Performance of SELECT * retrievals from INFORMATION_SCHEMA.COLUMNS was improved slightly. (Bug#38918)

Previously, index hints did not work for FULLTEXT searches. Now they work as follows:

For natural language mode searches, index hints are silently ignored. For example, IGNORE INDEX(i) is ignored with no warning and the index is still used.

For boolean mode searches, index hints with FOR ORDER BY or FOR GROUP BY are silently ignored. Index hints with FOR JOIN or no FOR modifier are honored. In contrast to how hints apply for non-FULLTEXT searches, the hint is used for all phases of query execution (finding rows and retrieval, grouping, and ordering). This is true even if the hint is given for a non-FULLTEXT index. (Bug#38842)

Partitioning: Replication: Changing the transaction isolation level while replicating partitioned InnoDB tables could cause statement-based logging to fail. (Bug#39084)

Partitioning: This bug was introduced in MySQL 5.1.29. (Bug#40954)

This regression was introduced by Bug#30573, Bug#33257, Bug#33555.

Partitioning: With READ COMMITTED transaction isolation level, InnoDB uses a semi-consistent read that releases non-matching rows after MySQL has evaluated the WHERE clause. However, this was not happening if the table used partitions. (Bug#40595)

Partitioning: For a partitioned table having an AUTO_INCREMENT column: If the first statement following a start of the server or a FLUSH TABLES statement was an UPDATE statement, the AUTO_INCREMENT column was not incremented correctly. (Bug#40176)

Partitioning: The server attempted to execute the statements ALTER TABLE ... ANALYZE PARTITION, ALTER TABLE ... CHECK PARTITION, ALTER TABLE ... OPTIMIZE PARTITION, and ALTER TABLE ... REORGANIZE PARTITION on tables that were not partitioned. (Bug#39434)

See also Bug#20129.

Partitioning: The value of the CREATE_COLUMNS column in INFORMATION_SCHEMA.TABLES was not partitioned for partitioned tables. (Bug#38909)

Partitioning: When executing an ORDER BY query on a partitioned InnoDB table using an index that was not in the partition expression, the results were sorted on a per-partition basis rather than for the table as a whole. (Bug#37721)

Partitioning: Dropping or creating an index on a partitioned table managed by the InnoDB Plugin locked the table. (Bug#37453)

Partitioning: Partitioned table checking sometimes returned a warning with an error code of 0, making proper response to errors impossible. The fix also renders the error message subject to translation in non-English deployments. (Bug#36768)

Partitioning: When SHOW CREATE TABLE was used on a partitioned table, all of the table's PARTITION and SUBPARTITION clauses were output on a single line, making it difficult to read or parse. (Bug#14326)

Replication: With row-based replication, UPDATE and DELETE statements using LIMIT and a table's primary key could produce different results on the master and slave. (Bug#38230)

Accessing user variables within triggers could cause a server crash. (Bug#40770)

For single-table UPDATE statements, an assertion failure resulted from a runtime error in a stored function (such as a recursive function call or an attempt to update the same table as in the UPDATE statement). (Bug#40745)

Prepared statements allowed invalid dates to be inserted when the ALLOW_INVALID_DATES SQL mode was not enabled. (Bug#40365)

mc.exe is no longer needed to compile MySQL on Windows. This makes it possible to build MySQL from source using Visual Studio Express 2008. (Bug#40280)

Support for the revision field in .frm files has been removed. This addresses the downgrading problem introduced by the fix for Bug#17823. (Bug#40021)

Retrieval speed from the following INFORMATION_SCHEMA tables was improved by shortening the VARIABLE_VALUE column to 1024 characters: GLOBAL_VARIABLES, SESSION_VARIABLES, GLOBAL_STATUS, and SESSION_STATUS.

As a result of this change, any variable value longer than 1024 characters will be truncated with a warning. This affects only the init_connect system variable. (Bug#39955)

If the operating system is configured to return leap seconds from OS time calls or if the MySQL server uses a time zone definition that has leap seconds, functions such as NOW() could return a value having a time part that ends with :59:60 or :59:61. If such values are inserted into a table, they would be dumped as is by mysqldump but considered invalid when reloaded, leading to backup/restore problems.

Now leap second values are returned with a time part that ends with :59:59. This means that a function such as NOW() can return the same value for two or three consecutive seconds during the leap second. It remains true that literal temporal values having a time part that ends with :59:60 or :59:61 are considered invalid.

For additional details about leap-second handling, see Section 9.7.2, “Time Zone Leap Second Support”. (Bug#39920)

The server could crash during a sort-order optimization of a dependent subquery. (Bug#39844)

With the ONLY_FULL_GROUP_BY SQL mode enabled, the check for non-aggregated columns in queries with aggregate functions, but without a GROUP BY clause was treating all the parts of the query as if they were in the select list. This is fixed by ignoring the non-aggregated columns in the WHERE clause. (Bug#39656)

CHECK TABLE failed for MyISAM INFORMATION_SCHEMA tables. (Bug#39541)

On 64-bit Windows systems, the server accepted key_buffer_size values larger than 4GB, but allocated less. (For example, specifying a value of 5GB resulted in 1GB being allocated.) (Bug#39494)

Use of the PACK_KEYS or MAX_ROWS table option in ALTER TABLE should have triggered table reconstruction but did not. (Bug#39372)

The server returned a column type of VARBINARY rather than DATE as the result from the COALESCE(), IFNULL(), IF(), GREATEST(), or LEAST() functions or CASE expression if the result was obtained using filesort in an anonymous temporary table during the query execution. (Bug#39283)

