A known limitation of this release:
If you have
InnoDB tables with full-text
search indexes and you are upgrading from MySQL 5.6.10 to a
MySQL version up to and including MySQL 5.6.18, the server
will fail to start after the upgrade (Bug#72079). This bug is
fixed in MySQL 5.6.19. As a workaround, remove full-text
search indexes prior to upgrading and rebuild full-text search
indexes after the upgrade is completed.
It was not possible to upgrade a community RPM to a commercial RPM using rpm -uvh or yum localupdate. To deal with this, the RPM spec file has been updated in MySQL 5.6.11, which has the following consequences:
For a non-upgrade installation (no existing MySQL version installed), it possible to install MySQL using yum.
For upgrades, it is necessary to clean up any earlier MySQL installations. In effect, the update is performed by removing the old installations and installing the new one.
Additional details follow.
For a non-upgrade installation of MySQL 5.6.11, it is possible to install using yum:
yum install MySQL-server-
For upgrades to MySQL 5.6.11, the upgrade is performed by removing the old installation and installing the new one. To do this, use the following procedure:
Remove the existing 5.6.
OLDVERSION is the
version to remove.
rpm -e MySQL-server-
Repeat this step for all installed MySQL RPMs.
Install the new version.
NEWVERSION is the version to
rpm -ivh MySQL-server-
Alternatively, the removal and installation can be done using yum:
yum remove MySQL-server-shell>
yum install MySQL-server-
(Bug #16445097, Bug #16445125, Bug #16587285)
Functionality Added or Changed
GTID_SUBSET() were formerly
libmysqld only when it was built
with replication support. Now these functions are always
available when using this library, regardless of how it was
MySQL no longer uses the default OpenSSL compression. (Bug #16235681)
There is now a distinct error code
for the error sent by the server to a client authenticating with
an expired password.
mysqlcheck has a new
--skip-database option. The
option value is the name of a database (case sensitive) for
which checks should be skipped.
mysql_upgrade uses this option to upgrade the
system tables in the mysql database before
tables in other databases: It upgrade the
mysql database, then all databases except the
mysql database. This avoids problems that can
occur if user tables are upgraded before the system tables.
The only supported value for the
system variable is 1, so this variable is now deprecated.
Setting it to 1 at startup results in a warning. Setting it to a
value other than 1 at startup results in an error and the server
exits. This variable will be removed in a future release.
Switching the MySQL table used by the
interface (using the
@@ notation), was
made more efficient, by reading cached information about the
cache policy to use for each table. This optimization lets you
frequently switch between tables during a session that uses the
memcached interface, without incurring I/O overhead from
examining table metadata each time.
Performance; InnoDB: Performance was improved for operations on tables with many rows that were deleted but not yet purged. The speedup applies mainly to workloads that perform bulk deletes, or updates to the primary key columns, and where the system is busy enough to experience purge lag. (Bug #16138582, Bug #68069)
DROP TABLE statement for a
table using compression
could be slower than necessary, causing a stall for several
seconds. MySQL was unnecessarily decompressing
pages in the
buffer pool related to
the table as part of the
Performance; InnoDB: The I/O routines used when the AIO subsystem were made more efficient, to merge consecutive I/O requests into a single operation. This fix solves a performance issue introduced during the 5.6 development cycle. (Bug #16043841, Bug #67973)
Incompatible Change; Partitioning:
Changes in the
KEY partitioning hashing
functions used with numeric, date and time,
SET columns in MySQL 5.5 makes
tables using partitioning or subpartitioning by
KEY on any of the affected column types and
created on a MySQL 5.5 or later server incompatible with a MySQL
5.1 server. This is because the partition IDs as calculated by a
MySQL 5.5 or later server almost certainly differ from those
calculated by a MySQL 5.1 server for the same table definition
and data as a result of the changes in these functions.
The principal changes in the
implementation in MySQL 5.5 resulting in this issue were as
follows: 1. The hash function used for numeric and date and time
columns changed from binary to character-based. 2. The base used
for hashing of
SET columns changed from
ci characters to binary.
The fix involves adding the capability in MySQL 5.5 and later to
choose which type of hashing to use for
partitioning, which is implemented with a new
ALGORITHM extension to the
BY KEY option for
PARTITION BY KEY ALGORITHM=1
([ causes the
server to use the hashing functions as implemented in MySQL 5.1;
ALGORITHM=2 causes the server to use
the hashing functions from MySQL 5.5 and later.
