Known limitations of this release:
InnoDB may fail to open a tablespace that
has multiple data files due to newly introduced corruption
checking functionality. It is recommended that you do not
upgrade to this version if you have more than one file for
InnoDB tablespace. If you have
upgraded to an affected version and the server no longer
starts, you can upgrade to a later version when it becomes
available or downgrade to an earlier version.
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.
Functionality Added or Changed
mysql_upgrade now verifies that the server
version matches the version against which it was compiled, and
exits if there is a mismatch. In addiion, a
permits specifying whether to enable version checking (the
default), or disable checking if given as
When used for an existing MySQL account, the
GRANT statement could produce
unexpected results if it included an
WITH clause that named an authentication plug
differing from the plugin named in the corresponding
mysql.user table row.
IDENTIFIED WITH is intended only for
GRANT statements that create a
new user, it is now prohibited if the named account already
Important Change; Replication:
When the server was running with
NULL (that is, there was no currently
selected database), statements using fully qualified table names
format were not written to the binary log. This was because the
lack of a currently selected database in such cases was treated
as a match for any possible ignore option rather than for no
such option; this meant that these statements were always
Now, if there is no current database, a statement using fully qualified table names is always written to the binary log. (Bug #11829838, Bug #60188)
Joins involving partitioned
tables having one or more
columns were not always handled correctly. The
BLOB column or columns were not required to
be join columns, or otherwise to be named or referenced in the
statement containing the join, for this issue to occur.
In debug builds, an online
TABLE operation that performed a full table copy would
raise an assertion. The assertion was due to a race condition
that would occur during BLOB retrieval, when applying the table
modification log to any log block except for the very last one.
This fix modifies
row_log_table_apply_convert_mrec() to ensure
that an index B-tree lock is acquired to protect the access to
log->blobs and the BLOB page.
When the function
trx_rollback_or_clean_recovered() rolls back
or cleans up transactions during a crash recovery, it removes
the trx objects from the
trx_sys list without
freeing up the memory used by those objects. To prevent a memory
leak, this fix adds
function that removes the trx objects.
A memory leak would occur in
space_id is equal to zero.
A missing comma in
output would break MySQL Enterprise Monitor parsing.
After a clean shutdown,
InnoDB does not check
.ibd file headers at startup. As a result,
in a crash recovery scenario,
load a corrupted tablespace file. This fix implements
consistency and status checks to avoid loading corrupted files.
InnoDB: This fix addresses a race condition that would occur between the rollback of a recovered transaction and creation of a secondary index in a locked operation. The race condition would corrupt the secondary index. (Bug #16593427)
InnoDB: DML operations on compressed temporary tables would result in a Valgrind error in the buffer manager stack. (Bug #16593331)
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.
recv_writer thread would only start after
all redo log scans finished. In the case of multiple redo log
scans, accumulated redo records would be applied after each scan
and before processing the next scan. The absence of the
recv_writer thread to help with flushing
would slow recovery or result in a server startup timeout. This
fix ensures that the
starts before the first scan batch is processed.
InnoDB: Under certain circumstances, LRU flushing would take a long time possibly affecting all flushing activity and causing a shutdown timeout. (Bug #16500209)
test.demo_test table failed to work when
defined as a
utf8 charset table.
In cases where threads are forced to do single page flushing,
fsync() would be triggered for all data
files. This fix allows for synchronous single page flushing.
This fix removes most calls to
OS_THREAD_SLEEP from InnoDB.
(Bug #16472953, Bug #68588)
FOR EXPORT would sleep too often while
flushing pages from buffer pools.
InnoDB: Concurrently inserting into a full-text table would cause some inserts to fail. Duplicate values would be generated for full-text search document IDs when performing inserts into a hidden full-text search document ID column. (Bug #16469399)
page_zip_available function would count
some fields twice.
This fix replaces the
LSN_MAX where the code refers
to log sequence numbers, or with
trx->no is initialized to an undefined
value. This change does not alter the value of the constant.
InnoDB: This fix corrects the text for InnoDB error 6025, which stated, “InnoDB: read can't be opened in ./ib_logfile0 mode.”. The corrected message states, “InnoDB: ./ib_logfile0 can't be opened in read mode.” The variable and mode in the message construct were transposed. (Bug #16434398)
Creating a foreign key constraint using the
INPLACE algorithm requires
foreign_key_checks to be set to 0
SET foreign_key_checks = 0;). As a result,
an appropriate duplicate ID check would not be performed.
In debug builds, an insert failed with an invalid assertion:
sync_thread_levels_g(array, level - 1, TRUE).
