Known limitations of this release:
On Microsoft Windows, MySQL Installer does not upgrade MySQL Enterprise Backup (MEB) 3.8.1 to 3.8.2 (latest version). A workaround is to uninstall MEB 3.8.1 and then install MEB 3.8.2 (latest version) with MySQL Installer.
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
Previously, the Performance Schema statement instrumentation did
not include statements executed on a slave replication server.
To address this, a new abstract instrument,
statement/rpl/relay_log, has been added to
setup_instruments table. This
instrument is used during the early stages of replicated
statement classification before the exact statement type is
In addition, the
statement instrument was renamed to
Applications that refer to the old instrument names must be updated with the new names. For more information about the use of abstract instruments in statement classification, see Performance Schema Statement Event Tables. (Bug #16750433, Bug #17271055)
Important Change; Replication:
By default, when promoting integers from a smaller type on the
master to a larger type on the slave (for example, from a
SMALLINT column on the master to
BIGINT column on the slave),
the promoted values are treated as though they are signed. Now
in such cases it is possible to modify or override this behavior
using one or both of
ALL_UNSIGNED in the set of values specified
server system variable. For more information, see
Row-based replication: attribute promotion and demotion, as
well as the description of the variable.
Previously, program options could be specified in full or as any
unambiguous prefix. For example, the
--compress option could be
given to mysqldump as
--compr, but not as
because the latter is ambiguous. Option prefixes now are
deprecated. They can cause problems when new options are
implemented for programs. A prefix that is currently unambiguous
might become ambiguous in the future. If an unambiguous prefix
is given, a warning now occurs to provide feedback. For example:
Warning: Using unique option prefix compr instead of compress is deprecated and will be removed in a future release. Please use the full name instead.
Option prefixes are no longer supported in MySQL 5.7; only full options are accepted. (Bug #16996656)
The C API
.so files now have version 18.1.0 (up from
version 18.0.0 used in MySQL 5.5). 18.1.0 can be used as a
replacement for 18.0.0.
(Bug #16809055, Bug #59106, Bug #12407476)
In batch mode, mysql formatted result status messages such as “"Query OK, 1 row affected"” but did not print them. Now these messages are not formatted. (Bug #69486, Bug #16971432)
Performance; Important Change; InnoDB:
InnoDB failed to open a tablespace that has
multiple data files. This removes the known limitation that was
in MySQL Server 5.6.12.
(Bug #17033706, Bug #69623)
A code regression introduced in MySQL 5.6 negatively impacted
DROP TABLE and
ALTER TABLE performance. This
could cause a performance drop between MySQL Server 5.5.x and
(Bug #16864741, Bug #69316)
is set to a non-zero value, there was a possibility that all
would be released after each row was read, resulting in a
concurrency check after each read. This could impact performance
of all queries. One symptom could be higher system CPU usage. We
strongly recommend that you upgrade to MySQL Server 5.6.13 if
you use this setting. This could cause a performance drop
between MySQL Server 5.5.x and 5.6.x.
(Bug #68869, Bug #16622478)
SET sql_mode = ''; CREATE TABLE t (d DATE DEFAULT 0); SET sql_mode = 'NO_ZERO_DATE,STRICT_ALL_TABLES'; INSERT INTO t (d) VALUES(DEFAULT);
In this case, 0 should be accepted for the
CREATE TABLE but rejected for the
INSERT. However, previously the
server did not evaluate
DEFAULT values used
for inserts or updates against the current
sql_mode. In the example, the
INSERT succeeds and inserts
'0000-00-00' into the
The server now applies the proper
sql_mode checks to generate a
warning or error at insert or update time.
A resulting incompatibility for replication if you use
that if a slave is upgraded, a nonupgraded master will execute
the preceding example without error, whereas the
INSERT will fail on the slave and
replication will stop.
To deal with this, stop all new statements on the master and
wait until the slaves catch up. Then upgrade the slaves followed
by the master. Alternatively, if you cannot stop new statements,
temporarily change to row-based logging on the master
binlog_format=ROW) and wait
until all slaves have processed all binary logs produced up to
the point of this change. Then upgrade the slaves followed by
the master and change the master back to statement-based
(Bug #68041, Bug #16078943)
InnoDB: A full-text search using the IN BOOLEAN MODE modifier would result in an assertion failure. (Bug #16927092)
References: This bug is a regression of Bug #16516193.
CHECK TABLE found a
secondary index that contained the wrong number of entries, it
would report an error but not mark the index as corrupt.
