Incompatible Change: In MySQL 5.1.6, when log tables were implemented, the default log destination for the general query and slow query log was TABLE. This default has been changed to FILE, which is compatible with MySQL 5.0, but incompatible with earlier releases of MySQL 5.1 from 5.1.6 to 5.1.20. If you are upgrading from MySQL 5.0 to this release, no logging option changes should be necessary. However, if you are upgrading from 5.1.6 through 5.1.20 to this release and were using TABLE logging, use the --log-output=TABLE option explicitly to preserve your server's table-logging behavior.

In MySQL 5.1.x, this bug was addressed twice because it turned out that the default was set in two places, only one of which was fixed the first time. (Bug#29993)

Incompatible Change: The server now includes dtoa, a library for conversion between strings and numbers by David M. Gay. In MySQL, this library provides the basis for improved conversion between string or DECIMAL values and approximate-value (FLOAT/DOUBLE) numbers:

Because the conversions produced by this library differ in some cases from previous results, the potential exists for incompatibilities in applications that rely on previous results. For example, applications that depend on a specific exact result from previous conversions might need adjustment to accommodate additional precision.

For additional information about the properties of dtoa conversions, see Section 11.2.2, “Type Conversion in Expression Evaluation”.

See also Bug#12860, Bug#21497, Bug#26788, Bug#24541, Bug#34015

Important Change: MySQL Cluster: Packaging: Beginning with this release, standard MySQL 6.0 binaries are no longer built with support for the NDBCLUSTER storage engine, and the NDBCLUSTER code included in 6.0 mainline sources is no longer guaranteed to be maintained or supported. Those using MySQL Cluster in MySQL 6.0.4 and earlier MySQL 6.0 mainline releases should upgrade to MySQL Cluster NDB 6.2.15 or a later MySQL Cluster NDB 6.2 or 6.3 release. (Bug#36193)

Important Change: Added a ROUTINE_TYPE column to the INFORMATION_SCHEMA.PARAMETERS table, to make it possible to distinguish like-named parameters of stored routines and stored functions having the same names. See Section 26.26, “The INFORMATION_SCHEMA PARAMETERS Table”, for more information. (Bug#33106)

Replication: Introduced the slave_exec_mode system variable to control whether idempotent or strict mode is used for replication conflict resolution. Idempotent mode suppresses duplicate-key, no-key-found, and some other errors, and is needed for circular replication, multi-master replication, and some other complex replication setups when using MySQL Cluster. Strict mode is the default. (Bug#31609)

Replication: When running the server with --binlog-format=MIXED or --binlog-format=STATEMENT, a query that referred to a system variable used the slave's value when replayed on the slave. This meant that, if the value of a system variable was inserted into a table, the slave differed from the master. Now, statements that refer to a system variable are marked as “unsafe”, which means that:

(Bug#31168)

See also Bug#34732

In the INFORMATION_SCHEMA database, the FALCON_DATABASE_IO table was renamed to FALCON_TABLESPACE_IO. (Bug#35490)

For boolean options, the option-processing library now prints additional information in the --help message: If the option is enabled by default, the message says so and indicates that the --skip form of the option disables the option. This affects all compiled MySQL programs that use the library. (Bug#35224)

The PROCESS privilege now is required to start or stop the InnoDB monitor tables (see linkend="innodb-monitor"/>). Previously, no privilege was required. (Bug#34053)

For binary .tar.gz packages, mysqld and other binaries now are compiled with debugging symbols included to enable easier use with a debugger. If you do not need debugging symbols and are short on disk space, you can use strip to remove the symbols from the binaries. (Bug#33252)

Several undocumented C API functions were removed: mysql_manager_close(), mysql_manager_command(), mysql_manager_connect(), mysql_manager_fetch_line(), and mysql_manager_init(). (Bug#31954)

The C API contained several undocumented functions that have been removed: mysql_disable_reads_from_master(), mysql_disable_rpl_parse(), mysql_enable_reads_from_master(), mysql_enable_rpl_parse(), mysql_master_query(), mysql_master_send_query(), mysql_reads_from_master_enabled(), mysql_rpl_parse_enabled(), mysql_rpl_probe(), mysql_rpl_query_type(), mysql_set_master(), mysql_slave_query(), and mysql_slave_send_query(). (Bug#31952)

Formerly, when the MySQL server crashed, the generated stack dump was numeric and required external tools to properly resolve the names of functions. This is not very helpful to users having a limited knowledge of debugging techniques. In addition, the generated stack trace contained only the names of functions and was formatted differently for each platform due to different stack layouts.

Now it is possible to take advantage of newer versions of the GNU C Library provide a set of functions to obtain and manipulate stack traces from within the program. On systems that use the ELF binary format, the stack trace contains important information such as the shared object where the call was generated, an offset into the function, and the actual return address. Having the function name also makes possible the name demangling of C++ functions.

The library generates meaningful stack traces on the following platforms: i386, x86_64, PowerPC, IA64, Alpha, and S390. On other platforms, a numeric stack trace is still produced, and the use of the resolve_stack_dump utility is still required. (Bug#31891)

mysqltest now has mkdir and rmdir commands for creating and removing directories. (Bug#31004)

The LAST_EXECUTED column of the INFORMATION_SCHEMA.EVENTS table now indicates when the event started executing rather than when it finished executing. As a result, the ENDS column is never less than LAST_EXECUTED. (Bug#29830)

The mysql_odbc_escape_string() C API function has been removed. It has multi-byte character escaping issues, doesn't honor the NO_BACKSLASH_ESCAPES SQL mode and is not needed anymore by Connector/ODBC as of 3.51.17. (Bug#29592)

The server uses less memory when loading privileges containing table grants. (Patch provided by Google.) (Bug#25175)

Added the Uptime_since_flush_status status variable, which indicates the number of seconds since the most recent FLUSH STATUS statement. (From Jeremy Cole) (Bug#24822)

Added the SHOW PROFILES and SHOW PROFILE statements to display statement profile data, and the accompanying INFORMATION_SCHEMA.PROFILING table. Profiling is controlled via the profiling and profiling_history_size session variables. see Section 12.5.6.28, “SHOW PROFILES and SHOW PROFILE Syntax”, and Section 26.27, “The INFORMATION_SCHEMA PROFILING Table”. (From Jeremy Cole)

The profiling feature is enabled via a new --enable-profiling opion to configure. (Bug#24795)

The performance of internal functions that trim multiple spaces from strings when comparing them has been improved. (Bug#14637)

Added the SHA2() function, which calculates the SHA-2 family of hash functions (SHA-224, SHA-256, SHA-384, and SHA-512). (Contributed by Bill Karwin) (Bug#13174)

The new read-only global system variables report_host, report_password, report_port, and report_user system variables provide runtime access to the values of the corresponding --report-host, --report-password, --report-port, and --report-user options.

