Security enhancement: Added the global max_prepared_stmt_count system variable to limit the total number of prepared statements in the server. This limits the potential for denial-of-service attacks based on running the server out of memory by preparing huge numbers of statements. The current number of prepared statements is available through the prepared_stmt_count system variable. (Bug#16365)

The mysql_upgrade command has been converted from a shell script to a C program, so it is available on non-Unix systems such as Windows. This program should be run for each MySQL upgrade. See 項4.5.4. 「mysql_upgrade — MySQL アップグレードのテーブル チェック」.

Binary distributions that include SSL support now are built using yaSSL when possible.

The MySQL-shared-compat-5.1.X-.i386.rpm shared compatibility RPMs no longer contain libraries for MySQL 5.0. This avoids a conflict because the 5.0 and 5.1 libraries share the same soname number. It contains libraries for 3.23, 4.0, 4.1, and 5.1. (Bug#19288)

The ONLY_FULL_GROUP_BY SQL mode now also applies to the HAVING clause. That is, columns not named in the GROUP BY clause cannot be used in the HAVING clause if not used in an aggregate function. (Bug#18739)

SQL syntax for prepared statements now supports ANALYZE TABLE, OPTIMIZE TABLE, and REPAIR TABLE. (Bug#19308)

XPath expressions passed to the ExtractValue() and UpdateXML() functions can now include the colon character (「 : 」). This enables use of these functions with XML which employs namespaces. (Bug#18170)

The bundled yaSSL library was upgraded to version 1.3.5. This improves handling of certain problems with SSL-related command options. (Bug#17737)

For the mysql client, typing Control-C causes mysql to attempt to kill the current statement. If this cannot be done, or Control-C is typed again before the statement is killed, mysql exits. Previously, Control-C caused mysql to exit in all cases. (Bug#1989)

Creating a table in an InnoDB database with a column name that matched the name of an internal InnoDB column (including DB_ROW_ID, DB_TRX_ID, DB_ROLL_PTR and DB_MIX_ID) would cause a crash. MySQL now returns error 1005 (cannot create table) with errno set to -1. (Bug#18934)

On Windows, some names such as nul, prn, and aux could not be used as filenames because they are reserved as device names. These are now allowable names in MySQL. They are encoded by appending @@@ to the name when the server creates the corresponding file or directory. This occurs on all platforms for portability of the corresponding database object between platforms. (Bug#17870)

Added the REFERENTIAL_CONSTRAINTS table to INFORMATION_SCHEMA. It provides information about foreign keys.

Added --debug option to Instance Manager.

Added the have_dynamic_loading system variable that indicates whether the server supports dynamic loading of plugins.

Added the sql_big_selects system variable to the output of SHOW VARIABLES.

You must now have the DROP privilege to drop table partitions. (Bug#17139)

NDB Cluster: It is now possible to perform a partial start of a cluster. That is, it is now possible to bring up the cluster without running ndbd --initial on all configured data nodes first. (Bug#18606)

NDB Cluster: It is now possible to restore a Cluster backup between big-endian and little-endian machines. (Bug#19255)

NDB Cluster: It is now possible to install MySQL with Cluster support to a non-default location and change the search path for font description files using either the --basedir or --character-sets-dir options. (Previously in MySQL 5.1, ndbd searched only the default path for character sets.)

In result set metadata, the MYSQL_FIELD.length value for BIT columns now is reported in number of bits. For example, the value for a BIT(9) column is 9. (Formerly, the value was related to number of bytes.) (Bug#13601)

Added the KEY_BLOCK_SIZE table option and index option. This can be used in CREATE TABLE, ALTER TABLE, and CREATE INDEX statements to provide a hint to the storage engine about the size to use for index key blocks. The engine is allowed to change the value if necessary.

Security fix: A malicious client, using specially crafted invalid login or COM_TABLE_DUMP packets was able to read uninitialized memory, which potentially, though unlikely in MySQL, could have led to an information disclosure. (CVE-2006-1516, CVE-2006-1517) Thanks to Stefano Di Paola <stefano.dipaola@wisec.it> for finding and reporting this bug.

