Functionality added or changed:
Incompatible change: The prepared_stmt_count system variable has been converted to the Prepared_stmt_count global status variable (viewable with the SHOW GLOBAL STATUS statement). (Bug#23159)
NDB Cluster: Setting the configuration parameter LockPagesInMainMemory had no effect. (Bug#24461)
NDB Cluster: It is now possible to create a unique hashed index on a column that is not defined as NOT NULL. Note that this change applies only to tables using the NDB storage engine.
Unique indexes on columns in NDB tables do not store null values because they are mapped to primary keys in an internal index table (and primary keys cannot contain nulls).
Normally, an additional ordered index is created when one creates unique indexes on NDB table columns; this can be used to search for NULL values. However, if USING HASH is specified when such an index is created, no ordered index is created.
The reason for permitting unique hash indexes with null values is that, in some cases, the user wants to save space if a large number of records are pre-allocated but not fully initialized. This also assumes that the user will not try to search for null values. Since MySQL does not support indexes that are not allowed to be searched in some cases, the NDB storage engine uses a full table scan with pushed conditions for the referenced index columns to return the correct result.
Note that a warning is returned if one creates a unique nullable hash index, since the query optimizer should be provided a hint not to use it with NULL values if this can be avoided.
In MySQL 5.0.13 and up, InnoDB rolls back only the last statement on a transaction timeout. A new option, --innodb_rollback_on_timeout, causes InnoDB to abort and roll back the entire transaction if a transaction timeout occurs (the same behavior as before MySQL 5.0.13). (Bug#24200)
DROP TRIGGER now supports an IF EXISTS clause. (Bug#23703)
The Com_create_user status variable was added (for counting CREATE USER statements). (Bug#22958)
The --memlock option relies on system calls that are unreliable on some operating systems. If a crash occurs, the server now checks whether --memlock was specified and if so issues some information about possible workarounds. (Bug#22860)
The bundled yaSSL library was upgraded to version 1.5.0.
If the user specified the server options --max-connections= or N--table-open-cache=, a warning would be given in some cases that some values were recalculated, with the result that M--table-open-cache could be assigned greater value.
It should be noted that, in such cases, both the warning and the increase in the --table-open-cache value were completely harmless. Note also that it is not possible for the MySQL Server to predict or to control limitations on the maximum number of open files, since this is determined by the operating system.
The recalculation code has now been fixed to ensure that the value of --table-open-cache is no longer increased automatically, and that a warning is now given only if some values had to be decreased due to operating system limits.
NDB Cluster: The HELP command in the Cluster management client now provides command-specific help. For example, HELP RESTART in ndb_mgm provides detailed information about the START command. (Bug#19620)
NDB Cluster: Added the --bind-address option for ndbd. This allows a data node process to be bound to a specific network interface. (Bug#22195)
NDB Cluster: The Ndb_number_of_storage_nodes system variable was renamed to Ndb_number_of_data_nodes. (Bug#20848)
NDB Cluster: The ndb_config utility now accepts -c as a short form of the --ndb-connectstring option. (Bug#22295)
SHOW STATUS is no longer logged to the slow query log. (Bug#19764)
mysqldump --single-transaction now uses START TRANSACTION /*!40100 WITH CONSISTENT SNAPSHOT */ rather than BEGIN to start a transaction, so that a consistent snapshot will be used on those servers that support it. (Bug#19660)
mysql_upgrade now passes all the parameters specified on the command line to both mysqlcheck and mysql using the upgrade_defaults file. (Bug#20100)
For the CALL statement, stored procedures that take no arguments now can be invoked without parentheses. That is, CALL p() and CALL p are equivalent. (Bug#21462)
Bugs fixed:
NDB Cluster: Sudden disconnection of an SQL or data node could lead to shutdown of data nodes with the error failed ndbrequire. (Bug#24447)
NDB Cluster: ndb_config failed when trying to use 2 management servers and node IDs. (Bug#23887)
NDB Cluster (Cluster APIs): Using BIT values with any of the comparison methods of the NdbScanFilter class caused the cluster's data nodes to fail. (Bug#24503)
NDB Cluster: The failure of a data node failure during a schema operation could lead to additional node failures. (Bug#24752)
NDB Cluster: A committed read could be attempted before a data node had time to connect, causing a timeout error. (Bug#24717)
NDB Cluster (Cluster APIs): Some MGM API function calls could yield incorrect return values in certain cases where the cluster was operating under a very high load, or experienced timeouts in inter-node communications. (Bug#24011)
NDB Cluster: A unique constraint violation was not ignored by an UPDATE IGNORE statement when the constraint violation occurred on a non-primary key. (Bug#18487, Bug#24303)
mysql_fix_privilege_tables did not handle a password containing embedded space or apostrophe characters. (Bug#17700)
Foreign key identifiers for InnoDB tables could not contain certain characters. (Bug#24299)
In some cases, the parser failed to distinguish a user-defined function from a stored function. (Bug#21809)
With innodb_file_per_table enabled, InnoDB displayed incorrect file times in the output from SHOW TABLE STATUS. (Bug#24712)
The stack size for NetWare binaries was increased to 128KB to prevent problems caused by insufficient stack size. (Bug#23504)
Attempting to use a view containing DEFINER information for a non-existent user resulted in an error message that revealed the definer account. Now the definer is revealed only to superusers. Other users receive only an access denied message. (Bug#17254)
mysql_upgrade failed if the --password (or -p) option was given. (Bug#24896)
For a nonexistent table, DROP TEMPORARY TABLE failed with an incorrect error message if read_only was enabled. (Bug#22077)
The code for generating USE statements for binary logging of CREATE PROCEDURE statements resulted in confusing output from mysqlbinlog for DROP PROCEDURE statements. (Bug#22043)
The InnoDB mutex structure was simplified to reduce memory load. (Bug#24386)
The REPEAT() function could return NULL when passed a column for the count argument. (Bug#24947)
Accuracy was improved for comparisons between DECIMAL columns and numbers represented as strings. (Bug#23260)
InnoDB crashed while performing XA recovery of prepared transactions. (Bug#21468)
ROW_COUNT() did not work properly as an argument to a stored procedure. (Bug#23760)
The size of MEMORY tables and internal temporary tables was limited to 4GB on 64-bit Windows systems. (Bug#24052)
For queries that select from a view, the server was returning MYSQL_FIELD metadata inconsistently for view names and table names. For view columns, the server now returns the view name in the table field and, if the column selects from an underlying table, the table name in the org_table field. (Bug#20191)
It was possible to use DATETIME values whose year, month, and day parts were all zeroes but whose hour, minute, and second parts contained nonzero values, an example of such an illegal DATETIME being '0000-00-00 11:23:45'. (Bug#21789)
It was possible to set the backslash character (“\”) as the delimiter character using DELIMITER, but not actually possible to use it as the delimiter. (Bug#21412)
The loose index scan optimization for GROUP BY with MIN or MAX was not applied within other queries, such as CREATE TABLE ... SELECT ..., INSERT ... SELECT ..., or in the FROM clauses of subqueries. (Bug#24156)
ALTER ENABLE KEYS or ALTER TABLE DISABLE KEYS combined with another ALTER TABLE option other than RENAME TO did nothing. In addition, if ALTER TABLE was used on a table having disabled keys, the keys of the resulting table were enabled. (Bug#24395)
Queries using a column alias in an expression as part of an ORDER BY clause failed, an example of such a query being SELECT mycol + 1 AS mynum FROM mytable ORDER BY 30 - mynum. (Bug#22457)
Trailing spaces were not removed from Unicode CHAR column values when used in indexes. This resulted in excessive usage of storage space, and could affect the results of some ORDER BY queries that made use of such indexes.
