14	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-15.html	Pad value for Binary columns changed from space to 0x00
5.0.15	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-15.html	Char() now returns a Binary string, accepts a USING charset argument, and breaks arguments > 255 into multiple result bytes, eg Char(65536) means Char(1,0,0) (but the mysql client interprets it incorrectly)
5.0.19	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-19.html	InnoDB now includes trailing spaces when comparing [Var]Binary column values.
5.0.19 5.1.7	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-19.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-7.html	New mysql_upgrade progam to check all tables and if necessary update them for backward incompatibility, and new Check Table For Upgrade option
5.0.23 5.1.12	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-23.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-12.html	Grant \| Revoke ... On * requires a default database, throws an error if there is not
5.0.24a 5.1.12	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-24a.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-12.html	5.0.24 introduced an application binary interface incompatibility, which 5.0.24a reverts.
5.0.27	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-27.html	5.0.26 introduced an application binary interface incompatibility, which 5.0.27 and Enterprise 5.0.28 revert.
5.0.30sp1	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-30sp1.html	In 5.0.30sp1 and 5.0.32 Enteprise, `--innodb_rollback_on_timeout` emulates pre-5.0.14 behaviour in causing InnoDB to abort and roll back the entire transaction on a transaction timeout
5.0.33	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-33.html	System variable `prepared_stmt_count` changed to global status variable `Prepared_stmt_count` (see `SHOW GLOBAL STATUS`).
5.0.36 5.1.15	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-36.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-15.html	Commas in `ENUM` column values are no longer mapped internally to `0xff`, so tables with true `0xff` values must be dumped with a pre-5.0.36 MySQL version, then reloaded with a 5.0.36 or later MySQL version.
5.0.37 5.1.15	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-37.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-15.html	Cluster configuration parameter `LockPagesInMainMemory` changes type and possible values. See `LockPagesInMainMemory`
		`DATE_FORMAT()` returns string using `character_set_connection` and `collation_connection` rather than a binary string to support day and month names with non-ASCII characters.
5.0.45	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-45.html	`INSERT DELAYED` statements not supported for, and no longer corrupts `MERGE` tables,
5.0.45 5.1.18	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-45.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-18.html	Date-DateTime comparison now coerces time portion of Date to 00:00:00 rather than ignoring it or treating the values as strings. For backward compatibility use Cast(datetimeval, Date)
5.0.45 5.1.20	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-45.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-20.html	Views invoking stored functions and created by 5.0.40 through 5.0.43 or 5.1.18-5.1.19 must be dropped and recreated
		Mysqldump `--delete-master-logs` option deleted log files before success is known. Now flushes logs, does the dump, then purges the logs, so log numbering differs from pre-5.0.42.
		Group_Concat() query with Order By or Distinct clause could redisplay results from previous queries. The fix to this may cause truncation, in which case a warning is issued.
5.0.51	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-51.html	Select statements containing unclosed `/*` now elicit syntax errors, may affect query parsing in stored procedures
5.0.52	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-52.html	In Delete commands, alias declarations may be declared only in table references
		Failing to declare collations may affect indexing
		If Sql Mode includes Only Full Group By, reject queries invoking Having without Group By
		Ensure that alias names in Views follow column name rules
		Coalesce(), If(), Ifnull(), Least(), Greatest(), Case, Str_To_Date() now return correct result types
5.0.67	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-67.html	Changes in handling of incompatible .frm files
5.0.67 5.1.24	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-67.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-24.html	Frac_Second deprecated; with anything other than Timestampadd() or Timestampdiff() produces syntax error.
5.0.67 5.1.26	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-67.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-26.html	Federated engine disabled by default in shipped example .cnf files
5.0.75 5.1.28	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-75.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-28.html	Changes to initialization code in libmysql.dll
		Status variable Innodb_buffer_pool_pages_latched shown only if UNIV_DEBUG is defined at MySQL build time
5.0.77 5.1.29	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-77.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-29.html	Lose unused database directory arc folders for Views
5.0.87	http://dev.mysql.com/doc/refman/5.0/en/news-5-0-87.html http://dev.mysql.com/doc/refman/5.1/en/news-5-1-40.html http://dev.mysql.com/doc/refman/5.5/en/news-5-5-0.html	Supplied binary-configure script no longer starts and configures MySQL with --help command-line option.