CHECK TABLE now marks the index
as corrupt when this error is encountered, but only the index is
marked as corrupt, not the table. As a result, only the index
becomes unusable until it is dropped and rebuilt. The table is
InnoDB would attempt to gather statistics on
partially created indexes.
InnoDB: The server would crash during a memcached set operation. The failure was due to a padded length value for a utf8 char column. During a memcached update operation, a field from an old tuple would be copied with a data length that was less than the padded utf8 char column value. This fix ensures that old tuples are not copied. Instead, a new tuple is created each time. (Bug #16875543)
INFORMATION_SCHEMA tables for the
InnoDB buffer pool could show an invalid page type for
read-fixed blocks. This fix will show the unknown page type for
blocks that are I/O-fixed for reading.
Removed invalid compilation warning messages that appeared when
InnoDB memcached plugin.
InnoDB: A memory leak would occur when inserting or replacing a row in a full-text search index on a table with more than 96 columns. (Bug #16809167)
During an insert buffer merge, InnoDB would invoke
lock_rec_restore_from_page_infimum() on a
potentially invalid record pointer.
innodb_rwlock_x_spin_waits item in the
table would show the same value as the
In debug builds, an assertion could occur in
OPT_CHECK_ORDER_BY when using binary directly
in a search string, as binary may include
NULL bytes and other non-meaningful
characters. This fix will remove non-meaningful characters
before the search is run.
Valgrind testing returned memory leak errors which resulted from
a regression introduced by the fix for Bug #11753153. The
function would call
failed to call
page_zip_validate() consistency check
failed after compressing a page, in
page_zip_compress(). This problem was caused
page_zip_decompress(), which failed to set
heap_no correctly when a record contained no
user data bytes. A record with no user data bytes occurs when,
for example, a primary key is an empty string and all secondary
index fields are NULL or an empty string.
InnoDB: Some characters in the identifier for a foreign key constraint are modified during table exports. (Bug #16722314, Bug #69062)
InnoDB memcached connections would
result in a memory leak.
(Bug #16707516, Bug #68530)
InnoDB full-text search (FTS)
results could consume an excessive amount of memory. This bug
fix reduces memory consumption for FTS results and introduces a
new configuration parameter,
which places a default size limit of 2000000000 bytes on the
InnoDB FTS query result cache.
has an unlimited maximum value and can be set dynamically.
During a transaction commit,
prepare_commit_mutex is acquired to preserve
the commit order. If the commit operation failed, the
transaction would be rolled back but the mutex would not be
released. Subsequent insert operations would not be able to
acquire the same mutex. This fix frees
When the InnoDB shutdown mode
innodb_fast_shutdown) is set
to 2 and the master thread enters the flush loop, the thread
would not be able to exit under some circumstances. This could
lead to a shutdown hang.
Restarting InnoDB in read-only mode and running a workload would
occasionally return a
While printing a UTF-8 table name,
would truncate the table name, resulting in an incomplete buffer
and subsequent Valgrind error. This bug fix also addresses an
incorrect debugging error message.
Attempting to create a table while in
innodb_read_only mode would
result in the following error:
ERROR 1015 (HY000):
Can't lock file (errno: 165 - Table is read only).
Creating numerous tables, each with a full-text search index,
could result in excessive memory consumption. This bug fix adds
a new configuration parameter,
which defines a global memory limit for full-text search
indexes. If the global limit is reached by an index operation, a
force sync is triggered.
(Bug #14834698, Bug #16817453)
In the error log, a full-text search index would be reported
missing from the data dictionary during a
TRUNCATE TABLE operation. After
restarting mysqld, the following
InnoDB error would be reported:
“InnoDB: Error: trying to load index idx13 for
table test/g1 but the index tree has been
References: See also Bug #17402002.
row_check_index_for_mysql method, which
checks for NULL fields during an index scan or
CHECK TABLE operation, would
iterate unnecessarily. Thanks to Po-Chun Chang for the patch to
correct this issue.
(Bug #69377, Bug #16896647)
When running an
InnoDB full-text search in
boolean mode, prefixing an asterisk (
*) to a
search string (
'*string') would result in an
error whereas for
MyISAM, a prefixed asterisk
would be ignored. To ensure compatibility between
InnoDB now handles a prefixed asterisk in the
same way as
(Bug #68948, Bug #16660607)
Successive deletes in descending key order would lead to
InnoDB index pages. When an
InnoDB index page is under-filled, it is
merged with the left or right sibling node. The check performed
to determine if a sibling node is available for merging was not
(Bug #68501, Bug #16417635)
ALTER TABLE to change
the character set of foreign key columns for a database with
multiple tables with foreign key constraints would leave the
database in an inconsistent state. Subsequent
TABLE operations (using the
fail due to the detected inconsistency. Reversion of the
ALTER TABLE operation
would also fail, resulting in the loss of the table being
altered. When running the same
operation with a
RENAME clause, the
inconsistency would not be detected but if the
TABLE operation failed for some other reason,
reversion of the partially executed
TABLE failed with the same result.