ALGORITHM=2 is the default. Using the
appropriate value for
ALGORITHM, you can
perform any of the following tasks:
KEY partitioned tables in MySQL
5.5 and later that are compatible with MySQL 5.1, using
CREATE TABLE ... PARTITION BY KEY ALGORITHM=1
KEY partitioned tables that
were created in MySQL 5.5 or later to become compatible with
MySQL 5.1, using
ALTER TABLE ... PARTITION BY KEY
KEY partitioned tables originally
created in MySQL 5.1 to use hashing as in MySQL 5.5 and
ALTER TABLE ... PARTITION BY KEY
Important: After such tables are
upgraded, they cannot be used any longer with MySQL 5.1
unless they are first downgraded again using
TABLE ... PARTITION BY KEY ALGORITHM=1 (...) on a
MySQL server supporting this option.
This syntax is not backward compatible, and causes errors in
older versions of the MySQL server. When generating
CREATE TABLE ...
PARTITION BY KEY statements,
mysqldump brackets any occurrence of
in conditional comments such that it is ignored by a MySQL
server whose version is not at least 5.5.31. An additional
consideration for upgrades is that MySQL 5.6 servers prior to
MySQL 5.6.11 do not ignore the
option in such statements when generated by a MySQL 5.5 server,
due to the that the conditional comments refer to version
5.5.31; in this case, you must edit the dump manually and remove
or comment out the option wherever it occurs before attempting
to load it into a MySQL 5.6.10 or earlier MySQL 5.6 server. This
is not an issue for dumps generated by MySQL 5.6.11 or later
version of mysqldump, where the version used
in such comments is 5.6.11. For more information, see
ALTER TABLE Partition Operations.
As part of this fix, a spurious assertion by
InnoDB that a deleted row had
previously been read, causing the server to assert on delete of
a row that the row was in the wrong partition, was also removed.
(Bug #14521864, Bug #66462, Bug #16093958, Bug #16274455)
References: See also Bug #11759782.
Important Change; Replication
This fix was reverted in MySQL 5.6.12. See the section called “Changes in MySQL 5.6.12 (2013-06-03)”.
Executing a statement that performs an implicit commit but whose
changes are not logged when
gtid_next is set to any value
AUTOMATIC is not permitted. Now in
such cases, the statement fails with an error. This includes the
statements in the following list:
References: See also Bug #16484323.
Important Change; Replication:
The version number reported by mysqlbinlog
--version has been increased
(Bug #15894381, Bug #67643)
Important Note; Replication: Using row-based logging to replicate from a table to a same-named view led to a failure on the slave. Now, when using row-based logging, the target object type is checked prior to performing any DML, and an error is given if the target on the slave is not actually a table.
It remains possible to replicate from a table to a same-named view using statement-based logging.
(Bug #11752707, Bug #43975)
ADD PRIMARY KEY columns are reordered in
ALTER TABLE statement (for
ALTER TABLE t1 ADD PRIMARY KEY(a,b), CHANGE a
a INT AFTER b), the log apply for
UPDATE operations would fail to find rows.
ALTER TABLE operations on
InnoDB tables that added a
KEY using a column prefix could produce an incorrect
ALTER TABLE operations on
InnoDB tables that required a table-copying
operation, other transactions on the table might fail during the
copy. However, if such a transaction issued a partial rollback,
the rollback was treated as a full rollback.
When parsing a delimited search string such as
“abc-def” in a full-text search,
InnoDB now uses the same word delimiters as
This fix improves code readability by addressing naming
inconsistencies for InnoDB
InnoDB: This fix disables a condition for extra splitting of clustered index leaf pages, on compressed tables. Extra page splitting was only done to reserve space for future updates, so that future page splits could be avoided. (Bug #16401801)
InnoDB tables, if a
KEY on a
(or prefix) was empty, index page compression could fail.
Status values in the
innodb_ft_config table would not
intended for internal configuration and should not be used for
statistical information purposes. To avoid confusion, column
values that are intended for internal use have been removed from
innodb_ft_config table. This
fix also removes the
innodb_ft_config table and other
internal full text search-related tables that were
(Bug #16409494, Bug #68502)
Crash recovery would fail with a
!recv_no_log_write assertion when reading a
Improper testing of compatibility between the referencing and
ALTER TABLE ... ADD
FOREIGN key could cause a server exit.