Formerly it was possible to specify an innodb_flush_method value of fdatasync to obtain the default flush behavior of using fdatasync() for flushing. This is no longer possible because it can be confusing that a value of fdatasync causes use of fsync() rather than fdatasync().

Two new statements, BACKUP DATABASE and RESTORE, have been added for backup and restore operations. See Section 6.3, “Using BACKUP DATABASE and RESTORE”.

The use of InnoDB hash indexes now can be controlled by setting the new innodb_adaptive_hash_index system variable at server startup. By default, this variable is enabled. See Section 13.6.13.3, “Adaptive Hash Indexes”.

The argument for the mysql-test-run.pl --do-test and --skip-test options is now interpreted as a Perl regular expression if there is a pattern metacharacter in the argument value. This allows more flexible specification of which tests to perform or skip.

The Instance Manager (mysqlmanager) has been discontinued and is no longer provided in MySQL releases.

Important Change: Security Fix: It was possible to circumvent privileges through the creation of MyISAM tables employing the DATA DIRECTORY and INDEX DIRECTORY options to overwrite existing table files in the MySQL data directory. Use of the MySQL data directory in DATA DIRECTORY and INDEX DIRECTORY is now disallowed. This is now also true of these options when used with partitioned tables and individual partitions of such tables. (Bug#32167, CVE-2008-2079)

Security Fix: A client that connects to a malicious server could be tricked by the server into sending files from the client host to the server. This occurs because the libmysqlclient client library would respond to a FETCH LOCAL FILE request from the server even if the request is sent for statements from the client other than LOAD DATA LOCAL INFILE. The client library has been modified to respond to a FETCH LOCAL FILE request from the server only if is is sent in response to a LOAD DATA LOCAL INFILE statement from the client.

The client library now also checks whether CLIENT_LOCAL_FILE is set and refuses to send a local file if not.

(Bug#29605)

Important Change: Security Enhancement: On Windows Vista and Windows Server 2008, a user without administrative privileges does not have write permissions to the Program Files directory where MySQL and the associated data files are normally installed. Using data files located in the standard Program Files installation directory could therefore cause MySQL to fail, or lead to potential security issues in an installed instance.

To address the problem, on Windows XP, Windows Vista and Windows Server 2008, the datafiles and data file configuration are now set to the Microsoft recommended AppData folder. The AppData folder is typically located within the user's home directory.

(Bug#34593)

Security Enhancement: It was possible to force an error message of excessive length which could lead to a buffer overflow. This has been made no longer possible as a security precaution. (Bug#32707)

Partitioning: Incompatible Change: The following statements did not function correctly with corrupted or crashed tables and have been removed:

ALTER TABLE ... REBUILD PARTITION is unaffected by this change and continues to be available. This statement and ALTER TABLE ... REORGANIZE PARTITION may be used to analyze and optimize partitioned tables, since these operations cause the partition files to be rebuilt. (Bug#20129)

Incompatible Change: In MySQL 5.1.23, the last_errno and last_error members of the NET structure in mysql_com.h were renamed to client_last_errno and client_last_error. This was found to cause problems for connectors that use the internal NET structure for error handling. The change has been reverted. (Bug#34655)

See also Bug#12713

Incompatible Change: The parser accepted illegal syntax in a FOREIGN KEY clause:

These illegal syntaxes are now properly rejected. Existing applications that used them will require adjustment. (Bug#34455)

Incompatible Change: It is no longer possible to create CSV tables with NULL columns. However, for backwards compatibility, you can continue to use such tables that were created in previous MySQL releases. (Bug#32050)

Incompatible Change: For packages that are built within their own prefix (for example, /usr/local/mysql) the plugin directory will be lib/plugin. For packages that are built to be installed into a system-wide prefix (such as RPM packages with a prefix of /usr), the plugin directory will be lib/mysql/plugin to ensure a clean /usr/lib hierarchy. In both cases, the $pkglibdir configuration setting is used at build time to set the plugin directory.

The current plugin directory location is available as the value of the plugin_dir system variable as before, but the mysql_config script now has a --plugindir option that can be used externally to the server by third-party plugin writers to obtain the default plugin directory pathname and configure their installation directory appropriately. (Bug#31736)

Incompatible Change: Inserting a row with a NULL value for a DATETIME column results in a CSV file that the storage engine cannot read.

All CSV tables now need to be defined with each column marked as NOT NULL. An error is raised if you try to create a CSV table with columns that are not defined with NOT NULL. (Bug#31473, Bug#32817)

Incompatible Change: The utf8_general_ci and ucs2_general_ci collations did not sort the letter "U+00DF SHARP S" equal to 's'.

As a result of this fix, any indexes on columns that use these collations (but only columns that use SHARP S) must be rebuilt when upgrading to 6.0.5 or higher. To do this, use ALTER TABLE to drop and re-add the indexes, or mysqldump to dump the affected tables and mysql to reload the dump file. (Bug#27877)

See also Bug#37046

Incompatible Change: Several changes were made to the processing of multiple-table DELETE statements:

Statements containing alias constructs that are no longer allowed must be rewritten. (Bug#27525)

See also Bug#30234

Important Change: Replication: When the master crashed during an update on a transactional table while in AUTOCOMMIT mode, the slave failed. This fix causes every transaction (including AUTOCOMMIT transactions) to be recorded in the binlog as starting with a BEGIN and ending with a COMMIT or ROLLBACK. (Bug#26395)

Important Change: It was possible to use FRAC_SECOND as a synonym for MICROSECOND with DATE_ADD(), DATE_SUB(), and INTERVAL; now, using FRAC_SECOND with anything other than TIMESTAMPADD() or TIMESTAMPDIFF() produces a syntax error.