The bug fix temporarily disables
foreign_key_checks while the previous table
definition is restored.
(Bug #65701, Bug #14227431)
InnoDB: Creating a table with a comment or default textual value containing an apostrophe that is escaped with a backslash would sometimes cause the InnoDB storage engine to omit foreign key definitions. (Bug #61656, Bug #12762377)
commit_threads_m, which was initialized but
never used, has been removed from the code base.
(Bug #60225, Bug #11829813)
When upgrading to MySQL 5.5.31 or higher, a message is written
into the output of mysql_upgrade when
encountering a partitioned table for which the
ALGORITHM option is required to maintain
binary compatibility with the original; the message includes the
ALTER TABLE statement required to
make the change. For such a table having a sufficiently large
number of partitions, the message was truncated with an error
before the complete
ALTER TABLE statement
could be written.
When a range specified in the
of a query against a table partitioned by
RANGE entirely within that of one of the
partitions, the next partition was also checked for rows
although it should have been pruned away.
Suppose we have a range-partitioned table
created using the following SQL statement:
CREATE TABLE t ( id INT AUTO_INCREMENT, dt DATETIME, PRIMARY KEY (dt,id), UNIQUE KEY (id,dt) ) PARTITION BY RANGE COLUMNS(dt) ( PARTITION p0 VALUES LESS THAN ('2013-01-01'), PARTITION p1 VALUES LESS THAN ('2013-01-15'), PARTITION p2 VALUES LESS THAN ('2013-02-01'), PARTITION p3 VALUES LESS THAN ('2013-02-15'), PARTITION pmax VALUES LESS THAN (MAXVALUE) );
An example of a query that exhibited this issue when run against
t is shown here:
SELECT COUNT(*) FROM t WHERE dt >= '2013-02-01' AND dt < '2013-02-15';
In this case, partition
pmax was checked,
even though the range given in the
clause lay entirely within partition
When dropping a partitioned table, the table's
.par file was deleted first, before the
table definition or data. This meant that, if the server failed
during the drop operation, the table could be left in an
inconsistent state in which it could neither be accessed nor
The fix for this problem makes the following changes:
Now, when dropping a partitioned table, the table's
.par file is not removed until all
table data has been deleted.
DROP TABLE of
a partitioned table, in the event that its
.par file is determined to be missing,
.frm file is now
immediately deleted, in effect forcing the drop to complete.
(Bug #13548704, Bug #63884)
Replication: The condition leading to the issue fixed in Bug #16579083 continued to raise an error even though the condition itself no longer cause the issue to occur. (Bug #16931177, Bug #69369)
References: See also Bug #16271657, Bug #16491597, Bug #68251, Bug #68569.
was set to an extremely large value, semisynchronous replication
became very slow, especially when many sessions were working in
parallel. It was discovered that the code to calculate this
timeout was inside the wait loop itself, with the result that an
increase in the value of
rpl_semi_sync_master_timeout caused repeated
iterations. This fix improves the method used to calculate
wakeup times, and moves it outside of the wait loop, so that it
is executed one time only.
(Bug #16878043, Bug #69341)
It was possible to cause a deadlock after issuing
FLUSH TABLES WITH READ
LOCK by issuing
SLAVE in a new connection to the slave, then issuing
SHOW SLAVE STATUS using the
The fix for this includes the addition of the
variable, to control the time in seconds to wait for slave to
stop after issuing
STOP SLAVE before
returning a warning.
Some expressions employing variables were not handled correctly
In some circumstances, the message in the
Last_Error column from the output of
SHOW SLAVE STATUS referred to
GTID_NEXT_LIST although this variable is not
currently implemented (the name is reserved for possible future
use). Now in such cases the error message no longer refers to
(Bug #16742886, Bug #69096)
References: See also Bug #16715809, Bug #69045.
Linker errors occurred if the header file
log_event.h was included in an application
containing multiple source files, because the file
rpl_tblmap.cc was included in
log_event.h. This fix moves the inclusion of
rpl_tblmap.cc into the source files that use
The error displayed by
STATUS when a worker thread fails to apply an event
contained no event coordinate information. The GTID for the
event's group was also not shown. Now in such cases, the
text shown for
Last_SQL_Error is prefixed
with the (physical) master binary log coordinates, as well as
the value of
this has been set.