Security fix: A malicious client, using specially crafted invalid COM_TABLE_DUMP packets was able to trigger an exploitable buffer overflow on the server. (CVE-2006-1518) Thanks to Stefano Di Paola <stefano.dipaola@wisec.it> for finding and reporting this bug.

NDB Cluster (Replication): Using the --binlog-do-db option caused problems with CREATE TABLE on the cluster acting as the replication master. (Bug#19492)

NDB Cluster: Some queries having a WHERE clause of the form c1=val1 OR c2 LIKE 'val2' were not evaluated correctly. (Bug # 17421)

NDB Cluster: Repeated use of the SHOW and ALL STATUS commands in the ndb_mgm client could cause the mgmd process to crash. (Bug#18591)

NDB Cluster: An issue with ndb_mgmd prevented more than 27 mysqld processes from connecting to a single cluster at one time. (Bug#17150)

Running myisampack followed by myisamchk with the --unpack option would corrupt the auto_increment key. (Bug#12633)

A view definition that referred to an alias in the HAVING clause could be saved in the .frm file with the alias replaced by the expression that it referred to, causing failure of subsequent SELECT * FROM view_name statements. (Bug#19573)

A compatibility issue with NPTL (Native POSIX Thread Library) on Linux could result in a deadlock with FLUSH TABLES WITH READ LOCK under some conditions. (Bug#20048)

MyISAM table deadlock was possible if one thread issued a LOCK TABLES request for write locks and then an administrative statement such as OPTIMIZE TABLE, if between the two statements another client meanwhile issued a multiple-table SELECT for some of the locked tables. (Bug#16986)

The patch for Bug#17164 introduced the problem that some outer joins were incorrectly converted to inner joins. (Bug#19816)

A NUL byte within a comment in a statement string caused the rest of the string not to be written to the query log, allowing logging to be bypassed. (CVE-2006-0903) (Bug#17667)

NDB Cluster: mysqld could crash when attempting an update if the cluster had failed previously. (Bug#18798)

mysql-test-run.pl started NDB even for test cases that didn't need it. (Bug#19083)

Selecting from a view that used GROUP BY on a non-constant temporal interval (such as DATE(col) + INTERVAL TIME_TO_SEC(col) SECOND could cause a server crash. (Bug#19490)

An outer join of two views that was written using { OJ ... } syntax could cause a server crash. (Bug#19396)

mysql displayed NULL for strings that are empty or contain only spaces. (Bug#19564)

A range access optimizer heuristic was invalid, causing some queries to be much slower in MySQL 5.0 than in 4.0. (Bug#17379, Bug#18940)

SELECT DISTINCT queries sometimes returned only the last row. (Bug#18068)

Eliminated some memory corruption problems that resultsd in double free or corruption errors and a server crash. (Bug#19154)

Use of CONVERT_TZ() in a stored function or trigger (or in a stored procedure called from a stored function or trigger) caused an error. (Bug#11081)

Some queries were slower in 5.0 than in 4.1 because some 4.1 cost-evaluation code had not been merged into 5.0. (Bug#14292)

MySQL-shared-compat-5.1.9-0.i386.rpm incorrectly depended on glibc 2.3 and could not be installed on a glibc 2.2 system. (Bug#16539)

Updates to a MEMORY table caused the size of BTREE indexes for the table to increase. (Bug#18160)

REPAIR TABLE did not restore the length for packed keys in tables created under MySQL 4.x. (Bug#17810)

The parser leaked memory when its stack needed to be extended. (Bug#18930)

When myisamchk needed to rebuild a table, AUTO_INCREMENT information was lost. (Bug#10405)

Use of --default-storage-engine=innodb resulted in an error with the server reporting that InnoDB was an unknown table type. (Bug#16691)

Executing a CREATE EVENT statement could cause 100% CPU usage. (Bug#19170)

After calling FLUSH STATUS, the max_used_connections variable did not increment for existing connections and connections which use the thread cache. (Bug#15933)

MySQL would not compile on Linux distributions that use the tinfo library. (Bug#18912)

An issue with file handling in the partitioning code could cause mysqld to crash when started and then stopped within a very short period of time. (Bug#19313)