It is now possible (and preferable) to use MICROSECOND with TIMESTAMPADD() and TIMESTAMPDIFF(), and FRAC_SECOND is now deprecated. (Bug#33834)

Important Change: InnoDB free space information is now shown in the Data_free column of SHOW TABLE STATUS and in the DATA_FREE column of the INFORMATION_SCHEMA.TABLES table. (Bug#32440)

This regression was introduced by Bug#11379

Important Change: The server handled truncation of values having excess trailing spaces into CHAR, VARCHAR, and TEXT columns in different ways. This behavior has now been made consistent for columns of all three of these types, and now follows the existing behavior of VARCHAR columns in this regard; that is, a Note is always issued whenever such truncation occurs.

This change does not affect columns of these three types when using a binary encoding; BLOB columns are also unaffected by the change, since they always use a binary encoding. (Bug#30059)

Important Change: An AFTER UPDATE trigger was not invoked when the UPDATE did not make any changes to the table for which the trigger was defined. Now AFTER UPDATE triggers behave the same in this regard as do BEFORE UPDATE triggers, which are invoked whether the UPDATE makes any changes in the table or not. (Bug#23771)

Replication: Important Note: Network timeouts between the master and the slave could result in corruption of the relay log. This fix rectifies a long-standing replication issue when using unreliable networks, including replication over wide area networks such as the Internet. If you experience reliability issues and see many You have an error in your SQL syntax errors on replication slaves, we strongly recommend that you upgrade to a MySQL version which includes this fix. (Bug#26489)

MySQL Cluster: When all data and SQL nodes in the cluster were shut down abnormally (that is, other than by using STOP in the cluster management client), ndb_mgm used excessive amounts of CPU. (Bug#33237)

MySQL Cluster: There was a short interval during the startup process prior to the beginning of heartbeat detection such that, were an API or management node to reboot or a network failure to occur, data nodes could not detect this, with the result that there could be a lingering connection. (Bug#28445)

Partitioning: In some cases, matching rows from a partitioned MyISAM using a BIT column as the primary key were not found by queries. (Bug#34358)

Partitioning: Enabling innodb_file_per_table produced problems with partitioning and tablespace operations on partitioned InnoDB tables, in some cases leading to corrupt partitions or causing the server to crash. (Bug#33429)

Partitioning: A table defined using PARTITION BY KEY and having a BIT column referenced in the partitioning key did not behave correctly; some rows could be inserted into the wrong partition, causing wrong results to be returned from queries. (Bug#33379)

Partitioning: It was possible to partition a table to which a foreign key referred. (Bug#32948)

Partitioning: When ALTER TABLE DROP PARTITION was executed on a table on which there was a trigger, the statement failed with an error. This occurred even if the trigger did not reference any tables. (Bug#32943)

Partitioning: A query of the form SELECT col1 FROM table GROUP BY (SELECT col2 FROM table LIMIT 1); against a partitioned table having a SET column crashed the server. (Bug#32772)

Partitioning: SHOW CREATE TABLE misreported the value of AUTO_INCREMENT for partitioned tables using either of the InnoDB or ARCHIVE storage engines. (Bug#32247)

Partitioning: Selecting from INFORMATION_SCHEMA.PARTITIONS while partition management statements (for example, ALTER TABLE ... ADD PARTITION) were executing caused the server to crash. (Bug#32178)

Partitioning: An error in the internal function mysql_unpack_partition() led to a fatal error in subsequent calls to open_table_from_share(). (Bug#32158)

Partitioning: Currently, all partitions of a partitioned table must use the same storage engine. One may optinally specify the storage engine on a per-partition basis; however, where this is the done, the storage engine must be the same as used by the table as a whole. ALTER TABLE did not enforce these rules correctly, the result being that incaccurate error messages were shown when trying to use the statement to change the storage engine used by an individual partition or partitions. (Bug#31931)

Partitioning: ORDER BY ... DESC did not always work correctly when selecting from partitioned tables. (Bug#31890)

See also Bug#31001

Partitioning: ALTER TABLE ... COALESCE PARTITION on a table partitioned by [LINEAR] HASH or [LINEAR] KEY caused the server to crash. (Bug#30822)

Partitioning: When the range access method was used on a partitioned Falcon table, the entire index was scanned. For partitioned tables using other storage engines, a related issue caused an ordered range scan to return some rows twice. (Bug#30573, Bug#33257)

Partitioning: LIKE queries on tables partitioned by KEY could return incomplete results. The problem was observed with the Falcon storage engine, but could affect third-party storage engines as well. (Bug#30480)

See also Bug#29320, Bug#29493, Bug#30563

Partitioning: Using the DATA DIRECTORY and INDEX DIRECTORY options for partitions with CREATE TABLE or ALTER TABLE statements appeared to work on Windows, although they are not supported by MySQL on Windows systems, and subsequent attempts to use the tables referenced caused errors. Now these options are disabled on Windows, and attempting to use them generates a warning. (Bug#30459)

Partitioning: It was not possible to insert the greatest possible value for a given data type into a partitioned table. For example, consider a table defined as shown here:

CREATE TABLE t (c BIGINT UNSIGNED)
    PARTITION BY RANGE(c) (
      PARTITION p0 VALUES LESS THAN MAXVALUE
    );

The largest possible value for a BIGINT UNSIGNED column is 18446744073709551615, but the statement INSERT INTO t VALUES (18446744073709551615); would fail, even though the same statement succeeded were t not a partitioned table.