InnoDB: Rollback did not include changes made to temporary tables by read-only transactions. (Bug #16310467)
InnoDB page-splitting algorithm could
For debug builds,
InnoDB status exporting was
subject to a race condition that could cause a server exit.
ALTER TABLE to set an
AUTO_INCREMENT column value to a
user-specified value, InnoDB would set the
AUTO_INCREMENT value to the user-specified
value even when the
AUTO_INCREMENT value is
greater than the user-specified value. This fix ensures that the
AUTO_INCREMENT value is set to the maximum of
the user-specified value and MAX(auto_increment_column)+1, which
is the expected behaviour.
InnoDB: Importing a tablespace with the configuration file present would not import the data file. This problem would occur when all pages are not flushed from the buffer pool after a table is altered using the copy and rename approach. This fix ensures that all pages are flushed from the buffer pool when a table is altered using the copy and rename approach. (Bug #16318052)
RENAME TABLE would result in a
hang due to a MySQL mutex acquisition deadlock.
InnoDB: Internal read operations could be misclassified as synchronous when they were actually asynchronous. When the I/O requests returned sooner than expected, threads could be scheduled inefficiently. This issue mainly affected read-ahead requests, and thus had relatively little impact on I/O performed by user queries. (Bug #16249505, Bug #68197)
lock_validate function, which is only
present in debug builds, acquired and released mutexes to avoid
hogging them. This behavior introduced a window wherein changes
to the hash table could occur while code traversed the same set
of data. This fix updates
to collect all records for which locks must be validated,
releases mutexes, and runs a loop to validate record locks.
ALTER TABLE functions would
perform a check to see if InnoDB is in read-only mode
srv_read_only_mode=true). If InnoDB was in
read-only mode, the check would return a successful status and
do nothing else. This fix replaces
srv_read_only_mode check conditions with
InnoDB now aborts execution on Windows by calling the
abort() function directly, as it does on
When the InnoDB buffer pool is almost filled with 4KB compressed
pages, inserting into 16KB compact tables would cause 8KB
pages_free to increase, which could
potentially slow or stall inserts.
An assertion failure would occur in
MEM_BLOCK_MAGIC_N due to a race condition that
row_merge_read_clustered_index() returned an
InnoDB: This fix removes an unnecessary debug assertion related to page_hash locks which only affects debug builds. The debug assertion is no longer valid and should have been removed when hash_lock array was introduced in MySQL 5.6. (Bug #16263167)
InnoDB: The InnoDB memcached plugin could encounter a serious error under a heavy load, such as produced by benchmark runs. (Bug #16182660, Bug #68096)
If the MySQL server halted at a precise moment when a purge
operation was being applied from the
change buffer, the
operation could be incorrectly performed again during the next
restart. A workaround was to set the configuration option
to turn off change buffering for purge operations.
(Bug #16183892, Bug #14636528)
InnoDB: When InnoDB locking code was revised, a call to register lock waits was inadvertently removed. This fix adds the call back to the InnoDB locking code. (Bug #16208201)
A direct call to the
would cause a debug assertion.
In the case of LOCK WAIT for an insert in a foreign key table,
InnoDB could report a false
dictionary-changed error and cause the insert to fail rather
than being retried.
InnoDB: In some cases, deadlock detection did not work, resulting in sessions hanging waiting for a lock-wait timeout. (Bug #16169638)
ALTER TABLE on an
InnoDB table could fail to delete the
statistics for the old primary key from the
This fix updates InnoDB code in
handler0alter.cc to use
TABLE::key_info instead of both
Arithmetic underflow during page compression for
CREATE TABLE on an
InnoDB table could cause a server exit.
For debug builds, online
TABLE operations for
could cause a server exit during table rebuilding.
In some cases, the
InnoDB purge coordinator
did not use all available purge threads, resulting in suboptimal
On systems that cannot handle unaligned memory access, depending
on the stack frame alignment, a
could occur during startup. This issue was observed on Solaris
ALTER TABLE for
InnoDB tables was not fully atomic.
was set to a value other than the default 1, the MySQL server
encountered a serious error during startup while loading the
InnoDB memcached plugin. In earlier releases, the server would
refuse to start (but not display an error) when this setting was
changed. This fix cleans up the error handling for unsupported
values of this configuration option.