Multiple concurrent calls to
dict_update_statistics() would result in
unnecessary server load.
On 64-bit Windows builds,
not accept an allocation of more than 32GB. This limitation was
due to a bug that truncated the internal value for the InnoDB
buffer pool size to 32 bits on 64-bit Windows builds.
(Bug #16391722, Bug #68470)
DROP DATABASE failed if the
database contained an InnoDB table that had a data file in an
external data directory. The external data file had an
“InnoDB Symbolic Link” file type
.isl) that was not recognized by MySQL.
This fix adds
.isl as a known InnoDB file
RENAME TABLE would result in a
hang due to a MySQL mutex acquisition deadlock.
Under testing, a
TABLE operation resulted in a timeout due to a missing
acknowledgment that the purge thread had stopped.
For compressed tables, a page reorganize operation would always
MLOG_ZIP_PAGE_REORGANIZE record to
the redo log, which is only correct if
the page reorganize operation should log the compressed page
InnoDB: When tables are linked by foreign key constraints, loading one table would open other linked tables recursively. When numerous tables are linked by foreign key constraints, this would sometimes lead to a thread stack overflow causing the server to exit. Tables linked by foreign key constraints are now loaded iteratively. Cascade operations, which were also performed in a recursive manner, are now performed iteratively using an explicit stack. (Bug #16244691, Bug #65384)
After disabling foreign key checks with
DROP INDEX, the
table was no longer accessible after restarting the server. This
fix allows the table with missing foreign key indexes to be
SET foreign_key_checks=0. When
the table is accessible, the user must recreate the missing
indexes to fulfill the foreign key constraints.
(Bug #16208542, Bug #68148)
When a transaction is in
COMMITTED isolation level, gap locks are still taken
in the secondary index when a row is inserted. This occurs when
the secondary index is scanned for duplicates. The function
calls the function
LOCK_ORDINARY irrespective of the transaction
isolation level. This fix modifies the
function to call
LOCK_REC_NOT_GAP, based on the transaction
(Bug #16133801, Bug #68021)
Starting mysqld with
failed to allocate memory and returned NULL. For non-debug
builds there was no check in place and a segmentation fault
occurred. This fix adds a log message stating that memory failed
to be allocated, and adds an assertion.
(Bug #16069598, Bug #68025)
UNIV_DEBUG is enabled in debug builds,
buf_validate() is often called which
sometimes results in false alarms in tests on semaphore wait
timeout. This fix increases counter values to reduce false
explain_filename function, which provides
information about a partition by parsing the file name, would
return an error when attempting to parse a file name with no
Stopping the server, removing a database table (d1.t1)
.frm file from the data directory,
restarting the server, and dropping the database (d1), would
cause an assertion.
InnoDB: While processing read-write workloads, InnoDB would scan more pages than are required for flushing, unnecessarily consuming CPU resource. (Bug #16037180)
FLUSH TABLE FOR
EXPORT thread would cause a hang during shutdown. The
fix ensures that
ON DUPLICATE KEY UPDATE insert failure, caused by a
duplicate key error, would result in duplicate auto-increment
(Bug #14483484, Bug #66301)
TABLES statement on a GTID-enabled master caused
replication to fail. It was found that this misbehavior was
introduced by the fix for Bug #16062608, which disallowed
statements that perform an implicit commit but whose changes are
not logged when
set to any value other than
changes made in that fix have been reverted, and such statements
are (again) allowed without regard to the value of this
(Bug #16715809, Bug #69045)
Point-in-time recovery could fail when trying to restore a
single database from a binary log in row-based format using
mysqlbinlog with the
A crash-on-commit error caused
InnoDB to lose the previous
transaction following execution of a
MASTER statement. This occurred because the prepare
phase caused a flush to disk, while the commit phase did not
perform a corresponding flush within
To fix this problem,
RESET MASTER now causes
storage engine logs to be flushed on commit.
(Bug #16666456, Bug #68932)
When processing an
Delete_rows_log_event from the binary log,
the before image is hashed and stored in a hash table. Following
this, the original table is scanned for the desired records;
subsequent processing hashes each record fetched from the
original table and performs a lookup for it in the hash table.
However, columns read from the image that had originally been
NULL could instead contain random or
“garbage” data, causing the lookup (and thus
replication) to fail with an error such as Could not
execute Update_rows event on table....
References: See also Bug #11766865. This bug was introduced by Bug #16566658.