In other words, MAXVALUE was treated as being equal to the greatest possible value, rather than as a least upper bound. (Bug#29258)

Replication: INSERT_ID was not written to the binary log for inserts into BLACKHOLE tables. (Bug#35178)

Replication: When using statement-based replication and a DELETE, UPDATE, or INSERT ... SELECT statement using a LIMIT clause is encountered, a warning that the statement is not safe to replicate in statement mode is now issued; when using MIXED mode, the statement is now replicated using the row-based format. (Bug#34768)

Replication: mysqlbinlog did not output the values of auto_increment_increment and auto_increment_offset when both were equal to their default values (for both of these variables, the default is 1). This meant that a binary log recorded by a client using the defaults for both variables and then replayed on another client using its own values for either or both of these variables produced erroneous results. (Bug#34732)

See also Bug#31168

Replication: A CHANGE MASTER statement with no MASTER_HEARTBEAT_PERIOD option failed to reset the heartbeat period to its default value. (Bug#34686)

Replication: SHOW SLAVE STATUS failed when slave I/O was about to terminate. (Bug#34305)

Replication: The character sets and collations used for constant identifiers in stored procedures were not replicated correctly. (Bug#34289)

Replication: mysqlbinlog from a 5.1 or later MySQL distribution could not read binary logs generated by a 4.1 server when the logs contained LOAD DATA INFILE statements. (Bug#34141)

This regression was introduced by Bug#32407

Replication: A CREATE USER, DROP USER, or RENAME USER statement that fails on the master, or that is a duplicate of any of these statements, is no longer written to the binlog; previously, either of these occurrences could cause the slave to fail.

(Bug#33862)

See also Bug#29749

Replication: SHOW BINLOG EVENTS could fail when the binlog contained one or more events whose size was close to the value of max_allowed_packet. (Bug#33413)

Replication: mysqlbinlog failed to release all of its memory after terminating abnormally. (Bug#33247)

Replication: When a stored routine or trigger, running on a master that used MySQL 5.0 or MySQL 5.1.11 or earlier, performed an insert on an AUTO_INCREMENT column, the INSERT_ID value was not replicated correctly to a slave running MySQL 5.1.12 or later (including any MySQL 6.0 release). (Bug#33029)

See also Bug#19630

Replication: The error message generated due to lack of a default value for an extra column was not sufficiently informative. (Bug#32971)

Replication: When a user variable was used inside an INSERT statement, the corresponding binlog event was not written to the binlog correctly. (Bug#32580)

Replication: When using row-based replication, deletes from a table with a foreign key constraint failed on the slave. (Bug#32468)

Replication: The --base64-output option for mysqlbinlog was not honored for all types of events. This interfered in some cases with performing point-in-time recovery. (Bug#32407)

Replication: SQL statements containing comments using -- syntax were not replayable by mysqlbinlog, even though such statements replicated correctly. (Bug#32205)

Replication: When using row-based replication from a master running MySQL 6.0.3 or earlier to a slave running 6.0.4 or later, updates of integer columns failed on the slave with Error in Unknown event: row application failed. (Bug#31583)

This regression was introduced by Bug#21842

Replication: Replicating write, update, or delete events from a master running MySQL 5.1.15 or earlier to a slave running 5.1.16 or later caused the slave to crash. (Bug#31581)

Replication: When using row-based replication, the slave stopped when attempting to delete non-existent rows from a slave table without a primary key. In addition, no error was reported when this occurred. (Bug#31552)

Replication: Errors due to server ID conflicts were reported only in the slave's error log; now these errors are also shown in the Server_IO_State column in the output of SHOW SLAVE STATUS. (Bug#31316)

Replication: STOP SLAVE did not stop connection attempts properly. If the IO slave thread was attempting to connect, STOP SLAVE waited for the attempt to finish, sometimes for a long period of time, rather than stopping the slave immediately. (Bug#31024)

See also Bug#30932

Replication: Issuing a DROP VIEW statement caused replication to fail if the view did not actually exist. (Bug#30998)

Replication: The effects of scheduled events were not always correctly reproduced on the slave when using row-based replication. (Bug#29020)

Replication: Setting server_id did not update its value for the current session. (Bug#28908)

Replication: Some older servers wrote events to the binary log using different numbering from what is currently used, even though the file format number in the file is the same. Slaves running MySQL 5.1.18 and later could not read these binary logs properly. Binary logs from these older versions now are recognized and event numbers are mapped to the current numbering so that they can be interpreted properly. (Bug#27779, Bug#32434)

This regression was introduced by Bug#22583

Replication: MASTER_POS_WAIT() did not return NULL when the server was not a slave. (Bug#26622)

Replication: The inspecific error message Wrong parameters to function register_slave resulted when START SLAVE failed to register on the master due to excess length of any the slave server options --report-host, --report-user, or --report-password. An error message specific to each of these options is now returned in such cases. The new error messages are:

(Bug#22989)

See also Bug#19328

Replication: PURGE BINARY LOGS TO and PURGE BINARY LOGS BEFORE did not handle missing binary log files correctly or in the same way. Now for both of these statements, if any files listed in the .index file are missing from the filesystem, the statement fails with an error.

API: When the language option was not set correctly, API programs calling mysql_server_init() crashed. This issue was observed only on Windows platforms. (Bug#31868)

Corrected a typecast involving bool on Mac OS X 10.5 (Leopard), which evaluated differently from earlier Mac OS X versions. (Bug#38217)

Replicating a Falcon table that contained a TEXT or BLOB column would fail during a DELETE operation with the error HA_ERR_END_OF_FILE. (Bug#36468)

Following a server crash, recovery of Falcon tables containing BLOB or TEXT columns could lose data. (Bug#35688)

Manually replacing a binary log file with a directory having the same name caused an error that was not handled correctly. (Bug#35675)

Using LOAD DATA INFILE with a view could crash the server. (Bug#35469)

Selecting from INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS could cause a server crash. (Bug#35406)

See also Bug#35108

For a TEMPORARY table, DELETE with no WHERE clause could fail when preceded by DELETE statements with a WHERE clause. (Bug#35392)

In some cases, when too many clients tried to connect to the server, the proper SQLSTATE code was not returned. (Bug#35289)

Memory-allocation failures for attempts to set key_buffer_size to large values could result in a server crash. (Bug#35272)

When using row-based replication, a slave could crash at startup because it received a row-based replication event that InnoDB could not handle due to an incorrect test of the query string provided by MySQL, which was NULL for row-based replication events. (Bug#35226)

Queries could return different results depending on whether ORDER BY columns were indexed. (Bug#35206)

When a view containing a reference to DUAL was created, the reference was removed when the definition was stored, causing some queries against the view to fail with invalid SQL syntax errors. (Bug#35193)

SELECT ... FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS caused the server to crash if the table referenced by a foreign key had been dropped. This issue was observed on Windows platforms only. (Bug#35108)