(Bug #15907954, Bug #67670)
An error at the filesystem level, such as too many open files,
could cause an unhandled error during an
ALTER TABLE operation. The error
could be accompanied by Valgrind warnings, and by this assertion
Assertion `! is_set()' failed. mysqld got signal 6 ;
(Bug #14628410, Bug #16000909)
variable was incorrectly allowed to be configured at runtime. As
innodb_sync_array_size must be
configured when the MySQL instance is starting up, and cannot be
changed afterward. This fix changes
innodb_sync_array_size to a
non-dynamic variable, as intended.
The server could exit during an attempt by
InnoDB to reorganize or compress a compressed
secondary index page.
A DML operation performed while a
TABLE operation waits for pending I/O operations on
the tablespace to complete would result in a deadlock.
If the server was started with the
InnoDB otherwise failed to start,
query any of these Information Schema tables would cause a
Online DDL had a
restriction that prevented renaming a column and adding a
foreign key involving that column in a single
ALTER TABLE statement. Now, this
combination of operations is allowed in a single statement.
When printing out long semaphore wait diagnostics,
sync_array_cell_print() ran into a
segmentation violation (SEGV) caused by a race condition. This
fix addresses the race condition by allowing the cell to be
freed while it is being printed.
The value of the
variable was not updated consistently for all server releases
for the InnoDB Plugin in MySQL 5.1, and the integrated
InnoDB component in MySQL 5.5, 5.6, and
InnoDB and MySQL Server
development cycles are fully integrated and synchronized, now
the value returned by the
innodb_version variable is the
same as for the
(Bug #13463493, Bug #63435)
InnoDB: Killing a query caused an InnoDB assertion failure when the same table (cursor) instance was used again. This is the result of a regression error introduced by the fix for Bug#14704286. The fix introduced a check to handle kill signals for long running queries but the cursor was not restored to the proper state. (Bug #68051, Bug #16088883)
InnoDB: On startup, InnoDB reported a message on 64-bit Linux and 64-bit Windows systems stating that the CPU does not support crc32 instructions. On Windows, InnoDB does not use crc32 instructions even if supported by the CPU. This fix revises the wording of the message and implements a check for availability of crc32 instructions. (Bug #68035, Bug #16075806)
InnoDB: The length of internally generated foreign key names was not checked. If internally generated foreign key names were over the 64 character limit, this resulted in invalid DDL from SHOW CREATE TABLE. This fix checks the length of internally generated foreign key names and reports an error message if the limit is exceeded. (Bug #44541, Bug #11753153)
This fix removes left-over prototype code for
srv_parse_log_group_home_dirs, and related
(Bug #68133, Bug #16198764)
Attempting to replace the default
full-text search (FTS) stopword list by creating an
InnoDB table with the same structure as
would result in an error.
TABLE revealed that the new
table was created with
InnoDB FTS stopword table validity check only
supported latin1. This fix extends the validity check for all
supported character sets.
(Bug #68450, Bug #16373868)
INPLACE, which was disallowed in MySQL 5.6.10 for DDL
statements operating on partitioned tables, can once again be
used with such statements.
References: See also Bug #14760210.
A query on a table partitioned by range and using
TO_DAYS() as a partitioing
function always included the first partition of the table when
pruning. This happened regardless of the range employed in the
BETWEEN clause of such a query.
(Bug #15843818, Bug #49754)
TABLE ... DROP PARTITION against a view caused the
server to crash, rather than fail with an error as expected.
A query result was not sorted if both
ORDER BY were
used and the underlying table was partitioned.
Inserting any number of rows into an
ARCHIVE table that used more than
1000 partitions and then attempting to drop the table caused the
MySQL Server to fail.
(Bug #13819630, Bug #64580)
Replication: When using GTIDs and binary log auto-positioning, the master had to scan all binary logs whenever the slave reconnected (due to reasons such as I/O thread failure or a change of master) before it could send any events to slave. Now, the master starts from the oldest binary log that contains any GTID not found on the slave. (Bug #16340322, Bug #68386)
Replication: When the server version of the master was greater than or equal to 10, replication to a slave having a lower server version failed. (Bug #16237051, Bug #68187)
Replication: When replicating to a MySQL 5.6 master to an older slave, Error 1193 (ER_UNKNOWN_SYSTEM_VARIABLE) was logged with a message such as Unknown system variable 'SERVER_UUID' on master, maybe it is a *VERY OLD MASTER*. This message has been improved to include more information, similar to this one: Unknown system variable 'SERVER_UUID' on master. A probable cause is that the variable is not supported on the master (version: 5.5.31), even though it is on the slave (version: 5.6.11). (Bug #16216404, Bug #68164)
A zero-length name for a user variable (such as
@``) was incorrectly considered to be a sign
of data or network corruption when reading from the binary log.