When used with the options
mysqldump printed the port number within
quotation marks, as if it were a string value rather than an
Replication: Due to time resolution issues on some systems, the time to be taken by the dump thread for a reply from the slave could be calculated to be less than zero, leading to Semi-sync master wait for reply fail to get wait time errors. Since this condition does not have a negative impact on replication, errors caused by these conditions have been reduced to warnings. (Bug #16579028)
Trying to update a column, previously set to
NULL, of a table with no primary key caused
replication to fail with Can't find record in
This issue was originally fixed in MySQL 5.6.3 but was inadvertently reintroduced in MySQL 5.6.6. (Bug #16566658)
References: See also Bug #16621923. This bug is a regression of Bug #11766865.
Running the server with
--log-slave-updates together with
--replicate-ignore-table in some
cases caused updates to user variables not to be logged.
When using mysqlbinlog and the
mysql client to roll forward two or more
binary logs on a server having GTIDs enabled, the
gtid_next variable was not
properly reset when switching from the first to the second
binary log, causing processing to halt with an error at that
Replication: When one or more GTID log events but no previous GTIDs log events were found in the binary log, the resulting error was mishandled and led to a failure of the server. (This is an extremely rare condition that should never occur under normal circumstances, and likely indicates that the binary log file has somehow been corrupted.) Now in such cases, an appropriate error is issued, and is handled correctly. (Bug #16502579, Bug #68638)
Attempting to execute
after importing new
slave_relay_log_info tables failed with an
empty error message. Now an appropriate error and message are
issued in such cases.
(Bug #16475866, Bug #68605)
Restarting the server after the
slave_relay_log_info table had been emptied
caused mysqld to fail while trying to return
(Bug #16460978, Bug #68604)
Replication: Extra binary log rotations were performed due to concurrent attempts at rotation when the binary log became full, which were allowed to succeed. This could lead to the unnecessary creation of many small binary log files. (Bug #16443676, Bug #68575)
When the size of an execution event exceeded the maximum set for
row-based replication could hang with Waiting for
slave workers to free pending events.
(Bug #16439245, Bug #68462)
Following disconnection from the master, the slave could under
certain conditions report erroneously on reconnection that it
had received a packet that was larger than
causing replication to fail.
(Bug #16438800, Bug #68490)
Replication: An SQL thread error during MTS slave recovery caused the slave to fail. (Bug #16407467, Bug #68506)
When using the options
mysqlbinlog failed to reset the counter used
to store the current position within the file when the binary
log on the server was rotated.
(Bug #16316123, Bug #68347)
When using mysqldump to back up a database
created with MySQL 5.6.4 or an earlier version, setting
the backup to fail, because pre-5.6.5 versions of MySQL did not
support GTIDs, and it could not be determined if GTIDs were
enabled for the database. This fix makes sure
mysqldump does not attempt to output a
@@global.gtid_purged statement when backing up any
(Bug #16303363, Bug #68314)
Replication: Deadlocks could sometimes occur on group commits with a high number of concurrent updates, as well as when one client held a lock from a commit while another client imposed a lock while rotating the binary log. (Bug #16271657, Bug #16491597, Bug #68251, Bug #68569)
When semisynchronous replication was enabled, the automatic
dropping on the master of an event created using
COMPLETION NOT PRESERVE caused the master to fail.
(Bug #15948818, Bug #67276)
SET column to
NULL inside a stored procedure caused
replication to fail.
(Bug #14593883, Bug #66637)
The binary log contents got corrupted sometimes, because the
thought it had reached the end-of-cache when the function
my_b_fill() reported a '0,' while that could
also mean an error had occurred. This fix makes sure that
my_b_fill() returns a '0,' an error
check is performed on
(Bug #14324766, Bug #60173)
PURGE BINARY LOGS by design does
not remove binary log files that are in use or active, but did
not provide any notice when this occurred. Now, when log files
are not removed under such conditions, a warning is issued; this
warning includes information about the file or files were not
removed when the statement was issued.
(Bug #13727933, Bug #63138)
When replicating to a
table using the binary logging format, updates and deletes
cannot be applied and so are skipped. Now a warning is generated
for this whenever it occurs.
Removing a server RPM package did not shut down the existing server if it was running. (Bug #16798868)
Overhead for setting
in the Performance Schema
table has been reduced.
The Windows authentication plugin failed to free a context buffer for each connection. (Bug #16591288)
DBUG_PRINT() macro unnecessarily
evaluated arguments when debugging was not enabled.
Geometry methods that worked with WKB data performed insufficient input data validation, which could cause Valgrind errors or a server exit. (Bug #16510712, Bug #12772601)
The server could attempt a
for a zero-size sort length, causing it to exit.