See also Bug#35406

Debugging symbols were missing for some executables in Windows binary distributions. (Bug#35104)

Non-connection threads were being counted in the value of the Max_used_connections status variable. (Bug#35074)

A query that performed a ref_or_null join where the second table used a key having one or columns that could be NULL and had a column value that was NULL caused the server to crash. (Bug#34945)

This regression was introduced by Bug#12144

For some queries, the optimizer used an ordered index scan for GROUP BY or DISTINCT when it was supposed to use a loose index scan, leading to incorrect results. (Bug#34928)

Creating a foreign key on an InnoDB table that was created with an explicit AUTO_INCREMENT value caused that value to be reset to 1. (Bug#34920)

mysqldump failed to return an error code when using the --master-data option without binary logging being enabled on the server. (Bug#34909)

Under some circumstances, the value of mysql_insert_id() following a SELECT ... INSERT statement could return an incorrect value. This could happen when the last SELECT ... INSERT did not involve an AUTO_INCREMENT column, but the value of mysql_insert_id() was changed by some previous statements. (Bug#34889)

Logging to the progress tables used by BACKUP DATABASE and RESTORE caused a server crash. (Bug#34858)

Table and database names were mixed up in some places of the subquery transformation procedure. This could affect debugging trace output and further extensions of that procedure. (Bug#34830)

If fsync() returned ENOLCK, InnoDB could treat this as fatal and cause abnormal server termination. InnoDB now retries the operation. (Bug#34823)

CREATE SERVER and ALTER SERVER could crash the server if out-of-memory conditions occurred. (Bug#34790)

DROP SERVER does not release memory cached for server structures created by CREATE SERVER, so repeated iterations of these statements resulted in a memory leak. FLUSH PRIVILEGES now releases the memory allocated for CREATE SERVER. (Bug#34789)

A malformed URL used for a FEDERATED table's CONNECTION option value in a CREATE TABLE statement was not handled correctly and could crash the server. (Bug#34788)

Queries such as SELECT ROW(1, 2) IN (SELECT t1.a, 2) FROM t1 GROUP BY t1.a (combining row constructors and subqueries in the FROM clause) could lead to assertion failure or unexpected error messages. (Bug#34763)

Using NAME_CONST() with a negative number and an aggregate function caused MySQL to crash. This could also have a negative impact on replication. (Bug#34749)

A memory-handling error associated with use of GROUP_CONCAT() in subqueries could result in a server crash. (Bug#34747)

For an indexed integer column col_name and a value N that is one greater than the maximum value allowed for the data type of col_name, conditions of the form WHERE col_name < N failed to return rows where the value of col_name is N - 1. (Bug#34731)

A server running with the --debug option could attempt to dereference a null pointer when opening tables, resulting in a crash. (Bug#34726)

Assigning an “incremental” value to the debug system variable did not add the new value to the current value. For example, if the current debug value was 'T', the statement SET debug = '+P' resulted in a value of 'P' rather than the correct value of 'P:T'. (Bug#34678)

For debug builds, reading from INFORMATION_SCHEMA.TABLES or INFORMATION_SCHEMA.COLUMNS could cause assertion failures. This could happen under rare circumstances when INFORMATION_SCHEMA fails to get information about a table (for example, when a connection is killed). (Bug#34656)

Executing a TRUNCATE statement on a table having both a foreign key reference and a DELETE trigger crashed the server. (Bug#34643)

Some subqueries using an expression that included an aggregate function could fail or in some cases lead to a crash of the server. (Bug#34620)

Dangerous pointer arithmetic crashed the server on some systems. (Bug#34598)

Creating a view inside a stored procedure could lead to a crash of the MySQL Server. (Bug#34587)

A server crash could occur if INFORMATION_SCHEMA tables built in memory were swapped out to disk during query execution. (Bug#34529)

CAST(AVG(arg) AS DECIMAL) produced incorrect results for non-DECIMAL arguments. (Bug#34512)

The per-thread debugging settings stack was not being deallocated before thread termination, resulting in a stack memory leak. (Bug#34424)

Client applications could not connect to the server on Windows Vista because the server was creating an IPv6-only TCP/IP socket. (Bug#34381)

Executing an ALTER VIEW statement on a table crashed the server. (Bug#34337)

For InnoDB, exporting and importing a table could corrupt TINYBLOB columns, and a subsequent ALTER TABLE could corrupt TINYTEXT columns as well. (Bug#34300)

On Windows, client programs generated assertion failures. (Bug#34298)

DEFAULT 0 was not allowed for the YEAR data type. (Bug#34274)

Under some conditions, a SET GLOBAL innodb_commit_concurrency or SET GLOBAL innodb_autoextend_increment statement could fail. (Bug#34223)

mysqldump attempts to set the character_set_results system variable after connecting to the server. This failed for pre-4.1 servers that have no such variable, but mysqldump did not account for this and 1) failed to dump database contents; 2) failed to produce any error message alerting the user to the problem. (Bug#34192)

Use of stored functions in the WHERE clause for SHOW OPEN TABLES caused a server crash. (Bug#34166)

Compilation failed on Solaris for the ARCHIVE storage engine due to inclusion of getopt.h in the ARCHIVE code. (Bug#34094)

Updates of floating-point columns in FEDERATED tables could produce incorrect results. (Bug#34015)

For a FEDERATED table with an index on a nullable column, accessing the table could crash a server, return an incorrect result set, or return ERROR 1030 (HY000): Got error 1430 from storage engine. (Bug#33946)

Passing anything other than a integer to a LIMIT clause in a prepared statement would fail. (This limitation was introduced to avoid replication problems; for example, replicating the statement with a string argument would cause a parse failure in the slave). Now, arguments to the LIMIT clause are converted to integer values, and these converted values are used when logging the statement. (Bug#33851)

An internal buffer in mysql was too short. Overextending it could cause stack problems or segmentation violations on some architectures. (This is not a problem that could be exploited to run arbitrary code.) (Bug#33841)

A query using WHERE (column1='string1' AND column2=constant1) OR (column1='string2' AND column2=constant2), where col1 used a binary collation and string1 matched string2 except for case, failed to match any records even when matches were found by a query using the equivalent clause WHERE column2=constant1 OR column2=constant2. (Bug#33833)