5.1	http://dev.mysql.com/doc/refman/5.1/en/reserved-words.html	New reserved words in MySQL 5.1
5.1.3	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-3.html	New plugin system
		Renamed `table_cache` system variable to `table_open_cache`
5.1.7	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-7.html	C API mysql_stmt_attr_get() function now returns boolean rather than unsigned int for STMT_ATTR_UPDATE_MAX_LENGTH.
		Changes in partition naming rules
		Type=... no longer accepted as synonym for Engine=... in Create Table
5.1.8	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-8.html	`cluster_replication` database renamed to `cluster`
		Changes in semantics for Alter Table for partitions
5.1.11	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-11.html	Changes in Event scheduler and information_schema.events
5.1.12	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-12.html	Cluster: allow different fragments to use different LCPs during restarts, allow access to information_schema.files from all engines
		Support for Berkeley DB (BDB) dropped
		Changes in partitioning syntax, fulltext parser plugin interface, utf8 fulltext whitespace handling
		Events now in database namespaces, not user namespaces
		Changes in sql_mode=IGNORE_SPACE
		System variable innodb_buffer_pool_awe_mem_mb system removed
5.1.14	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-14.html	Cluster system table changes
		System variable prepared_stmt_count changed to global status variable named Prepared_stmt_count
		Creating a UDF named the same as a built-in function generates an error, and creating a stored function with the same name as a built-in function generates a warning.
5.1.15	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-15.html	Changes to effects of enabling `read_only` system variable
		Archive torage engine no longer creates `.ARM` metadata file for each table.
5.1.16	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-16.html	NDB API: AbortOption now a member of dbOperation class with different values & behaviour, see The NdbOperation::AbortOption Type
		Create \| Alter Event now use session time zone
5.1.17	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-17.html	Merge tables now reject Insert Delayed
5.1.18	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-18.html	Cluster: changed storage specs for column specification
		Event tables changed to facilitate replication. Run mysql_upgrade before working with events.
		Cluster: Changed definition of mysql.ndb_apply_status table
		Changes in system variables related to plugins
		Dump events created pre-5.1.18 and restore only after upgrading to 5.1.18 or later. Problem fixed in 5.1.20.
5.1.19	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-19.html	Insert Delayed is changed to normal Insert if Insert uses functions that access tables or triggers, or is called from a function or trigger.
5.1.20	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-20.html	Log tables can no longer be partitioned
		mysqld_safe now supports error logging to syslog on systems that support logger command
		Error code values adjusted to match 5.0
5.1.21	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-21.html	Default log destination changed from Table to File.
		System variable `innodb_log_arch_dir` removed
		Rebuild indexes for columns that use eucjpms, euc_kr, gb2312, latin7, macce or ujis charsets
		mysqkd-nt.exe removed from Windows releases. Use mysqld.
		New columns in mysql.proc, mysql.events and information_schema.events to manage charsets & collations in stored programs
5.1.24	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-24.html	Reverted a 5.1.23 constant name change in NET structure in mysql_com.h
		Reverted a change in handling of Nulls in Updates See also http://dev.mysql.com/doc/refman/5.1/en/news-5-1-32.html
		Change in plugin location
		Rebuild indexes using utf_general_ci or ucs2_general_ci charsets
5.1.25	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-25.html	Detect metadata changes to tables or views referred to by prepared statements and automatically reprepare
5.1.27	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-27.html	Rename or drop partitioned tables using mixed case names before upgrading to 5.1.27 on Mac OS X
5.1.29	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-29.html	Changed default binary log mode from Mixed to Statement
		Check Table ... For Upgrade now checks for incorrect collation changes made in 5.1.21
5.1.36	http://dev.mysql.com/doc/refman/5.1/en/news-5-1-36.html	Changes in handling of plugins
5.5	http://dev.mysql.com/doc/refman/5.5/en/reserved-words.html	New reserved words in MySQL 5.5
5.5.0	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-0.html	New plugin interface
		Changes in error message language and charset
		Changes in access privileges for several statements
5.5.1	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-1.html	Changes in naming of semisynchronous plugins
5.5.2	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-2.html	Changes in plugin.h
5.5.3	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-3.html	log_bin_trust_routine_creators => log_bin_trust_function_creators and several other variable name changes Create Table(...)Type=... => Create Table(...) Engine=... Show Table Types => Show Engines TimeStamp(N) => TimeStamp() TimeStampAdd(...frac_second...) => TimeStampAdd(...microsecond...) Show InnoDB Status, Show Mutex Status => Show Engine InnoDB Status, Show Engine InnoDB Mutex Select wildcard aliases disallowed String conversions respect collation settings New columns in information_schema.routines Reset master \| Slave reset Last_IO_Error, Last_IO_Errno, Last_SQL_Error, Last_SQL_Errno in Show Slave Status