NDB Cluster (Replication): When taking part in Cluster replication of tables containing BLOB columns, mysqld falsely reported a large memory leak in the replication buffers when there was none. (Bug#19247)

NDB Cluster: Stopping multiple nodes could cause node failure handling not to be completed. (Bug#19039)

NDB Cluster: A simultaneous DROP TABLE and table update operation utilising a table scan could trigger a node failure. (Bug#18597)

NDB Cluster: ndbd could sometimes fail to start with the error Node failure handling not completed following a graceful restart. (Bug#18550)

NDB Cluster: Backups could fail for large clusters with many tables, where the number of tables approached MaxNoOfTables. (Bug#17607)

NDB Cluster: A 5.1.6 or newer server did not read local checkpoints recorded by any other 5.1 version, thus preventing a system restart following an upgrade. (Bug#19333)

NDB Cluster: Trying to restore the apply_status table from a 5.0 cluster backup failed on a 5.1 server. (Bug#18935)

NDB Cluster (Disk Data): CREATE LOGFILE GROUP accepted values other than NDB or NDBCLUSTER in the ENGINE clause. (Bug#18604)

NDB Cluster (Disk Data): Omitting the required ENGINE clause from a CREATE LOGFILE GROUP or CREATE TABLESPACE statement caused the server to crash. An appropriate error message is now returned instead. (Bug#18603)

NDB Cluster: mysqldump included in its output data from the internal cluster database. (Bug#17840)

Event-creation statements enclosed in multi-line comments using /*!version_number ... */ syntax were not parsed correctly. (Bug#18078)

Within a trigger, CONNECTION_ID() did not return the connection ID of the thread that caused the trigger to be activated. (Bug#16461)

mysqltest incorrectly interpreted some ER_xxx error names given in the error command. (Bug#18495)

For single-SELECT union constructs of the form (SELECT ... ORDER BY order_list1 [LIMIT n]) ORDER BY order_list2, the ORDER BY lists were concatenated and the LIMIT clause was ignored. (Bug#18767)

Logging to the mysql.general_log and mysql.slow_log tables did not work for Windows builds because the CSV storage engine was unavailable. The CSV engine now is enabled in Windows builds. (Bug#17368)

LOAD DATA FROM MASTER would fail when trying to load the INFORMATION_SCHEMA database from the master, because the INFORMATION_SCHEMA system database would already exist on the slave. (Bug#18607)

The binary log would create an incorrect DROP query when creating temporary tables during replication. (Bug#17263)

CREATE VIEW statements would not be replicated to the slave if the --replicate-wild-ignore-table rule was enabled. (Bug#18715)

In mysqltest, --sleep=0 had no effect. Now it correctly causes sleep commands in test case files to sleep for 0 seconds. (Bug#18312)

Attempting to set the default value of an ENUM or SET column to NULL caused a server crash. (Bug#19145)

Index corruption could occur in cases when key_cache_block_size was not a multiple of myisam_block_size (for example, with key_cache_block_size=1536 and myisam_block_size=1024). (Bug#19079)

The sql_big_selects system variable was not displayed by SHOW VARIABLES. (Bug#17849)

The sql_notes and sql_warnings system variables were not always displayed correctly by SHOW VARIABLES (for example, they were displayed as ON after being set to OFF). (Bug#16195)

LAST_INSERT_ID() in a stored function or trigger returned zero. . (Bug#15728)

Use of CONVERT_TZ() in a view definition could result in spurious syntax or access errors. (Bug#15153)

The system_time_zone and version_* system variables could not be accessed via SELECT @@var_name syntax. (Bug#12792, Bug#15684)

Conversion of a number to a CHAR UNICODE string returned an invalid result. (Bug#18691)

Some fast ALTER TABLE operations (requiring no temporary table) did not work for all tables. (Bug#19011)

DELETE and UPDATE statements that used large NOT IN (value_list) clauses could use large amounts of memory. (Bug#15872)

Prevent recursive views caused by using RENAME TABLE on a view after creating it. (Bug#14308)

A LOCK TABLES statement that failed could cause MyISAM not to update table statistics properly, causing a subsequent CHECK TABLE to report table corruption. (Bug#18544)