Large unsigned integers were improperly handled for prepared statements, resulting in truncation or conversion to negative numbers. (Bug#33798)

Reuse of prepared statements could cause a memory leak in the embedded server. (Bug#33796)

The server crashed when executing a query that had a subquery containing an equality X=Y where Y referred to a named select list expression from the parent select. The server crashed when trying to use the X=Y equality for ref-based access. (Bug#33794)

Some queries using a combination of IN, CONCAT(), and an implicit type conversion could return an incorrect result. (Bug#33764)

In some cases a query that produced a result set when using ORDER BY ASC did not return any results when this was changed to ORDER BY DESC. (Bug#33758)

Disabling concurrent inserts caused some cacheable queries not to be saved in the query cache. (Bug#33756)

The UPDATE statement allowed NULL to be assigned to NOT NULL columns (the default data type value was assigned). An error occurs now. (Bug#33699)

ORDER BY ... DESC sorts could produce misordered results. (Bug#33697)

Use of uninitialized memory for filesort in a subquery caused a server crash. (Bug#33675)

The WEIGHT_STRING() function returned incorrect results for column values when earlier column values were NULL. (Bug#33663)

The server could crash when REPEAT or another control instruction was used in conjunction with labels and a LEAVE instruction. (Bug#33618)

The parser allowed control structures in compound statements to have mismatched beginning and ending labels. (Bug#33618)

make_binary_distribution passed the --print-libgcc-file option to the C compiler, but this does not work with the ICC compiler. (Bug#33536)

Threads created by the event scheduler were incorrectly counted against the max_connections thread limit, which could lead to client lockout. (Bug#33507)

Dropping a function after dropping the function's creator could cause the server to crash. (Bug#33464)

For the latin2_czech_cs collation, the primary weights for all variants of capital letters U and O were incorrect (were not equal to the corresponding small letters). (Bug#33452)

Certain combinations of views, subselects with outer references and stored routines or triggers could cause the server to crash. (Bug#33389)

SET GLOBAL myisam_max_sort_file_size=DEFAULT set myisam_max_sort_file_size to an incorrect value. (Bug#33382)

See also Bug#31177

ENUM- or SET-valued plugin variables could not be set from the command line. (Bug#33358)

If the mysql database was named in the BACKUP DATABASE statement, the backup operation hung. (Bug#33355)

Loading plugins via command-line options to mysqld could cause an assertion failure. (Bug#33345)

SLEEP(0) failed to return on 64-bit Mac OS X due to a bug in pthread_cond_timedwait(). (Bug#33304)

CREATE TABLE ... SELECT created tables that for date columns used the obsolete Field_date type instead of Field_newdate. (Bug#33256)

For MyISAM tables, CHECK TABLE (non-QUICK) and any form of REPAIR TABLE incorrected treated rows as corrupted under the combination of the following conditions:

This problem affected CHECK TABLE, REPAIR TABLE, OPTIMIZE TABLE, ALTER TABLE. CHECK TABLE reported and marked the table as crashed if any row was present that fulfilled the third condition. The other statements deleted these rows. (Bug#33222)

The error message was vague for attempts to drop a Falcon tablespace that contained tables. Now the message Tablespace busy is returned. (Bug#33216)

When creating temporary tables within Falcon, the tables are automatically created in the FALCON_TEMPORARY tablespace. If you specify an alternate tablespace to the CREATE TABLE statement a warning will now be issued to that effect. (Bug#33211)

Granting the UPDATE privilege on one column of a view caused the server to crash. (Bug#33201)

For DECIMAL columns used with the ROUND(X,D) or TRUNCATE(X,D) function with a non-constant value of D, adding an ORDER BY for the function result produced misordered output. (Bug#33143)

See also Bug#33402, Bug#30617

Some valid SELECT statements could not be used as views due to incorrect column reference resolution. (Bug#33133)

The weight for supplementary Unicode characters should be 0xFFFD, but the WEIGHT_STRING() function returned 0x0DC6 instead. (Bug#33077)

The CSV engine did not honor update requests for BLOB columns when the new column value had the same length as the value to be updated. (Bug#33067)

After receiving a SIGHUP signal, the server could crash, and user-specified log options were ignored when reopening the logs. (Bug#33065)

Repeatedly executing a query with a semi-join subquery could cause a server crash. (Bug#33062)

The fix for Bug#11230 and Bug#26215 introduced a significant input-parsing slowdown for the mysql client. This has been corrected. (Bug#33057)

When MySQL was built with OpenSSL, the SSL library was not properly initialized with information of which endpoint it was (server or client), causing connection failures. (Bug#33050)

Under some circumstances a combination of aggregate functions and GROUP BY in a SELECT query over a view could lead to incorrect calculation of the result type of the aggregate function. This in turn could lead to incorrect results, or to crashes on debug builds of the server. (Bug#33049)

The new index condition pushdown optimization could cause a server crash when used with the range access method over an InnoDB table. (Bug#33033)

For DISTINCT queries, 4.0 and 4.1 stopped reading joined tables as soon as the first matching row was found. However, this optimzation was lost in MySQL 5.0, which instead read all matching rows. This fix for this regression may result in a major improvement in performance for DISTINCT queries in cases where many rows match. (Bug#32942)

Repeated creation and deletion of views within prepared statements could eventually crash the server. (Bug#32890)

See also Bug#34587

The correct data type for a NULL column resulting from a UNION could be determined incorrectly in some cases: 1) Not correctly inferred as NULL depending on the number of selects; 2) Not inferred correctly as NULL if one select used a subquery. (Bug#32848)

For queries containing GROUP_CONCAT(DISTINCT col_list ORDER BY col_list), there was a limitation that the DISTINCT columns had to be the same as ORDER BY columns. Incorrect results could be returned if this was not true. (Bug#32798)

Incorrect assertions could cause a server crash for DELETE triggers for transactional tables. (Bug#32790)

SHOW EVENTS and selecting from the INFORMATION_SCHEMA.EVENTS table failed if the current database was INFORMATION_SCHEMA. (Bug#32775)

In some cases where setting a system variable failed, no error was sent to the client, causing the client to hang. (Bug#32757)