Note: When upgrading, it is necessary to re-create any existing indexes on Unicode CHAR columns in order to take advantage of the fix. This can be done by using a REPAIR TABLE statement on each affected table.
Warnings were generated when explicitly casting a character to a number (for example, CAST('x' AS SIGNED)), but not for implicit conversions in simple arithmetic operations (such as 'x' + 0). Now warnings are generated in all cases. (Bug#11927)
STR_TO_DATE() returned NULL if the format string contained a space following a non-format character. (Bug#22029)
yaSSL crashed on pre-Pentium Intel CPUs. (Bug#21765)
Selecting into variables sometimes returned incorrect wrong results. (Bug#20836)
Inserting DEFAULT into a column with no default value could result in garbage in the column. Now the same result occurs as when inserting NULL into a NOT NULL column. (Bug#20691)
mysql_fix_privilege_tables.sql altered the table_privs.table_priv column to contain too few privileges, causing loss of the CREATE VIEW and SHOW VIEW privileges. (Bug#20589)
A query with a subquery that references columns of a view from the outer SELECT could return an incorrect result if used from a prepared statement. (Bug#20327)
A server crash occurred when using LOAD DATA to load a table containing a NOT NULL spatial column, when the statement did not load the spatial column. Now a NULL supplied to NOT NULL column error occurs. (Bug#22372)
Unsigned BIGINT values treated as signed values by the MOD() function. (Bug#19955)
Compiling PHP 5.1 with the MySQL static libraries failed on some versions of Linux. (Bug#19817)
The DELIMITER statement did not work correctly when used in an SQL file run using the SOURCE statement. (Bug#19799)
VARBINARY column values inserted on a MySQL 4.1 server had trailing zeroes following upgrade to MySQL 5.0 or later. (Bug#19371)
Constant expressions and some numeric constants used as input parameters to user-defined functions were not treated as constants. (Bug#18761)
Subqueries of the form NULL IN (SELECT ...) returned invalid results. (Bug#8804, Bug#23485)
The --extern option for mysql-test-run.pl did not function correctly. (Bug#24354)
INET_ATON() returned a signed BIGINT value, not an unsigned value. (Bug#21466)
ALTER TABLE statements that performed both RENAME TO and {ENABLE|DISABLE} KEYS operations caused a server crash. (Bug#24089)
myisampack wrote to unallocated memory, causing a crash. (Bug#17951)
Some small double precision numbers (such as 1.00000001e-300) that should have been accepted were truncated to zero. (Bug#22129)
The mysql.server script used the source command, which is less portable than the . command; it now uses . instead. (Bug#24294)
DATE_ADD() requires complete dates with no “zero” parts, but sometimes did not return NULL when given such a date. (Bug#22229)
Using FLUSH TABLES in one connection while another connection is using HANDLER statements caused a server crash. (Bug#21587)
FLUSH LOGS or mysqladmin flush-logs caused a server crash if the binary log was not open. (Bug#17733)
Subqueries for which a pushed-down condition did not produce exactly one key field could cause a server crash. (Bug#24056)
LAST_DAY('0000-00-00') could cause a server crash. (Bug#23653)
Through the C API, the member strings in MYSQL_FIELD for a query that contains expressions may return incorrect results. (Bug#21635)
mysql_affected_rows() could return values different from mysql_stmt_affected_rows() for the same sequence of statements. (Bug#23383)
IN() and CHAR() can return NULL, but did not signal that to the query processor, causing incorrect results for IS NULL operations. (Bug#17047)
A trigger that invoked a stored function could cause a server crash when activated by different client connections. (Bug#23651)
CONCURRENT did not work correctly for LOAD DATA INFILE. (Bug#20637)
Inserting a default or invalid value into a spatial column could fail with Unknown error rather than a more appropriate error. (Bug#21790)
The server could send incorrect column count information to the client for queries that produce a larger number of columns than can fit in a two-byte number. (Bug#19216)
Evaluation of subqueries that require the filesort algorithm were allocating and freeing the sort_buffer_size buffer many times, resulting in slow performance. Now the buffer is allocated once and reused. (Bug#21727)
SQL statements close to the size of max_allowed_packet could produce binary log events larger than max_allowed_packet that could not be read by slave servers. (Bug#19402)