(Bug #16200555, Bug #68135)
When MTS is on and transactions are being applied, the slave
coordinator would hang when encountering a checksum error on a
transaction event. This was due to a deadlock situation in which
the coordinator assumed a normal stop while a worker waited for
the coordinator to dispatch more events. For debug builds, the
problem appeared as an assertion failure, which was due to the
coordinator not setting
encountering an error.
mysqlbinlog can connect to a remote server
and read its binary logs. In MySQL 5.6 and later, this tool can
also wait for the server to generate and send additional events,
in practice behaving like a slave connecting to a master. In
cases where the server sent a heartbeat,
mysqlbinlog was unable to handle it properly.
As a consequence, mysqlbinlog failed at this
point, without reading any more events from the server. To fix
this problem, mysqlbinlog now ignores any
binary log events of type
that it receives.
STOP SLAVE could cause a deadlock
when issued concurrently with a statement such as
SHOW STATUS that retrieved the
values for one or more of the status variables
(Bug #16088188, Bug #67545)
References: See also Bug #16088114.
--replicate-* options (see
Replication Slave Options and Variables) could in some cases
lead to a memory leak on the slave.
(Bug #16056813, Bug #67983)
`) characters were not always
handled correctly in internally generated SQL statements, which
could sometimes lead to errors on the slave.
(Bug #16084594, Bug #68045)
References: This bug is a regression of Bug #14548159, Bug #66550.
The session-level value for
gtid_next was incorrectly reset
on the slave for all rollbacks, which meant that GTIDs could be
lost for multi-statement transactions, causing the slave to stop
with an ER_GTID_NEXT_TYPE_UNDEFINED_GROUP
error. Now this is done only when a complete transaction is
being rolled back, or when
autocommit is enabled.
In order to provision or to restore a server using GTIDs, it is
possible to set
a given GTID set listing the transactions that were imported.
This operation requires that the global
gtid_purged server system
variables are empty. (This is done in order to avoid the
possibility of overriding server-generated GTIDs.)
The error message GTID_PURGED can only be set when GTID_EXECUTED is empty that was raised when this requirement was not met could be confusing or misleading because it did not specify the scope of the affected variables. To prevent this from happening, error messages that refer to variables relating to GTIDs now specify the scope of any such variables when they do so. (Bug #16084426, Bug #68038)
In certain cases, the dump thread could send a heartbeat out of
synchronisation with format description events. One of the
effects of this issue what that, after provisioning a new server
from a backup data directory and setting
--gtid-mode=ON and enabling
CHANGE MASTER TO Syntax),
replication failed to start, with the error Read
invalid event from master.... The same problem could
also cause GTID-based replication to fail due to skipped events
following a unplanned shutdown of the master.
Replication: In some cases, when the slave could not recognize the server version of the master, this could cause the slave to fail. (Bug #16056365)
Table IDs used in replication were defined as type
ulong on the master and
uint on the slave. In addition, the maximum
value for table IDs in binary log events is 6 bytes
(281474976710655). This combination of factors led to the
Data could be lost on the slave when a table was assigned an
ID greater than
Table IDs greater than 281474976710655 were written to the binary log as 281474976710655.
This led to a stopped slave when the slave encountered two tables having the same table ID.
To fix these problems, IDs are now defined by both master and
slave as type
ulonglong but constrained to a
range of 0 to 281474976710655, restarting from 0 when it exceeds
(Bug #14801955, Bug #67352)
Replication: Internal objects used for relay log information were only partially deleted before freeing their memory. (Bug #14677824)
Replication: It was possible in certain cases—immediately after detecting an EOF in the dump thread read event loop, and before deciding whether to change to a new binary log file—for new events to be written to the binary log before this decision was made. If log rotation occurred at this time, any events that occurred following EOF detection were dropped, resulting in loss of data. Now in such cases, steps are taken to make sure that all events are processed before allowing the log rotation to take place. (Bug #13545447, Bug #67929)
References: See also Bug #16016886.