5.5.6	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-6.html	Sha2() & other encryption return values now respect connection character set & collation settings
5.5.7	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-7.html http://dev.mysql.com/doc/refman/5.6/en/news-5-6-1.html	Flush Logs no longer renames old logfile InnoDB now truncates using Create & Drop Table In statement-based replication, Insert Delayed now logged as Insert handler...Read disallows calls to stored functions
5.5.8	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-8.html	performance_schema table names now lower case, some columns renamed Flush Table With Read Lock redesigned
5.5.9	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-9.html http://dev.mysql.com/doc/refman/5.6/en/news-5-6-2.html	auto_increment values can no longer reach maximum BigInt Unsigned value
5.5.10	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-10.html	New C API library version
5.5.14	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-14.html http://dev.mysql.com/doc/refman/5.6/en/news-5-6-3.html	Class member change in audit plugin
5.5.18	http://dev.mysql.com/doc/refman/5.5/en/news-5-5-18.html	Several statements newly marked unsafe for statement-based replication
5.6	http://dev.mysql.com/doc/refman/5.6/en/reserved-words.html	New reserved words in MySQL 5.6 (warning: there are very many!)
5.6.1	http://dev.mysql.com/doc/refman/5.6/en/news-5-6-1.html	Several server variables removed Replication: database-level statements take precedence over table wildcards Lock Tables blocks Create Table
5.6.2	http://dev.mysql.com/doc/refman/5.6/en/news-5-6-2.html	Flush Master \| Slave removed
5.6.3	http://dev.mysql.com/doc/refman/5.6/en/news-5-6-3.html	Changes in timeout handling
5.6.4	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-4.html	Timestamp(n) no longer sets display width, now specifies 0<=n<=6 microsecond digits. InnoDB now supports FullText.
5.6.5	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-5.html	Any number of Timestamp columns may default to Now() on insert and/or on update.
5.6.6	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-6.html	innodb_file_per_table enabled (previously disabled), innodb_checksum_algorithm now CRC32 (previously InnoDB) binlog_checksum now CRC32 (previously NONE)
5.6.7	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-7.html	Alter Table commands that would lose data by changing a Foreign Key are now blocked. Replication: Within a transaction, Change Master To, Start Slave, Stop Slave and Reset Slave induce a Commit.
5.6.9	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-9.html	Several GTID-related variable name changes. Last_Insert_Id() now returns a Bigint Unsigned value, not a Bigint (signed) value.
5.6.11	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-11.html	backward-incompatible changes in partiton Key syntax and handling
5.6.12	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-12.html	Because IDENTIFIED WITH is intended for Grant statements that create a new user are now prohibited if the named account already exists.
5.6.13	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-13.html	Backward-incompativle performance schema change.
5.6.14	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-14.html	In 5.6.13 the statement/com/ abstract statement instrument in the Performance Schema setup_instruments table was renamed to statement/com/new_packet. That is reverted in 5.6.14.
5.6.15	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-15.html http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-3.html	Several more performance_schema renamings.
5.6.17	http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-17.html	`AES_DECRYPT()` and `AES_ENCRYPT()` take a vector argument to control block encryption mode.
5.6.32	https://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-32.html	`Load Data...` now rejects previously accepted invalid character data.
5.6.34	https://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-34.html	The variable `secure_file_priv` can be set to `NULL` to disable all import and export operations.
5.6.39	https://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-39.html	The sha256_password authentication plugin now accepts passwords only up to length 256, likewise the `PASSWORD() function when old_passwords=2.`
5.7.1	http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-1.html	Key partitioning hashing function changes in 5.5 make tables using key partitioning created on a 5.5 or later server incompatible with a 5.1 server.
5.7.2	http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-2.html	mysql.user.plugin now defined as Not Null, run mysql_upgrade. log_error_verbosity is preferred to log_warnings.
5.7.4	http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-4.html	mysql.user table has new columns password_last_changed and password_lifetime, run mysql_upgrade.
5.7.4	http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-4.html	Default `sync_binlog` setting changed from 0 to 1, improving data protection against disk crashes, but it can seriously worsen write performance.