View columns were always handled as having implicit derivation, leading to illegal mix of collation errors for some views in UNION operations. Now view column column derivation comes from the original expression given in the view definition. (Bug#21505)
If elements in a non-top-level IN subquery were accessed by an index and the subquery result set included a NULL value, the quantified predicate that contained the subquery was evaluated to NULL when it should return a non-NULL value. (Bug#23478)
Calculation of COUNT(DISTINCT), AVG(DISTINCT), or SUM(DISTINCT) when they are referenced more than once in a single query with GROUP BY could cause a server crash. (Bug#23184)
For a cast of a DATETIME value containing microseconds to DECIMAL, the microseconds part was truncated without generating a warning. Now the microseconds part is preserved. (Bug#19491)
Metadata for columns calculated from scalar subqueries was limited to integer, double, or string, even if the actual type of the column was different. (Bug#11032)
The result for CAST() when casting a value to UNSIGNED was limited to the maximum signed BIGINT value, not the maximum unsigned value. (Bug#8663)
Using EXPLAIN caused a server crash for queries that selected from INFORMATION_SCHEMA in a subquery in the FROM clause. (Bug#22413)
Invalidating the query cache caused a server crash for INSERT INTO ... SELECT statements that selected from a view. (Bug#20045)
Slave servers would retry the execution of a SQL statement an infinite number of times, ignoring the value SLAVE_TRANSACTION_RETRIES when using the NDB engine. (Bug#16228)
On slave servers, transactions that exceeded the lock wait timeout failed to roll back properly. (Bug#20697)
Changes to character set variables prior to an action on a replication-ignored table were forgotten by slave servers. (Bug#22877)
With lower_case_table_names set to 1, SHOW CREATE TABLE printed incorrect output for table names containing Turkish I (LATIN CAPITAL LETTER I WITH DOT ABOVE). (Bug#20404)
When applying the group_concat_max_len limit, GROUP_CONCAT() could truncate multi-byte characters in the middle. (Bug#23451)
For some problems relating to character set conversion or incorrect string values for INSERT or UPDATE, the server was reporting truncation or length errors instead. (Bug#18908)
NDB Cluster: Data nodes added while the cluster was running in single user mode were all assigned node ID 0, which could later cause multiple node failures. Adding of nodes in single user mode is no longer possible. (Bug#20395)
NDB Cluster: Attempting to create an NDB table on a MySQL with an existing non-Cluster table with the same name in the same database could result in data loss or corruption. MySQL now issues a warning when a SHOW TABLES or other statement causing table discovery finds such a table. (Bug#21378)
NDB Cluster (NDB API): Inacivity timeouts for scans were not correctly handled. (Bug#23107)
NDB Cluster (NDB API): Attempting to read a nonexistent tuple using Commit mode for NdbTransaction::execute() caused node failures. (Bug#22672)
NDB Cluster (NDB API): Scans closed before being executed were still placed in the send queue. (Bug#21941)
NDB Cluster (NDB API): The NdbOperation::getBlobHandle() method, when called with the name of a nonexistent column, caused a segmentation fault. (Bug#21036)
NDB Cluster: A problem with takeover during a system restart caused ordered indexes to be rebuilt incorrectly. (Bug#15303)
NDB Cluster: The ndb_config utility did not perform host lookups correctly when using the --host option. (Bug#17582)
NDB Cluster: The ndb_config utility did not perform host lookups correctly when using the --host option (Bug#17582)
NDB Cluster: The error returned by the cluster when too many nodes were defined did not make clear the nature of the problem. (Bug#19045)
NDB Cluster: ndb_mgm -e show | head would hang after displaying the first 10 lines of output. (Bug#19047)
NDB Cluster: In rare situations with resource shortages, a crash could result from insufficient IndexScanOperations. (Bug#19198)
NDB Cluster: ndb_restore did not always make clear that it had recovered successfully from temporary errors while restoring a cluster backup. (Bug#19651)
NDB Cluster: Error messages given when trying to make online changes parameters such as NoOfReplicas thast can only be changed via a complete shutdown and restart of the cluster did not indicate the true nature of the problem. (Bug#19787)