Replication: If the disk becomes full while writing to the binary log, the server hangs until space is freed up manually. It was possible after this was done for the MySQL server to fail, due to an internal status value being set when not needed. Now in such cases, rather than trying to set this status, a warning is written in the error log instead. (Bug #11753923, Bug #45449)
Microsoft Windows: In Shared Memory mode, the MySQL Server could crash when receiving requests from multiple threads. (Bug #13934876)
Failure to handle a full-text search wildcard properly could cause the server to exit. (Bug #16446108)
InnoDB now reports row and table locks to the
thread pool plugin. Deadlocks within a thread group could occur
SHOW ENGINE PERFORMANCE_SCHEMA STATUS could
report incorrect memory-allocation values when the correct
values exceeded 4GB.
Performance Schema statement tokenization overhead was reduced. (Bug #16382260)
A long database name in a
statement could cause the server to exit.
On Linux, a race condition involving
could cause the thread pool plugin to miss events. This was most
likely on systems with greater than 16 cores.
The server could exit if a prepared statement attempted to create a table using the name of an existing view while an SQL handler was opened. (Bug #16385711)
For debug builds, checking of password constraints could raise an assertion for statements that updated passwords. (Bug #16289303)
BUILD-CMAKE file in MySQL distributions
was updated with the correct URL for CMake
The optimizer's attempt to remove redundant subquery clauses
raised an assertion when executing a prepared statement with a
subquery in the
ON clause of a join in a
References: This bug is a regression of Bug #15875919.
values could cause an assertion to be raised.
Some aggregate queries attempted to allocate excessive memory. (Bug #16343992)
Incorrect results were returned if a query contained a subquery
IN clause which contained an
XOR operation in the
For debug builds, an assertion could be raised if a statement
failed with autocommit enabled just before an
XA START statement
Conversion of numeric values to
BIT could yield unexpected
HAVING clauses were rejected as
Fixed warnings when compiling with XCode 4.6. Fixed warnings
when compiling when the
isoctal macro was already defined in the
(Bug #16265300, Bug #60911, Bug #12407384)
Queries using range predicates that were evaluated using the LooseScan semi-join strategy could return duplicate rows. (Bug #16221623)
References: This bug is a regression of Bug #14728469.
For upgrade operations, RPM packages produced unnecessary errors
about being unable to access
In the range optimizer, an index merge failure could cause a server exit. (Bug #16241773)
A full-text query using Boolean mode could return zero results in some cases where the search term was a quoted phrase:
If the quoted phrase was preceded by a + sign. For example, this combination of a Boolean + operator and a phrase would return zero results:
where match(content) against('+"required term due to plus sign"' in boolean mode)
If the quoted phrase contained any stopwords. For example, the stopword "the" inside the phrase caused the query to return zero results:
where match(content) against('"stopword inside the phrase"' in boolean mode)
(Bug #16206253, Bug #68150)
For debug builds, the server could exit due to incorrect
calculation of applicable indexes for a join that involved
A bug in range optimization sometimes led to incorrect condition calculation for index merge union. This could lead to missing rows. (Bug #16164031, Bug #68194, Bug #16229746)
The Performance Schema could return incorrect values for the
PROCESSLIST_INFO column of the
Invocation of the range optimizer for a
select caused the server to exit.
mysql_config --libs displayed incorrect output. (Bug #16200717)
CREATE TABLE (...
statement for which
col_name TIMESTAMP DEFAULT
CURRENT_TIMESTAMP ...) ... SELECT
SELECT did not provide a value for the
TIMESTAMP column, that column was set to
'0000-00-00 00:00:00', not the current timestamp.
yaSSL did not perform proper padding checks, but instead examined only the last byte of plaintext and used it to determine how many bytes to remove. (Bug #16218104)
GROUP BY WITH ROLLUP in a prepared
statement could cause the server to exit.
If, in a
HAVING clause contained a function call which
itself contained an alias to a selected expression, the server
could sometimes exit.
system variable to an inappropriate value could cause the server
Directory name manipulation could result in stack overflow on Mac OS X and Windows. (Bug #16066243)
With statement-based binary logging, dropping a
could cause a segmentation fault.