Enabling the PAD_CHAR_TO_FULL_LENGTH SQL mode caused privilege-loading operations (such as FLUSH PRIVILEGES) to include trailing spaces from grant table values stored in CHAR columns. Authentication for incoming connections failed as a result. Now privilege loading does not include trailing spaces, regardless of SQL mode. (Bug#32753)

Use of the cp932 character set with CAST() in an ORDER BY clause could cause a server crash. (Bug#32726)

The SHOW ENGINE INNODB STATUS and SHOW ENGINE INNODB MUTEX statements incorrectly required the SUPER privilege rather than the PROCESS privilege. (Bug#32710)

Inserting strings with a common prefix into a table that used the ucs2 character set corrupted the table. (Bug#32705)

A subquery using an IS NULL check of a column defined as NOT NULL in a table used in the FROM clause of the outer query produced an invalid result. (Bug#32694)

Specifying a non-existent column for an INSERT DELAYED statement caused a server crash rather than producing an error. (Bug#32676)

Tables in the mysql database that stored the current sql_mode value as part of stored program definitions were not updated with newer mode values (NO_ENGINE_SUBSTITUTION, PAD_CHAR_TO_FULL_LENGTH). This causes various problems defining stored programs if those modes were included in the current sql_mode value. (Bug#32633)

Use of CLIENT_MULTI_QUERIES caused libmysqld to crash. (Bug#32624)

A SELECT ... GROUP BY bit_column query failed with an assertion if the length of the BIT column used for the GROUP BY was not an integer multiple of 8. (Bug#32556)

A view created with a string literal for one of the columns picked up the connection character set, but not the collation. Comparison to that field therefore used the default collation for that character set, causing an error if the connection collation was not compatible with the default collation. The problem was caused by text literals in a view being dumped with a character set introducer even when this was not necessary, sometimes leading to a loss of collation information. Now the character set introducer is dumped only if it was included in the original query. (Bug#32538)

See also Bug#21505

Using SELECT INTO OUTFILE with 8-bit ENCLOSED BY characters led to corrupted data when the data was reloaded using LOAD DATA INFILE. This was because SELECT INTO OUTFILE failed to escape the 8-bit characters. (Bug#32533)

For FLUSH TABLES WITH READ LOCK, the server failed to properly detect write-locked tables when running with low-priority updates, resulting in a crash or deadlock. (Bug#32528)

Queries using LIKE on tables having indexed CHAR columns using either of the eucjpms or ujis character sets did not return correct results. (Bug#32510)

A query of the form SELECT @user_variable := constant AS alias FROM table GROUP BY alias WITH ROLLUP crashed the server. (Bug#32482)

Sending several KILL QUERY statements to target a connection running SELECT SLEEP() could freeze the server. (Bug#32436)

ssl-cipher values in option files were not being read by libmysqlclient. (Bug#32429)

Repeated execution of a query containing a CASE expression and numerous AND and OR relations could crash the server. The root cause of the issue was determined to be that the internal SEL_ARG structure was not properly initialized when created. (Bug#32403)

Referencing within a subquery an alias used in the SELECT list of the outer query was incorrectly permitted. (Bug#32400)

If a global read lock acquired with FLUSH TABLES WITH READ LOCK was in effect, executing ALTER TABLE could cause a server crash. (Bug#32395)

utf16 columns allowed incorrect Unicode characters inserted through conversion from another Unicode character set. (Bug#32393)

An ORDER BY query on a view created using a FEDERATED table as a base table caused the server to crash. (Bug#32374)

The mysqldump utility did not print enough version information about itself at the top of its output. The output now shows the same information as mysqldump invoked with the -V option, namely the mysqldump version number, the MySQL server version, and the distribution. (Bug#32350)

Comparison of a BIGINT NOT NULL column with a constant arithmetic expression that evaluated to NULL mistakenly caused the error Column '...' cannot be null (error 1048). (Bug#32335)

Assigning a 65,536-byte string to a TEXT column (which can hold a maximum of 65,535 bytes) resulted in truncation without a warning. Now a truncation warning is generated. (Bug#32282)

The LAST_DAY() function returns a DATE value, but internally the value did not have the time fields zeroed and calculations involving the value could return incorrect results. (Bug#32270)

MIN() and MAX() could return incorrect results when an index was present if a loose index scan was used. (Bug#32268)

Executing a prepared statement associated with a materialized cursor sent to the client a metadata packet with incorrect table and database names. The problem occurred because the server sent the the name of the temporary table used by the cursor instead of the table name of the original table.

The same problem occured when selecting from a view, in which case the name of the table name was sent, rather than the name of the view. (Bug#32265)

Memory corruption could occur due to large index map in Range checked for each record status reported by EXPLAIN SELECT. The problem was based in an incorrectly calculated length of the buffer used to store a hexadecimal representation of an index map, which could result in buffer overrun and stack corruption under some circumstances. (Bug#32241)

Various test program cleanups were made: 1) mytest and libmysqltest were removed. 2) bug25714 displays an error message when invoked with incorrect arguments or the --help option. 3) mysql_client_test exits cleanly with a proper error status. (Bug#32221)

The default grant tables on Windows contained information for host production.mysql.com, which should not be there. (Bug#32219)

For comparisons of the form date_col OP datetime_const (where OP is =, <, >, <=, or >=), the comparison is done using DATETIME values, per the fix for Bug#27590. However that fix caused any index on date_col not to be used and compromised performance. Now the index is used again. (Bug#32198)

DATETIME arguments specified in numeric form were treated by DATE_ADD() as DATE values. (Bug#32180)

When configure was run with --with-libevent, libevent was not linked statically with mysqld, preventing mysqld from being run with a debugger. (Bug#32156)

InnoDB adaptive hash latches could be held too long, resulting in a server crash. This fix may also provide significant performance improvements on systems on which many queries using filesorts with temporary tables are being performed. (Bug#32149)

Killing a statement could lead to a race condition in the server. (Bug#32148)

String-to-double conversion was performed differently when the prepared-statement protocol was used from when it was not. (Bug#32095)

With lower_case_table_names set, CREATE TABLE LIKE was treated differently by libmysqld than by the non-embedded server. (Bug#32063)

On Windows, mysqltest_embedded.exe did not properly execute the send command. (Bug#32044)