5.7.5	http://dev.mysql.com/doc/refman/5.7/en/mysql-install-db.html	mysql_install_db isnow an executable written in C++ rather than a Perl script.
5.7.5	http://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#option_mysqld_innodb	InnoDB engine can no longer be disabled.
5.7.5	http://dev.mysql.com/doc/refman/5.7/en/account-upgrades.html	Support for pre-4.1 passwords removed.
5.7.5	http://dev.mysql.com/doc/refman/5.7/en/sql-mode.html#sql-mode-full	Many sql_mode changes.
5.7.5	http://dev.mysql.com/doc/refman/5.7/en/year.html	Year(2) removed, use Year(4).
5.7.6	http://dev.mysql.com/doc/refman/5.7/en/create-user.html http://dev.mysql.com/doc/refman/5.7/en/alter-user.html	Create User and Alter User commands massively reworked. Grant is also affected, as is mysql.user structureand use, and a semantic incompatibility in Set Password is created.
	http://dev.mysql.com/doc/refman/5.7/en/mysql-real-escape-string-quote.html	mysql_real_escape_string_quote() replaces mysql_real_escape_string() in C API.
	http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-6.html	InnoDB Tablespace files created before 5.1 can fail. Look for " tablespace data files" in the linked page.
5.7.8	http://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-8.html	Previously created Virtual generated columns must be recreated.
5.7.9	http://dev.mysql.com/doc/refman/5.7/en/mysql-options.html	New options in C API function mysql_options(). Usernames increase in length from 16 to 32 chars. Run the mysql_upgrade program.
	http://dev.mysql.com/doc/refman/5.7/en/upgrading-from-previous-series.html	Inner InnoDB file changes require clean InnoDB shutodwn in upgrade.
5.7.10	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-10.html	InnoDB 2-phase XA transactions are now always supported. The `innodb_support_xa` variable is deprecated.
5.7.12	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-12.html	Use the `--early-plugin-load` option to load a keyring plugin.
5.7.13	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-13.html	The `definer` and `grantor` columns in the `mysql` database increase to 32 chars to match the 5.7.9 change in `mysql.user` length. Run the mysql_upgrade program.
5.7.16	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-16.html	The `ignore_db_dirs` variable is deprecated, and removed in 8.0.
5.7.18	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-18.html#mysqld-5-7-18-compiling	`PROCEDURE ANALYSE()`, the `--temp-pool` server option, and support for DTrace are deprecated and removed in 8.0.
5.7.19	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-19.html#mysqld-5-7-19-account-managements	The `innodb_undo_logs` option is deprecated, will be removed; use `innodb_rollback_segments`. The libmysqld embedded server library is deprecated, will be removed in 8.0.
5.7.20	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-20.html#mysqld-5-7-20-deprecation-removal	`transaction_isolation` and `transaction_read_only` have been aliases for `tx_isolation` and `tx_read_only`; they're now deprecated, will be removed in 8.0. Use `transaction_isolation` and `transaction_read_only` instead. Also deprecated: references to table and column names using leading periods. The query cache, `FLUSH QUERY CACHE` and `RESET QUERY CACHE` statements; `SQL_CACHE` and `SQL_NO_CACHE SELECT` modifiers; `have_query_cache, ndb_cache_check_time, query_cache_limit, query_cache_min_res_unit, query_cache_size, query_cache_type, query_cache_wlock_invalidate` system variables; `Qcache_free_blocks, Qcache_free_memory, Qcache_hits, Qcache_inserts, Qcache_lowmem_prunes, Qcache_not_cached, Qcache_queries_in_cache, Qcache_total_blocks` status variables. Comment stripping by the mysql client program, and its `--comments, --skip-comments` options
5.7.21	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-21.html	The `innodb_undo_tablespaces` option is deprecated
5.7.22	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-22.html#mysqld-5-7-22-deprecation-removal	`DB2, MAXDB, MSSQL, MYSQL323, MYSQL40, ORACLE, POSTGRESQL, NO_FIELD_OPTIONS, NO_KEY_OPTIONS, NO_TABLE_OPTIONS` sql modes are deprecated, will be removed in 8.0. They will not replicate to 8.0.
5.7.23	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-23.html	Long partition table names required that `mysql.innodb_index_stats, mysql.innodb_table` columns be lengthened. Run mysql_upgrade.