For debug builds, if the server was started with binary logging
EVENTS from within a stored procedure raised an
The query parser leaked memory for some syntax errors. (Bug #16040022)
With the thread pool plugin enabled, large numbers of connections could lead to a Valgrind panic or failure of clients to be able to connect. (Bug #16088658, Bug #16196591)
The server executed
FORMAT=JSON for some malformed queries improperly.
Performance Schema instrumentation was missing for slave worker threads. (Bug #16083949)
test database contained a
dummy.bak file that prevented
DATABASE from working. This file is no longer
included. Also, a
db.opt file is now included
that contains these lines:
Setting a system variable to
cause the server to exit.
SET PASSWORD and
GRANT ... IDENTIFIED
BY have no effect on the password of a user who is
authenticated using an authentication plugin that accesses
passwords stored externally to the mysql.user table. But
attempts to change the password of such a user produced no
warning, leading to the impression that the password had been
changed when it was not. Now MySQL issues an
warning to indicate that the attempt was ignored.
For debug builds, creating an InnoDB table in strict SQL mode that violated the maximum key length limit caused the server to exit. (Bug #16035659)
PREPARE statement using certain
combinations of stored functions and user variables caused the
server to exit.
Joins of exactly 32 tables and containing a
HAVING clause returned an empty result.
mysys library string-formatting routine
could mishandle width specifiers.
could set connection character set system variables to values
ucs2 that are not permitted.
During shutdown, the server could attempt to lock an uninitialized mutex. (Bug #16016493)
permitted invalid plugin values, and did not always set the
old_passwords system variable to a value
appropriate for the named plugin.
Under some circumstances, mysql --secure-auth permitted passwords to be sent to the server using the old (pre-4.1) hashing format. (Bug #15977433)
When a partition is missing, code in
ha_innodb.cc would retry 10 times and sleep
for a microsecond each time while holding
LOCK_open. The retry logic for partitioned
tables was introduced as a fix for Bug#33349 but did not include
a test case to validate it. This fix removes the retry logic for
partitioned tables. If the problem reported in Bug#33349
reappears, a different solution will be explored.
With index condition pushdown enabled, queries for which the pushed-down condition contained no columns in the used index could be slow. (Bug #15896009)
Table creation operations added entries to the Performance
file_instances table, but
these were not always removed for table drop operations.
In special cases, the optimizer did not consider indexes that
were applicable to query processing, resulting in potentially
suboptimal execution and incorrect
(Bug #15849135, Bug #16094171)
A query with an
ORDER BY clause ordering by an outer
column of type
BLOB that is not in the select
list caused an assertion to fire.
References: See also Bug #14728142.
InnoDB table with a
FULLTEXT index could encounter a serious
error if the table name contained nonalphanumeric characters.
(Bug #14835178, Bug #16036699)
Enabling the query cache during high client contention could cause the server to exit. (Bug #14727815)
The MSI Installer installed MySQL in “per-user” mode, which could result in conflicts or failure to detect an existing installation if two users installed MySQL on the same machine. Now the MSI Installer uses “per-machine” installation mode. (Bug #14711808)
The server sometimes failed to respect
MAX_CONNECTIONS_PER_HOUR limits on user
The optimizer could return incorrect results after transforming
IN subquery with aggregate functions to an
When a client program loses the connection to the MySQL server
or if the server begins a shutdown after the client has executed
mysql_stmt_prepare(), the next
mysql_stmt_prepare() returns an
error (as expected) but subsequent
mysql_stmt_execute() calls crash
Previously, if multiple
were given, mysql_config_editor ignored all
but the last one. Now multiple
options result in an error.
SET PASSWORD for anonymous users
did not work correctly.
system variables indicate key files for the
sha256_password authentication plugin, but
the server failed to properly check whether the key files were
valid. Now in the event that either key file is invalid, the
server logs an error and exits.
cause the server to exit. This syntax is now prohibited because
SET context there is no column name and
the statement returns
COM_CHANGE_USER command in the
client/server protocol did not properly use the character set
number in the command packet, leading to incorrect character set
conversion of other values in the packet.
with a locale and a very large number could cause the server to
yaSSL rejected some valid server SSL certificates. (Bug #13777928)
Certain plugin-related conditions can make a user account unusable:
The account requires an authentication plugin that is not loaded.
The account requires the
authentication plugin but the server was started with
neither SSL nor RSA enabled as required by this plugin.