The warning issued when specifying
CHANGE MASTER TO was unclear for
a number of reasons, and has been changed to read,
Storing MySQL user name or password information in
the master info repository is not secure and is therefore not
recommended. Please consider using the USER and PASSWORD
connection options for START SLAVE; see 'START SLAVE Syntax' in
the MySQL Manual for more information.
(Bug #16460123, Bug #16461303, Bug #68602, Bug #68599)
After a transaction was skipped due to its GTID already having
been logged, all remaining executed transactions were
incorrectly skipped until
gtid_next was pointed to a
To avoid this incorrect behavior, all transactions—even
those that have been skipped—are marked as undefined when
they are commited or rolled back, so that an error is thrown
whenever a second transaction is executed following the same
After the client thread on a slave performed a
FLUSH TABLES WITH READ
LOCK and was followed by some updates on the master,
the slave hung when executing
(Bug #68460, Bug #16387720)
Reads from message buffers for closed connections could occur. (Bug #17003702)
The server could exit while using a cursor to fetch rows from a
perform an out-of-bounds read.
The range optimizer incorrectly assumed that any geometry function on a spatial index returned rows in ROWID order, which could result in incorrect query results. (Bug #16960800)
keycache_* variables (see
Multiple Key Caches) during server startup
could write to incorrect memory.
For debug builds, improper use of
dbug.c caused different code areas
to have different ideas about size and contents of a mutex. This
could result in out-of-bounds memory writes.
The Performance Schema could spawn a thread using incorrect instrumentation information. (Bug #16939689)
The server did excessive locking on the
active_mi->rli->data_lock mutexes for any
SHOW STATUS LIKE 'pattern' statement, even
when the pattern did not match status variables that use those
Slave_running). Now attempts
to show those variables do not lock those mutexes. This might
result is slightly stale data, but better performance.
Full-text phrase search in
could read incorrect memory.
It was not possible to keep several major versions of MySQL in the same yum repository. (Bug #16878042)
INSERT ... ON DUPLICATE KEY UPDATE could
cause a server exit if a column with no default value was set to
References: This bug is a regression of Bug #14789787.
In a prepared statement or stored routine, if the
HAVING clause of a subquery referenced some
column of the GROUP BY of the parent query, the server could
Compiling failed with
-DMY_ATOMIC_MODE_RWLOCKS=1 or on platforms on
which MySQL did not support lockless atomic operations (such as
The code base was modified to account for new warning checks introduced by gcc 4.8. (Bug #16729109)
system variable did not show the maximum number of open files
the mysqld process could have, but instead
the number that was requested after adjusting the
The server could make the wrong decision about whether an account password was expired. (Bug #16604641)
Some rows for a session could be missing sporadically from the
session_connect_attrs table while
the session was executing a workload.
Upgrading from community SLES RPM packages to commercial packages for the same MySQL version failed with conflict errors. (Bug #16545296)
If the optimizer was using a loose index scan, the server could exit while attempting to create a temporary table. (Bug #16436567)
Incorrect results or a server exit could be caused by a reference to an aggregated expression inside a nested subquery, where the aggregated expression was evaluated in a query block more than two levels outer to the reference. (Bug #16436383)
not support boolean full-text searches on nonindexed columns,
but this restriction was not enforced, resulting in queries that
returned incorrect results.
A full-text search syntax error failed to print to standard output. (Bug #16429688, Bug #16765397)
A server exit could occur for queries of the form
SELECT (SELECT 1 FROM t1) IN (SELECT a FROM
t1) when attempting to evaluate the constant left-hand
argument to the
IN subquery predicate.
An assertion could be raised when creating a index on a prefix
GEOMETRY column in an
(Bug #16368875, Bug #18776592, Bug #17665767)
In debug builds, failure in the range optimizer for an
ER_LOCK_WAIT_TIMEOUT error could
go undetected and cause an assertion to be raised when a
response was sent to the client. In release builds, this problem
manifested as clients receiving an
OK for a
statement that had failed.
(Bug #16366994, Bug #16247110)
Transforming some subqueries that select temporal or
BIGINT types or to a semijoin
caused a server exit on the second execution of prepared
statements or stored programs.
The server could exit in
due to an improper
No warning was generated if a duplicate index existed after dropping a column associated with a multiple-column index. (Bug #16315351)
SELECT DISTINCT with
ROLLUP could result in a
'NULL' for key '<auto_key>' error.