Within a subquery, UNION was handled differently than at the top level, which could result in incorrect results or a server crash. (Bug#32036, Bug#32051)

HOUR(), MINUTE(), and SECOND() could return non-zero values for DATE arguments. (Bug#31990)

A variable named read_only could be declared even though that is a reserved word. (Bug#31947)

On Windows, the build process failed with four parallel build threads. (Bug#31929)

Changing the SQL mode to cause dates with “zero” parts to be considered invalid (such as '1000-00-00') could result in indexed and non-indexed searches returning different results for a column that contained such dates. (Bug#31928)

The server used unnecessarily large amounts of memory when user variables were used as an argument to CONCAT() or CONCAT_WS(). (Bug#31898)

Queries testing numeric constants containing leading zeroes against ZEROFILL columns were not evaluated correctly. (Bug#31887)

mysql-test-run.pl sometimes set up test scenarios in which the same port number was passed to multiple servers, causing one of them to be unable to start. (Bug#31880)

Using ORDER BY led to the wrong result when using the ARCHIVE on a table with a BLOB when the table cache was full. The table could also be reported as crashed after the query had completed, even though the table data was intact. (Bug#31833)

Name resolution for correlated subqueries and HAVING clauses failed to distinguish which of two was being performed when there was a reference to an outer aliased field. This could result in error messages about a HAVING clause for queries that had no such clause. (Bug#31797)

If an error occurred during file creation, the server sometimes did not remove the file, resulting in an unused file in the filesystem. (Bug#31781)

The mysqld crash handler failed on Windows. (Bug#31745)

mysqlslap failed to commit after the final record load. (Bug#31704)

ucs2 does not work as a client character set, but attempts to use it as such were not rejected. Now character_set_client cannot be set to ucs2. This also affects statements such as SET NAMES and SET CHARACTER SET. (Bug#31615)

The server returned the error message Out of memory; restart server and try again when the actual problem was that the sort buffer was too small. Now an appropriate error message is returned in such cases. (Bug#31590)

For a table that had been opened with HANDLER and marked for reopening after being closed with FLUSH TABLES, DROP TABLE did not properly discard the handler. (Bug#31397)

A table having an index that included a BLOB or TEXT column, and that was originally created with a MySQL server using version 4.1 or earlier, could not be opened by a 5.1 or later server. (Bug#31331)

The -, *, and / operators and the functions POW() and EXP() could misbehave when used with floating-point numbers. Previously they might return +INF, -INF, or NaN in cases of numeric overflow (including that caused by division by zero) or when invalid arguments were used. Now NULL is returned in all such cases. (Bug#31236)

The mysql_change_user() C API function caused global Com_xxx status variable values to be incorrect. (Bug#31222)

When sorting privilege table rows, the server treated escaped wildcard characters (\% and \_) the same as unescaped wildcard characters (% and _), resulting in incorrect row ordering. (Bug#31194)

Server variables could not be set to their current values on Linux platforms. (Bug#31177)

See also Bug#6958

Data in BLOB or GEOMETRY columns could be cropped when performing a UNION query. (Bug#31158)

The server crashed in the parser when running out of memory. Memory handling in the parser has been improved to gracefully return an error when out-of-memory conditions occur in the parser. (Bug#31153)

MySQL declares a UNIQUE key as a PRIMARY key if it doesn't have NULL columns and is not a partial key, and the PRIMARY key must alway be the first key. However, in some cases, a non-first key could be reported as PRIMARY, leading to an assert failure by InnoDB. This is fixed by correcting the key sort order. (Bug#31137)

Many nested subqueries in a single query could led to excessive memory consumption and possibly a crash of the server. (Bug#31048)

An assertion failure occurred for queries containing two subqueries if both subqueries were evaluated using a semi-join strategy. (Bug#31040)

On Windows, SHOW PROCESSLIST could display process entries with a State value of *** DEAD ***. (Bug#30960)

ROUND(X,D) or TRUNCATE(X,D) for non-constant values of D could crash the server if these functions were used in an ORDER BY that was resolved using filesort. (Bug#30889)

Resetting the query cache by issuing a SET GLOBAL query_cache_size=0 statement caused the server to crash if it concurrently was saving a new result set to the query cache. (Bug#30887)

Manifest problems prevented MySQLInstanceConfig.exe from running on Windows Vista. (Bug#30823)

The optimizer incorrectly optimized conditions out of the WHERE clause in some queries involving subqueries and indexed columns. (Bug#30788)

If an alias was used to refer to the value returned by a stored function within a subselect, the outer select recognized the alias but failed to retrieve the value assigned to it in the subselect. (Bug#30787)

Improper calculation of CASE expression results could lead to value truncation. (Bug#30782)

The thread_handling system variable was treated as having a SESSION value and as being settable at runtime. Now it has only a GLOBAL read-only value. (Bug#30651)

If the optimizer used a multi-read-range access method for index lookups, incorrect results could occur for rows that contained any of the BLOB or TEXT data types. (Bug#30622)

Binary logging for a stored procedure differed depending on whether or not execution occurred in a prepared statement. (Bug#30604)

When casting a string value to an integer, cases where the input string contained a decimal point and was long enough to overrun the unsigned long long type were not handled correctly. The position of the decimal point was not taken into account which resulted in miscalculated numbers and incorrect truncation to appropriate SQL data type limits. (Bug#30453)

Replication of LOAD DATA INFILE could fail when read_buffer_size was larger than max_allowed_packet. (Bug#30435)

With libmysqld, use of prepared statements and the query cache at the same time caused problems. (Bug#30430)

For CREATE ... SELECT ... FROM, where the resulting table contained indexes, adding SQL_BUFFER_RESULT to the SELECT part caused index corruption in the table. (Bug#30384)

An orphaned PID file from a no-longer-running process could cause mysql.server to wait for that process to exit even though it does not exist. (Bug#30378)

The optimizer made incorrect assumptions about the value of the is_member value for user-defined functions, sometimes resulting in incorrect ordering of UDF results. (Bug#30355)

The Table_locks_waited waited variable was not incremented in the cases that a lock had to be waited for but the waiting thread was killed or the request was aborted. (Bug#30331)

Simultaneous ALTER TABLE statements for BLACKHOLE tables caused 100% CPU us