5.7.24	https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-24.html#mysqld-5-7-24-deprecation-removal	Deprecated: placing table partitions in shared tablespaces, `CREATE TEMPORARY ABKE ... TABLESPACE=innodb_file_per_table \|\| TABLESPACE=innodb_temporary`. All will be removed.
8.0	https://dev.mysql.com/doc/refman/8.0/en/keywords.html	Reserved words, keywords in 8.0.
8.0.0	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-0.html#mysqld-8-0-0-account-management	Grant tables (`mysql.user, db, tables_priv, columns_priv, procs_priv, proxies_priv`) no longer use the MyISAM storage engine; they now use the InnoDB storage engine. Run mysql_upgrade. All commands that change these tables are transactional; partial completion will not replicate to 8.0. `Create\|Drop Function...` now causes an implicit commit The `utf8mb4` Unicode character set has a new general collation, utf8mb4_0900_ai_ci. The new data dictionary and the tables in the `mysql` database now all use InnoDB, so the system variable `innodb_read_only` now blocks all database writes. The deprecated mysql_install_db was removed. Foreign key names now have a maximum length of 64 chars. `ignore_db_dir` was removed. `routines, events, parameters` tables are no longer in the `mysql` db; they are in the sysem data dictionary `information_schemma`. See here for how to upgrade from 5.7 to 8.0. `performance_schema` now instruments server errors and warnings. The variable `validate_password_check_user_name` is now enabled by default, so when the plugin is enabled, it by default rejects a password matching the current session username. Spatial function names `Contains(), Disjoint(), Equals(), Intersects(), Overlaps(), Within()` have been replaced by their `MBR_` versions. These spatial function names are replaced by their `ST_` versions: Area(), AsBinary(), AsText(), AsWKB(), AsWKT(), Buffer(), Centroid(), ConvexHull(), Crosses(), Dimension(), Distance(), EndPoint(), Envelope(), ExteriorRing(), GeomCollFromText(), GeomCollFromWKB(), GeomFromText(), GeomFromWKB(), GeometryCollectionFromText(), GeometryCollectionFromWKB(), GeometryFromText(), GeometryFromWKB(), GeometryN(), GeometryType(), InteriorRingN(), IsClosed(), IsEmpty(), IsSimple(), LineFromText(), LineFromWKB(), LineStringFromText(), LineStringFromWKB(), MLineFromText(), MLineFromWKB(), MPointFromText(), MPointFromWKB(), MPolyFromText(), MPolyFromWKB(), MultiLineStringFromText(), MultiLineStringFromWKB(), MultiPointFromText(), MultiPointFromWKB(), MultiPolygonFromText(), MultiPolygonFromWKB(), NumGeometries(), NumInteriorRings(), NumPoints(), PointFromText(), PointFromWKB(), PointN(), PolyFromText(), PolyFromWKB(), PolygonFromText(), PolygonFromWKB(), SRID(), StartPoint(), Touches(), X(), Y(). Partitioning is now only don by storage engines, and only InnoDB does it, so the options `--partition, --skip-partition` are removed. Previously deprecated InnoDB file format variables `innodb_file_format, innodb_file_format_check, innodb_file_format_max, innodb_large_prefix` were removed. The mysqlcheck options `--fix-db-names, --fix-table-names` were removed.. Spatial arguments now elicit errors from `CONCAT(), CONCAT_WS()`. JSON functions such as `JSON_EXTRACT()` now acceot a quoted empty string as a key.