NDB Cluster: Following the restart of an MGM node, the Cluster management client did not automatically reconnect. (Bug#19873)
NDB Cluster: In some cases where SELECT COUNT(*) from an NDB table should have yielded an error, MAX_INT was returned instead. (Bug#19914)
NDB Cluster (NDB API): When multiple processes or threads in parallel performed the same ordered scan with exclusive lock and updating the retrieved records, the scan could skip some records, which were not updated as a result. (Bug#20446)
NDB Cluster: Using an invalid node ID with the management client STOP command could cause ndb_mgm to hang. (Bug#20575)
NDB Cluster: Under some circumstances, local checkpointing would hang, keeping any unstarted nodes from being started. (Bug#20895)
NDB Cluster: Condition pushdown did not work correctly with DATETIME columns. (Bug#21056)
NDB Cluster: When inserting a row into an NDB table with a duplicate value for a non-primary unique key, the error issued would reference the wrong key. (Bug#21072)
NDB Cluster: Cluster logs were not rotated following the first rotation cycle. (Bug#21345)
NDB Cluster: The ndb_mgm management client did not set the exit status on errors, always returning 0 instead. (Bug#21530)
NDB Cluster: Partition distribution keys were updated only for the primary and starting replicas during node recovery. This could lead to node failure recovery for clusters having an odd number of replicas. (Bug#21535)
Note: We recommend values for NumberOfReplicas that are even powers of 2, for best results.
NDB Cluster: The output for the --help option used with NDB executable programs (ndbd, ndb_mgm, ndb_restore, ndb_config, and so on) referred to the Ndb.cfg file, instead of my.cnf. (Bug#21585)
NDB Cluster: The node recovery algorithm was missing a version check for tables in the ALTER_TABLE_COMMITTED state (as opposed to the TABLE_ADD_COMMITTED state, which has the version check). This could cause inconsistent schemas across nodes following node recovery. (Bug#21756)
NDB Cluster: A scan timeout returned Error 4028 (Node failure caused abort of transaction) instead of Error 4008 (Node failure caused abort of transaction...). (Bug#21799)
NDB Cluster: The --help output from NDB binaries did not include file-related options. (Bug#21994)
NDB Cluster: Multiple node restarts in rapid succession could cause a system restart to fail (Bug#22892), or induce a race condition (Bug#23210).
NDB Cluster: If a node restart could not be performed from the REDO log, no node takeover took place. This could cause partitions to be left empty during a system restart. (Bug#22893)
NDB Cluster: INSERT ... ON DUPLICATE KEY UPDATE on an NDB table could lead to deadlocks and memory leaks. (Bug#23200)
NDB Cluster: The management client command ALL DUMP 1000 would cause the cluster to crash if data nodes were connected to the cluster but not yret fully started. (Bug#23203)
NDB Cluster: Cluster backups would fail when there were more than 2048 schema objects in the cluster. (Bug#23499)
NDB Cluster: Restoring a cluster failed if there were any tables with 128 or more columns. (Bug#23502)
If an init_connect SQL statement produced an error, the connection was silently terminated with no error message. Now the server writes a warning to the error log. (Bug#22158)
The internal SQL interpreter of InnoDB placed an unnecessary lock on the supremum record when innodb_locks_unsafe_for_binlog=1. This caused an assertion failure when InnoDB was built with debugging enabled. (Bug#23769)
If a table contains an AUTO_INCREMENT column, inserting into an insertable view on the table that does not include the AUTO_INCREMENT column should not change the value of LAST_INSERT_ID(), because the side effects of inserting default values into columns not part of the view should not be visible. MySQL was incorrectly setting LAST_INSERT_ID() to zero. (Bug#22584)
M % 0NULL, but (M % 0) IS NULL
Within a stored routine, a view definition cannot refer to routine parameters or local variables. However, an error did not occur until the routine was called. Now it occurs during parsing of the routine creation statement. (Bug#20953)
Note: A side effect of this fix is that if you have already created such routines, and error will occur if you execute SHOW CREATE PROCEDURE or SHOW CREATE FUNCTION. You should drop these routines because they are erroneous.