A failed ALTER TABLE operation could fail to clean up a temporary .frm file. (Bug#18129)

For a reference to a non-existent stored function in a stored routine that had a CONTINUE handler, the server continued as though a useful result had been returned, possibly resulting in a server crash. (Bug#18787)

InnoDB did not use a consistent read for CREATE ... SELECT when innodb_locks_unsafe_for_binlog was set. (Bug#18350)

InnoDB could read a delete mark from its system tables incorrectly. (Bug#19217)

myisamchk and myisam_ftdump should allow either table names or .MYI filenames as arguments, but allowed only table names. (Bug#19220)

DROP DATABASE did not drop stored routines associated with the database if the database name was longer than 21 characters. (Bug#18344)

Avoid trying to include <asm/atomic.h> when it doesn't work in C++ code. (Bug#13621)

Executing SELECT on a large table that had been compressed within myisampack could cause a crash. (Bug#17917)

NDB Cluster (NDBAPI): Passing a nonexistent index name to NdbIndexScanOperation::setBound() caused a segmentation fault. (Bug#19088)

ALTER TABLE ... REBUILD PARTITION returned an inaccurate error message. (Bug#16819)

InnoDB: A DELETE followed by an INSERT and then by an UPDATE on a partitioned InnoDB table caused subsequent queries to return incorrect results. (Bug#17992)

NDB Cluster: A table insert or update of more than 128 bytes of data in a 4-replica Cluster could cause a node to crash. (Bug#18622)

NDB Cluster (Disk Data): Concurrent table schema operations and operations on log files groups, tablespaces, data files, or undofiles could lead to Cluster node failures. (Bug#18575)

NDB Cluster: An issue with replication caused a mysqld connected to a replicated cluster to crash when entering single user mode. (Bug#18535)

Successive ALTER TABLE ... DROP PARTITION statements on the same subpartitioned table could eventually cause the server to crash. (Bug#18962)

NDB Cluster: When attempting to create an index on a BIT or BLOB column, Error 743: Unsupported character set in table or index was returned instead of Error 906: Unsupported attribute type in index.

NDB Cluster: The Cluster binlog mysqld accepted updates even though the binary log was not set up, which could lead to updates missing from the binary log. (Bug#18932)

NDB Cluster: Concurrent INSERT and ROLLBACK statements from different connections could cause node failures. (Bug#19245)

NDB Cluster (Disk Data): Running an INSERT and a DELETE on a Disk Data table in the same transaction could cause a deadlock. (Bug#19244)

NDB Cluster (Disk Data): Issuing a CREATE LOGFILE GROUP statement during the drop of an NDB table would cause database corruption. (Bug#19141)

NDB Cluster: ndb_restore failed to restore a backup made from a 5.0 cluster to a 5.1 cluster. (Bug#18210)

NDB Cluster: Adding an index to an unsigned integer column did not work correctly. (Bug#18133)

NDB Cluster: A SELECT from an NDB table with ORDER BY indexed_column and a LIMIT clause would fail following ALTER TABLE. (Bug#18094)

NDB Cluster: Performing multiple ALTER TABLE operations on the same NDB table from different mysqld processes in the same cluster led to schema versioning errors when trying to access the table again following the restart of one of the mysqld processes. (Bug#16445)

NDB Cluster: Starting mysqld without --log-bin caused DDL statements on NDB tables to time out. (Bug#19214)

NDB Cluster: Fragment IDs were not being logged correctly, causing ndb_restore_log to fail. (Bug#18594)

Casting a string to DECIMAL worked, but casting a trimmed string (using LTRIM() or RTRIM()) resulted in loss of decimal digits. (Bug#17043)

NDB Cluster (Replication): Delete and update of rows in a table without a primary key failed on the slave. (Bug#17400)

NDB Cluster: On slow networks or CPUs, the management client SHOW command could sometimes erroneously show all data nodes as being master nodes belonging to nodegroup 0. (Bug#15530)

The XPath string-length() function was not implemented for use with ExtractValue(). (Bug#16319)

Fix the way that Instance Manager finds the version number of instances, so that it works properly when the executable name isn't the same as what the Instance Manager launched (such as when wrapping a libtool-wrapped executable from the source tree). (Bug#19059)