The server now checks those conditions by default and produces
warnings for unusable accounts. This checking slows down server
FLUSH PRIVILEGES, so it is
made optional by means of the new
validate_user_plugins system variable. This
variable is enabled by default, but if you do not require the
additional checking, you can disable it at startup to avoid the
(Bug #13010061, Bug #14506305)
Passing an unknown time zone specification to
CONVERT_TZ() resulted in a memory
glibc-2.2.5.patch files in the
Docs directory of MySQL distributions have
mysql_install_db did not escape
'_' in the host name for statements written
to the grant tables.
mysqld_safe used the nonportable
-e test construct.
(Bug #67976, Bug #16046140)
An out-of-memory condition could occur while handling an out-of-memory error, leading to recursion in error handling. (Bug #49514, Bug #11757464)
The optimizer used loose index scan for some queries for which this access method is inapplicable. (Bug #42785, Bug #11751794)
If a dump file contained a view with one character set and collation defined on a view with a different character set and collation, attempts to restore the dump file failed with an “illegal mix of collations” error. (Bug #65382, Bug #14117025)
REPLACE() function produced
incorrect results when a user variable was supplied as an
argument and the operation was performed on multiple rows.
(Bug #49271, Bug #11757250)
UNION type conversion could
incorrectly turn unsigned values into signed values.
(Bug #49003, Bug #11757005)
View access in low memory conditions could raise a debugging assertion. (Bug #39307, Bug #11749556)
Queries with many values in a
were slow due to inclusion of debugging code in non-debugging
(Bug #68046, Bug #16078212)
References: See also Bug #58731, Bug #11765737.
max_connections to a
value less than the current number of open connections caused
the server to exit.
(Bug #44100, Bug #11752803)
Some table I/O performed by the server when calling a storage engine were missing from the statistics collected by the Performance Schema. (Bug #68180, Bug #16222630)
For debug builds, some queries with
SELECT ... FROM
DUAL nested subqueries raised an assertion.
(Bug #60305, Bug #11827369)
Nonspatial indexes only support exact-match lookups for spatial
columns, but the optimizer incorrectly used
range access in some cases,
leading to incorrect results.
(Bug #67889, Bug #15993693)
If mysql is built with the bundled
libedit library, the library is built as
static code, to avoid linking to a different dynamic version at
runtime. Dynamic linking could result in use of a different,
incompatible version and a segmentation fault.
(Bug #68231, Bug #16296509)
command options now are exposed at runtime as the
system variables. Their values can be examined using
SHOW VARIABLES. The variables are
dynamic, so their values can be set at runtime. (The options
were actually replaced by the system
variables, but as system variables can be set at server startup,
no option functionality is lost.)
(Bug #59860, Bug #11766693)
For arguments with fractional seconds greater than six decimals,
SEC_TO_TIME() truncated, rather
than rounding as it should have.
(Bug #68061, Bug #16093024)
MySQL failed to build if configured with
(Bug #67018, Bug #16342793)
resulted in link errors due to selection of the incorrect
(Bug #68277, Bug #16284051)
ALTER TABLE inserted
col_name TIMESTAMP DEFAULT
CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
0000-00-00 00:00:00 rather than the current
timestamp if the alteration was done in place rather than by
making a table copy.
(Bug #68040, Bug #16076089)
If the server was started with
ALTER USER ... PASSWORD EXPIRE caused the
server to exit.
(Bug #68300, Bug #16295905)
CMake did not check whether the system
zlib had certain functions required for
MySQL, resulting in build errors. Now it checks and falls back
to the bundled
zlib if the functions are
(Bug #65856, Bug #14300733)
mysql_install_db did not work in Solaris 10 sparse root zones. (Bug #68117, Bug #16197860)
EXPLAIN DELETE and
listed all indexes, not just the applicable indexes.
(Bug #67830, Bug #15972078)
The Perl version of mysql_install_db mishandled some error messages. (Bug #68118, Bug #16197542)
ORDER BY and
LIMIT could lead to incorrect results for
(Bug #68458, Bug #16383173)
ORDER BY clause following an
IN subquery could cause duplicate rows to be
(Bug #68330, Bug #16308085)
A statement with an aggregated, nongrouped outer query and an
aggregated, nongrouped subquery in the
list could return incorrect results.
(Bug #68372, Bug #16325175)
NULL into a
TIMESTAMP NOT NULL column now produces an
error (as it already did for other
data types), instead of inserting the current timestamp.
(Bug #68472, Bug #16394472)