A client library crash was caused by executing a statement such as SELECT * FROM t1 PROCEDURE ANALYSE() using a server side cursor on a table t1 that does not have the same number of columns as the output from PROCEDURE ANALYSE(). (Bug#17039)
mysql did not check for errors when fetching data during result set printing. (Bug#22913)
Adding a day, month, or year interval to a DATE value produced a DATE, but adding a week interval produced a DATETIME value. Now all produce a DATE value. (Bug#21811)
The column default value in the output from SHOW COLUMNS or SELECT FROM INFORMATION_SCHEMA.COLUMNS was truncated to 64 characters. (Bug#23037)
For not-yet-authenticated connections, the Time column in SHOW PROCESSLIST was a random value rather than NULL. (Bug#23379)
The Host column in SHOW PROCESSLIST output was blank when the server was started with the --skip-grant-tables option. (Bug#22728)
The Handler_rollback status variable sometimes was incremented when no rollback had taken place. (Bug#22728)
Within a prepared statement, SELECT (COUNT(*) = 1) (or similar use of other aggregate functions) did not return the correct result for statement re-execution. (Bug#21354)
Lack of validation for input and output TIME values resulted in several problems: SEC_TO_TIME() within subqueries incorrectly clipped large values; SEC_TO_TIME() treated BIGINT UNSIGNED values as signed; only truncation warnings were produced when both truncation and out-of-range TIME values occurred. (Bug#11655, Bug#20927)
Range searches on columns with an index prefix could miss records. (Bug#20732)
With SQL_MODE=TRADITIONAL, MySQL incorrectly aborted on warnings within stored routines and triggers. (Bug#20028)
In mysql, invoking connect or \r with very long db_name or host_name parameters caused buffer overflow. (Bug#20894)
mysqldump --xml produced invalid XML for BLOB data. (Bug#19745)
For a debug server, a reference to an undefined user variable in a prepared statment executed with EXECUTE caused an assertion failure. (Bug#19356)
Within a trigger for a base table, selecting from a view on that base table failed. (Bug#19111)
DELETE IGNORE could hang for foreign key parent deletes. (Bug#18819)
Transient errors in replication from master to slave may trigger multiple Got fatal error 1236: 'binlog truncated in the middle of event' errors on the slave. (Bug#4053)
The value of the warning_count system variable was not being calculated correctly (also affecting SHOW COUNT(*) WARNINGS). (Bug#19024)
InnoDB exhibited thread thrashing with more than 50 concurrent connections under an update-intensive workload. (Bug#22868)
InnoDB showed substandard performance with multiple queries running concurrently. (Bug#15815)
There was a race condition in the InnoDB fil_flush_file_spaces() function. (Bug#24089)
FROM_UNIXTIME() did not accept arguments up to POWER(2,31)-1, which it had previously. (Bug#9191)
Some yaSSL-related memory leaks detected by Valgrind were fixed. (Bug#23981)
If COMPRESS() returned NULL, subsequent invocations of COMPRESS() within a result set or within a trigger also returned NULL. (Bug#23254)
mysql would lose its connection to the server if its standard output was not writable. (Bug#17583)
mysql-test-run did not work correctly for RPM-based installations. (Bug#17194)
The return value from my_seek() was ignored. (Bug#22828)
Use of PREPARE with a CREATE PROCEDURE statement that contained a syntax error caused a server crash. (Bug#21868)
Use of a DES-encrypted SSL certificate file caused a server crash. (Bug#21868)
Column names were not quoted properly for replicated views. (Bug#19736)