Opening a cursor on a
within a stored procedure could cause a segmentation fault.
References: This bug is a regression of Bug #14740889.
my_load_defaults() was modified to
accommodate some problems under compilation with
gcc 4.7.2 that could cause a client crash
during option processing.
SET PASSWORD treated
referring to the same
mysql.user table row.
When index condition pushdown was used on a descending range scan and the first range interval did not contain any qualifying records, the result of the range scan could be empty even if other range intervals contained qualifying records. (Bug #16483273)
The WKB reader for spatial operations could fail and cause a server exit. (Bug #16451878)
Optimizer heuristics inappropriately preferred range access over
ref access in cases when the
ref access referred to a column of a table
earlier in the join seqence.
Performance Schema parameter autosizing at startup did not take into account later autosizing changes to other startup parameters on which the Performance Schema parameters depended. (Bug #16430532)
INFORMATION_SCHEMA queries that used
ORDER BY did not use a
filesort optimization as they did in MySQL
Manually-created accounts (using
INSERT) with a malformed password
effectively had no password.
For debug builds,
DBUG_EXPLAIN resulted in a
buffer overflow when the
system variable value was more than 255 characters.
Several scripts in the
that were supposed to be executable did not have the executable
access bit set.
For debug builds, with an XA transaction in IDLE or PREPARED status, execution of a query with the query cache enabled could cause a server exit. (Bug #16388996)
Installing Debian packages on Ubuntu 12.10 succeeded using dpkg, but not with Software Center 18.104.22.168. (Bug #16387513)
Within an XA transaction in ACTIVE state, statements causing an implicit commit could result in metadata locks being released too early. (Bug #16362832)
For debug builds,
BY) within an
ORDER BY clause could
cause a server exit.
containing subquery having an outer reference caused the server
validate_password plugin did not always
enforce appropriate constraints against assigning empty
Re-execution of a stored procedure could cause a server exit in
For debug builds, the server could exit for queries involving a nested subquery, a subquery transformed into a semi-join and using a view. (Bug #16317076)
could not be set at server startup.
secure_auth enabled, a
user with a password that used the pre-4.1 (old) hashing could
not update it to use the 4.1 (new) hashing.
The range optimizer could set up incorrect ranges for queries
mysql_secure_installation could not connect
to the server if the account used had an expired password. It
invoked mysql noninteractively, resulting in
that program failing to connect. Now mysql
that indicates to the server that it can handle sandbox mode for
expired-password accounts even if invoked noninteractively, and
mysql with this option.
If loose index scan was used on a query that used
MIN(), a segmentation fault could
An outer join between a regular table and a derived table that is implicitly groups could cause a server exit. (Bug #16177639)
If multiple statements were sent in a single request, the audit log plugin logged only the last one. Now it logs each statement separately. (Bug #16169063)
For debug builds, an assertion was incorrectly raised for
queries executed using
eq_ref access and
A prepared statement that used
GROUP_CONCAT() and an
ORDER BY clause that named multiple columns
could cause the server to exit.
ORDER BY MATCH ... AGAINST could cause a
FEDERATED table without
specifying a connection string caused a server exit.
Client programs from MySQL 5.6.4 and up could confuse older servers during the connection process by using newer protocol features not understood by older servers. (Bug #15965409)
The mysql.server script exited with an error
status command was executed with
multiple servers running.
The mysql client allocated but did not free a string after reading each line in interactive mode, resulting in a memory leak. (Bug #14685362)
Killing a connection while it was in the process of disconnecting could lead to an assertion being raised, Valgrind warnings, and general unstability. (Bug #14560522)
INSERT ... ON DUPLICATE
KEY UPDATE on a view could cause a server exit.
Grouping by an outer
in a subquery caused a server exit.
(Bug #13966809, Bug #14700180)
The server could exit due to improper handling of the error from an invalid comparison. (Bug #13009341)
The CMake check for
time_t failed on all platforms.
mysqladmin debug causes the server to write
debug information to the error log. On systems that supported
mallinfo(), the memory-status part of this
output was incorrect in 64-bit environments when
mysqld consumed more than 4GB memory.
Now the server uses
malloc_info() to obtain
not report the memory that the
malloc() implementation internally allocates
mmap(). However, it does provide the
memory usage information in all the memory arenas.