A server built using yaSSL for SSL support would crash if configured to use an RSA key and a client sent a cipher list containing a non-RSA key as acceptable. (Bug#39178)

When built with Valgrind, the server failed to access tables created with the DATA DIRECTORY or INDEX DIRECTORY table option. (Bug#39102)

With binary logging enabled CREATE VIEW was subject to possible buffer overwrite and a server crash. (Bug#39040)

The fast mutex implementation was subject to excessive lock contention. (Bug#38941)

Use of InnoDB monitoring (SHOW ENGINE INNODB STATUS or one of the InnoDB Monitor tables) could cause a server crash due to invalid access to a shared variable in a concurrent environment. (Bug#38883)

If delayed insert failed to upgrade the lock, it did not free the temporary memory storage used to keep newly constructed BLOB values in memory, resulting in a memory leak. (Bug#38693)

On Windows, a five-second delay occurred at shutdown of applications that used the embedded server. (Bug#38522)

On Solaris, a scheduling policy applied to the main server process could be unintentionally overwritten in client-servicing threads. (Bug#38477)

On Windows, the embedded server would crash in mysql_library_init() if the language file was missing. (Bug#38293)

Queries with a HAVING clause could return a spurious row. (Bug#38072)

The Event Scheduler no longer logs “started in thread” or “executed” successfully messages to the error log. (Bug#38066)

A SELECT with a NULL NOT IN condition containing a complex subquery from the same table as in the outer select caused an assertion failure. (Bug#37894)

Use of an uninitialized constant in EXPLAIN evaluation caused an assertion failure. (Bug#37870)

Renaming an ARCHIVE table to the same name with different lettercase and then selecting from it could cause a server crash. (Bug#37719)

TIMEDIFF() was erroneously treated as always returning a positive result. Also, CAST() of TIME values to DECIMAL dropped the sign of negative values. (Bug#37553)

mysqlcheck used SHOW FULL TABLES to get the list of tables in a database. For some problems, such as an empty .frm file for a table, this would fail and mysqlcheck then would neglect to check other tables in the database. (Bug#37527)

Updating a view with a subquery in the CHECK option could cause an assertion failure. (Bug#37460)

Statements that displayed the value of system variables (for example, SHOW VARIABLES) expect variable values to be encoded in character_set_system. However, variables set from the command line such as basedir or datadir were encoded using character_set_filesystem and not converted correctly. (Bug#37339)

CREATE INDEX could crash with InnoDB plugin 1.0.1. (Bug#37284)

On a 32-bit server built without big tables support, the offset argument in a LIMIT clause might be truncated due to a 64-bit to 32-bit cast. (Bug#37075)

Use of CONVERT() with GROUP BY to convert numeric values to CHAR could return truncated results. (Bug#36772)

The mysql client, when built with Visual Studio 2005, did not display Japanese characters. (Bug#36279)

Setting the slave_compressed_protocol system variable to DEFAULT failed in the embedded server. (Bug#35999)

The columns that store character set and collation names in several INFORMATION_SCHEMA tables were lengthened because they were not long enough to store some possible values: SCHEMATA, TABLES, COLUMNS, CHARACTER_SETS, COLLATIONS, and COLLATION_CHARACTER_SET_APPLICABILITY. (Bug#35789)

Selecting from an INFORMATION_SCHEMA table into an incorrectly defined MERGE table caused an assertion failure. (Bug#35068)

perror on Windows did not know about Win32 system error codes. (Bug#34825)

EXPLAIN EXTENDED evaluation of aggregate functions that required a temporary table caused a server crash. (Bug#34773)

SHOW GLOBAL STATUS shows values that aggregate the session status values for all threads. This did not work correctly for the embedded server. (Bug#34517)

mysqldumpslow did not aggregate times. (Bug#34129)

mysql_config did not output -ldl (or equivalent) when needed for --libmysqld-libs, so its output could be insufficient to build applications that use the embedded server. (Bug#34025)

For a stored procedure containing a SELECT * ... RIGHT JOIN query, execution failed for the second call. (Bug#33811)

Previously, use of index hints with views (which do not have indexes) produced the error ERROR 1221 (HY000): Incorrect usage of USE/IGNORE INDEX and VIEW. Now this produces ERROR 1176 (HY000): Key '...' doesn't exist in table '...', the same error as for base tables without an appropriate index. (Bug#33461)

Execution of a prepared statement that referred to a system variable caused a server crash. (Bug#32124)

Some division operations produced a result with incorrect precision. (Bug#31616)

Some SHOW statements and retrievals from the INFORMATION_SCHEMA TRIGGERS and EVENTS tables used a temporary table and incremented the Created_tmp_disk_tables status variable, due to the way that TEXT columns are handled. The TRIGGERS.SQL_MODE, TRIGGERS.DEFINER, and EVENTS.SQL_MODE columns now are VARCHAR to avoid this problem. (Bug#29153)

For several read only system variables that were viewable with SHOW VARIABLES, attempting to view them with SELECT @@var_name or set their values with SET resulted in an unknown system variable error. Now they can be viewed with SELECT @@var_name and attempting to set their values results in a message indicating that they are read only. (Bug#28234)

SSL support was not included in some “generic” RPM packages. (Bug#26760)

The Questions status variable is intended as a count of statements sent by clients to the server, but was also counting statements executed within stored routines. (Bug#24289)

Setting the session value of the max_allowed_packet or net_buffer_length system variable was allowed but had no effect. The session value of these variables is now read only. (Bug#22891)

A race condition between the mysqld.exe server and the Windows service manager could lead to inability to stop the server from the service manager. (Bug#20430)