InnoDB used table locks (not row locks) within stored functions. (Bug#18077)
Statements such as DROP PROCEDURE and DROP VIEW were written to the binary log too late due to a race condition. (Bug#14262)
MySQL would fail to build on the Alpha platform. (Bug#23256)
The optimizer failed to use equality propagation for BETWEEN and IN predicates with string arguments. (Bug#22753)
The optimizer used the ref join type rather than eq_ref for a simple join on strings. (Bug#22367)
The WITH CHECK OPTION for a view failed to prevent storing invalid column values for UPDATE statements. (Bug#16813)
A literal string in a GROUP BY clause could be interpreted as a column name. (Bug#14019)
Some queries that used MAX() and GROUP BY could incorrectly return an empty result. (Bug#22342)
WITH ROLLUP could group unequal values. (Bug#20825)
Use of a subquery that invoked a function in the column list of the outer query resulted in a memory leak. (Bug#21798)
LIKE searches failed for indexed utf8 character columns. (Bug#20471)
FLUSH INSTANCES in Instance Manager triggered an assertion failure. (Bug#19368)
ALTER TABLE was not able to rename a view. (Bug#14959)
Entries in the slow query log could have an incorrect Rows_examined value. (Bug#12240)
Insufficient memory (myisam_sort_buffer_size) could cause a server crash for several operations on MyISAM tables: repair table, create index by sort, repair by sort, parallel repair, bulk insert. (Bug#23175)
OPTIMIZE TABLE with myisam_repair_threads > 1 could result in MyISAM table corruption. (Bug#8283)
Selecting from a MERGE table could result in a server crash if the underlying tables had fewer indexes than the MERGE table itself. (Bug#22937)
A locking safety check in InnoDB reported a spurious error stored_select_lock_type is 0 inside ::start_stmt() for INSERT ... SELECT statements in innodb_locks_unsafe_for_binlog mode. The safety check was removed. (Bug#10746)
For multiple-table UPDATE statements, storage engines were not notified of duplicate-key errors. (Bug#21381)
Incorrect results could be obtained from re-execution of a parametrized prepared statement or a stored routine with a SELECT that uses LEFT JOIN with a second table having only one row. (Bug#21081)
An UPDATE that referred to a key column in the WHERE clause and activated a trigger that modified the column resulted in a loop. (Bug#20670)
Creating a TEMPORARY table with the same name as an existing table that was locked by another client could result in a lock conflict for DROP TEMPORARY TABLE because the server unnecessarily tried to acquire a name lock. (Bug#21096)
After FLUSH TABLES WITH READ LOCK followed by UNLOCK TABLES, attempts to drop or alter a stored routine failed with an error that the routine did not exist, and attempts to execute the routine failed with a lock conflict error. (Bug#21414)
SHOW VARIABLES truncated the Value field to 256 characters. (Bug#20862)
Instance Manager didn't close the client socket file when starting a new mysqld instance. mysqld inherited the socket, causing clients connected to Instance Manager to hang. (Bug#12751)
Instance Manager had a race condition involving mysqld PID file removal. (Bug#22379)
It was possible for a stored routine with a non-latin1 name to cause a stack overrun. (Bug#21311)
MySQL 5.0.26 introduced an ABI incompatibility, which this release reverts. Programs compiled against 5.0.26 are not compatible with any other version and must be recompiled. (Bug#23427)
InnoDB: Reduced optimization level for Windows 64 builds to handle possible memory overrun. (Bug#19424)