This bug fix also involves a change of output format. The server now writes memory information in XML format rather than as plain text. Example:
Memory status: <malloc version="1"> <heap nr="0"> <sizes> <size from="33" to="33" total="1056" count="32"/> <size from="65" to="65" total="65" count="1"/> <size from="113" to="113" total="226" count="2"/> <size from="129" to="129" total="2451" count="19"/> <size from="145" to="145" total="290" count="2"/> <size from="161" to="161" total="1288" count="8"/> <size from="209" to="209" total="418" count="2"/> </sizes> <total type="fast" count="0" size="0"/> <total type="rest" count="66" size="5794"/> <system type="current" size="10833920"/> <system type="max" size="10833920"/> <aspace type="total" size="10833920"/> <aspace type="mprotect" size="10833920"/> </heap> <total type="fast" count="0" size="0"/> <total type="rest" count="66" size="5794"/> <system type="current" size="10833920"/> <system type="max" size="10833920"/> <aspace type="total" size="10833920"/> <aspace type="mprotect" size="10833920"/> </malloc>
FOUND_ROWS() could return an
incorrect value if the preceding query used
(Bug #69119, Bug #16760474)
References: This bug is a regression of Bug #68458.
The optimizer could choose a poor execution plan for queries
ORDER BY ... LIMIT.
(Bug #69013, Bug #16697792)
When specified in an option file, the
plugin-dir client option was ignored.
(Bug #68800, Bug #16680313)
When only counting events but not timing them, Performance
Schema would report
MIN_TIMER_WAIT values as
a large number instead of 0.
(Bug #68768, Bug #16552425)
Using range access with an index prefix could produce incorrect results. (Bug #68750, Bug #16540042)
For debug builds, metadata locking for
CREATE TABLE ...
SELECT could raise an assertion.
(Bug #68695, Bug #16503173)
A new CMake option,
WITH_EDITLINE, is provided to
indicate whether to use the bundled or system
The permitted values are
If Loose Index Scan was used to evaluate a query that compared
an integer column to an integer specified as a quoted string
), the query could return incorrect results.
(Bug #68473, Bug #16394084)
In a MySQL server newer than MySQL 5.5 using a nonupgraded
mysql.user table (for which
mysql_upgrade had not been run), statements
to set passwords caused a server exit due to a faulty check for
(Bug #68385, Bug #16339767)
Indexes on derived tables that were used during the first invocation of a stored procedure were not used in subsequent invocations. (Bug #68350, Bug #16346367)
If a function such as
AES_DECRYPT() that requires SSL
support failed, the error could affect later calls to functions
that require SSL support.
(Bug #68340, Bug #16315767)
The mysql client incorrectly used
latin1 for certain comparisons even if
started with a multibyte default character set, resulting in a
(Bug #68107, Bug #16182919)
InnoDB does not support full-text parser
plugins, but failed to report an error if they were specified.
error is returned.
(Bug #62004, Bug #12843070)
url columns in the
mysql datatbase help tables were too short to
hold some of the URLs in the help content. These columns are now
created as type
accommodate longer URLs.
(Bug #61520, Bug #12671635)
Two problems adding or subtracting keyword from the current
debug system variable setting
debug value of
'd' means “all debug macros
enabled”. The following sequence left the value in an
SET debug = 'd';SELECT @@debug;+---------+ | @@debug | +---------+ | d | +---------+ mysql>
SET debug = '+d,M1';SELECT @@debug;+---------+ | @@debug | +---------+ | d,M1 | +---------+
statement enables all debug macros. The second
should add the
M1 macro to the current
set, which should result in no change because the current
set is already “all macros”. Instead, the
reset the current set to only the
macro, effectively disabling all others. The server now
debug value of
'' means “no debug macros
enabled”. The following sequence left the value in an
SET debug = 'd,M1';SELECT @@debug;+---------+ | @@debug | +---------+ | d,M1 | +---------+ mysql>
SET debug = '-d,M1';SELECT @@debug;+---------+ | @@debug | +---------+ | d | +---------+
debug to the
M1* macro. The second
should subtract the
M1 macro from the
current set, leaving no debug macros enabled. Instead, the
reset the current set to
'd' (all macros
enabled). The server now correctly sets
(Bug #58630, Bug #11765644)
It is now possible to suppress installation of the
mysql-test directory after compiling MySQL
from source by invoking CMake with the
explicitly set to empty:
cmake . -DINSTALL_MYSQLTESTDIR=
Previously, attempts to do this resulted in an error. (Bug #58615, Bug #11765629)
On 64-bit Mac OS X systems, CMake used
x86 rather than
when determining the machine type.
(Bug #58462, Bug #11765489)
IF() function evaluations could
produce different results when executed in a prepared versus
(Bug #45370, Bug #11753852)