The usual failed-login attempt accounting was not applied to
(Bug #16241992, Bug #17357535)
A user variable referenced during execution of a prepared statement is set to memory that is freed at the end of execution. A second execution of the statement could result in Valgrind warnings when accessing this memory. (Bug #16119355)
Misoptimization of left expressions in prepared statements could cause a server exit. (Bug #16095534)
The optimizer trace could print ranges for key parts that were not usable for range access. (Bug #14615536)
Passwords in statements were not obfuscated before being written to the audit log. (Bug #14536456)
When running a query on
index_name values, query results would
include index pages without
commands in the client-server protocol did not have length
checks for incoming network packets, which could result in
various problems for malformed input.
With the thread pool plugin in use, normal connection
termination caused the
variable to be incremented.
On Windows, command-line options of the form
On all platforms, for Performance Schema options of the form
invalid instrument names now are rejected.
MySQL Installer, if run in custom install or change mode, offered installation options that had no effect. (Bug #12928601)
Incorrect results could be returned from queries that used
aggregate function such as
these referred to different columns of the same composite key.
RPM packages did not provide lowercase tags for their contents.
For example, a server RPM indicated that it provided
MySQL-server, but not
(Bug #69830, Bug #17211588)
When selecting a union of an empty result set (created with
WHERE 1=0 or
with a derived table, incorrect filtering was applied to the
(Bug #69471, Bug #16961803)
References: This bug is a regression of Bug #15848521.
For queries with
ORDER BY ... LIMIT, the
optimizer could choose a nonordering index for table access.
(Bug #69410, Bug #16916596)
When an internal buffer was too small for the workload, the Performance Schema could spend a lot of time in an internal spin loop attempting to allocate a memory buffer, and fail. (Bug #69382, Bug #16945618)
In the absence of
SQL_CALC_FOUND_ROWS in the
should return the number of rows in the result set, but this did
not always happen if the query contained
(Bug #69271, Bug #16827872)
Full-text search on
InnoDB tables failed on
searches for words containing apostrophes.
(Bug #69216, Bug #16801781)
UPDATE containing a
subquery caused a deadlock inside
InnoDB, the deadlock was not
properly handled by the SQL layer. The SQL layer then tried to
unlock the row after
InnoDB rolled back the
transaction, raising an assertion inside
(Bug #69127, Bug #16757869)
LEFT JOIN queries with
BY could return incorrect results.
(Bug #68897, Bug #16620047)
References: This bug is a regression of Bug #11760517.
Comparison of a
and a string did not work correctly for the
(Bug #68795, Bug #16567381)
Full-text search on
InnoDB tables failed on
searches for literal phrases combined with
(Bug #68720, Bug #16516193)
Optimizations that used extended secondary keys (see
Use of Index Extensions) worked only for
InnoDB, even for storage engines with the
requisite underlying capabilities.
(Bug #68469, Bug #16391678)
mysql_install_db incorrectly tried to create
mysql.innodb_index_stats tables if
InnoDB was not available.
(Bug #68438, Bug #16369955)
mysqldump assumed the existence of the
tables in the
mysql database. It failed if
invoked to dump tables from an older server where these tables
do not exist.
(Bug #65670, Bug #14236170)
Attempts to build from a source RPM package could fail because
the build process attempted to refer to a
pb2user that might not exist.
(Bug #64641, Bug #13865797, Bug #69339, Bug #16874980)
If one session had any metadata lock on a table, another session
CREATE TABLE [IF NOT EXISTS] for
the same table would hang. This occurred due to an attempt in
the second session to acquire an exclusive metadata lock on the
table before checking whether the table already existed. An
exclusive metadata lock is not compatible with any other
metadata locks, so the session hung for the lock timeout period
if another session had the table locked.
Now the server attempts to acquire a shared metadata lock on the
table first to check whether it exists, then upgrade to an
exclusive lock if it does not. If the table does exist, an error
CREATE TABLE and a warning for
CREATE TABLE IF NOT EXISTS.
(Bug #63144, Bug #13418638)
sql-common/client_plugin.c contained a
nonportable use of a
(Bug #62769, Bug #13252623)
Unoptimized versions of the
my_global.h were used on 64-bit x86
(Bug #61179, Bug #12565703)
A typo in
DTrace support from being enabled by
(Bug #60743, Bug #12325449)
Boolean plugin system variables did not behave well on machines
char is unsigned; some code attempted
to assign a negative value to these.
(Bug #59905, Bug #11864205)
big_tables enabled, queries that used
COUNT(DISTINCT) on a simple join with a
constant equality condition on a non-duplicate key returned
(Bug #52582, Bug #11760197)
References: See also Bug #18853696.