8.0.1	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-1.html	The default character set has been changed from `latin1` to `utf8mb4`. The default collation for `utf8mb4` was `utf8mb4_general_ci`, is now `utf8mb4_0900_ai_ci`. For the many consequent changes, see the link. The c/c++ source no longer has the `my_bool` type. Use `bool`; deprecated syntax has been removed. The deprecated `libmysqld` embedded server and `PROCEDURE ANALYSE()` have been removed. MySQL 8.0 requires the Microsoft Visual C++ 2015 Redistributable Package. Many `performance_schema` changes, run mysql_upgrade. `global_variables, session_variables, global_status, session_status` tables have moved from `information_schema` to `performance_schema`. Instead of the previously deprecated and now removed `information_schema` tables `innodb_locks, innodb_lock_waits tables`, use `performance_schema.data_locks, data_lock_waits`, or `sys.innodb_lock_waits, x$innodb_lock_waits` Views. For security reasons, in standalone and win builds the default `secure_file_priv` setting is now `NULL` rather than ''. /bin/bash is required to run mysqld_safe on Solaris. Server components and plugins can now define privileges dynamically at runtime. The spatial function `ST_Distance()` now detects `geometry` arguments. These spatial functions now accept just WKB arguments, no longer accept geometry arguments:`ST_GeomCollFromWKB(), ST_GeometryCollectionFromWKB(), ST_GeomFromWKB(), ST_GeometryFromWKB(), ST_LineFromWKB(), ST_LinestringFromWKB(), ST_MLineFromWKB(), ST_MultiLinestringFromWKB(), ST_MPointFromWKB(), ST_MultiPointFromWKB(), ST_MPolyFromWKB(), ST_MultiPolygonFromWKB(), ST_PointFromWKB()`. These spatial functions now interpret latitude and longitude in the order specified by the SRS, and accept an optional argument to override the default axis order: ST_GeomCollFromText(), ST_GeometryCollectionFromText(), ST_GeomCollFromTxt(), ST_GeomFromText(), ST_GeometryFromText(), ST_LineFromText(), ST_LinestringFromText(), ST_MLineFromText(), ST_MultiLinestringFromText(), ST_MPointFromText(), ST_MultiPointFromText(), ST_MPolyFromText(), ST_MultiPolygonFromText(), ST_PointFromText(), ST_PolyFromText(), ST_PolygonFromText(), ST_GeomCollFromWKB(), ST_GeometryCollectionFromWKB(), ST_GeomFromWKB(), ST_GeometryFromWKB(), ST_LineFromWKB(), ST_LinestringFromWKB(), ST_MLineFromWKB(), ST_MultiLinestringFromWKB(), ST_MPointFromWKB(), ST_MultiPointFromWKB(), ST_MPolyFromWKB(), ST_MultiPolygonFromWKB(), ST_PointFromWKB(), ST_PolyFromWKB(), ST_PolygonFromWKB(), ST_AsBinary(), ST_AsWKB(), ST_AsText(), ST_AsWKT().. `INSERT ... SELECT ... ON DUPLICATE KEY UPDATE` where `UPDATE` refers to `SELECT` columns could produce incorrect results if the `SELECT` was a `UNION`, so now they elicit an error. Write the `UNION` as a derived single table. Because of a bug fix, a View can no longer be replaced just by reference to `information_schema.Views`. Use `Show Create View`.
8.0.2	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-3.html	To log to the system log, you now need to load the `log_sink_syseventlog` log component and list it in `log_error_services`. partition management is much changed, see the link. Some plugins ,eg Group Replication, X Plugin, now use the `mysql.session` add d in 8.0, so if the version being upgraded from did not include `mysql.session` account, you will need to run mysql_upgrade. The spatial functions `ST_Contains(), ST_Crosses(), ST_Disjoint(), ST_Equals(), ST_Intersects(), ST_Overlaps(), ST_Touches(), ST_Within(), MBRContains(), MBRCoveredBy(), MBRCovers(), MBRDisjoint(), MBREquals(), MBRIntersects(), MBROverlaps(), MBRTouches(), MBRWithin()` now detect and handle `geometry` arguments. MySQL formerly took the first, now takes the last members with the same key name.
8.0.4	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-4.html	Regex now uses International Components for Unicode, multibyte safe with new functions. The default authentication plugin is now `caching_sha2_password`. Some `ST_*` functions now return errors for out-of-range params. MySWL now uses `binlog` as a base name for the binary log.
8.0.11	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-11.html	`DB2, MAXDB, MSSQL, MYSQL323, MYSQL40, ORACLE, POSTGRESQL, NO_FIELD_OPTIONS, NO_KEY_OPTIONS, NO_TABLE_OPTIONS` sql modes are removed. `GeomCollection[()]` is a synonym for `GeometryCollection[()]`, and preferred.
8.0.12	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-12.html	Some changes to `ST_*` functions, see link.
8.0.13	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-13.html	Changes to `log_syslog*` variable names. `GROUP BY` no longer supports `ASC \| DESC`.
8.0.14	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-14.html#mysqld-8-0-14-account-management	Support for secondary passwords, upgrading from 8.0.13 requires running mysql_upgrade.
8.0.16	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-16.html	InnoDB restores automatic generation of foreign key contraint names discontinued in 8.0.
8.0.20	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-20.html	Fixed ST_Contains(), which had returned nothing without > 0. Recreate spatial indexes.
8.0.21	https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-21.html	Access to `INFORMATION_SCHEMA.FILES` requires `PROCESS` privilege.