The server attempted to flush uninitialized log tables during SIGHUP processing, causing a crash. (Bug#18848)

If the second or third argument to BETWEEN was a constant expression such as '2005-09-01 - INTERVAL 6 MONTH and the other two arguments were columns, BETWEEN was evaluated incorrectly. (Bug#18618)

If the first argument to BETWEEN was a DATE or TIME column of a view and the other arguments were constants, BETWEEN did not perform conversion of the constants to the appropriate temporary type, resulting in incorrect evaluation. (Bug#16069)

ExtractValue function did not return character data within <![CDATA[]]> as expected. (Bug#18285)

Server and clients ignored the --sysconfdir option that was passed to configure. (Bug#15069)

It was possible to create a RANGE-partitioned table with a partition defined using the clause VALUES LESS THAN (NULL), even though such a partition could never contain any values whatsoever. (Bug#18752)

Running an ALTER TABLE on a partitioned table simultaneously experiencing a high number of concurrent DML statements could crash the server. (Bug#18572)

It was possible to use trailing spaces in the names of partitions and subpartitions. Attempting to do so now raises the error Incorrect partition name. (Bug#17973)

LIKE searches failed on a CHAR column used as the partitioning column of a table partitioned by KEY. (Bug#17946)

If the WHERE condition of a query contained an OR-ed FALSE term, the set of tables whose rows cannot serve for null-complements in outer joins was determined incorrectly. This resulted in blocking possible conversions of outer joins into joins by the optimizer for such queries. (Bug#17164)

The ExtractValue() function failed with a syntax error when the XPath expression used special characters such as Ñ (「N-tilde」). (Bug#16233)

Inserts failed with duplicate key errors on a table partitioned using an AUTO_INCREMENT column for the partitioning key. (Bug#18552, Bug#18753)

Delimited identifiers for partitions were not being treated the same as delimited identifiers for other database objects (such as tables and columns) with regard to allowed characters. (Bug#18750)

A query on a table partitioned or subpartitioned by HASH did not display all results when using a WHERE condition involving a column used in the hashing expression. (Bug#18423, Bug#18329)

If the server were built without partition support, it was possible to run partitioning-related statements with no errors or warnings, even though these statements would have no effect. Now such statements are disallowed unless the server has been compiled using the --with-partition option. (Bug#15561)

NDB Cluster: In a 2-node cluster with a node failure, restarting the node with a low value for StartPartialTimeout could cause the cluster to come up partitioned (「split-brain」 issue). (Bug#16447)

A similar issue could occur when the cluster was first started with a sufficiently low value for this parameter. (Bug#18612)

NDB Cluster: On systems with multiple network interfaces, data nodes would get 「stuck」 in startup phase 2 if the interface connecting them to the management server was working on node startup while the interface interconnecting the data nodes experienced a temporary outage. (Bug#15695)

NDB Cluster: Unused open handlers for tables in which the metadata had changed were not properly closed. This could result in stale results from Cluster tables following an ALTER TABLE. (Bug#13228)

NDB Cluster: Uninitialized internal variables could lead to unexpected results. (Bug#11033, Bug#11034)

The presence of multiple equalities in a condition after reading a constant table could cause the optimizer not to use an index. This resulted in certain queries being much slower than in MySQL 4.1. (Bug#16504)

A recent change caused the mysql client not to display NULL values correctly and to display numeric columns left-justified rather than right-justified. The problems have been corrected. (Bug#18265)

InnoDB failure to release an adaptive hash index latch could cause a server crash if the query cache was enabled. (Bug#15758)

InnoDB: ALTER TABLE to add or drop a foreign key for an InnoDB table had no effect. (Bug#18477)

NDB Cluster: Attempting to create an index using multiple columns on an explicitly partitioned table in a replicated Cluster database could cause the master mysqld process to crash. (Bug#18284)

NDB Cluster: Queries using ORDER BY pkN failed against a LIST-partitioned Cluster table having a multi-column primary key, where pkN represents one of the columns making up the primary key. (Bug#18598)

Updating a field value when also requesting a lock with GET_LOCK() would cause slave servers in a replication environment to terminate. (Bug#17284)