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.
Audit Log Plugin Notes
MySQL 5.7 changed audit log file output to a new format that has
better compatibility with Oracle Audit Vault. This format has
been backported to MySQL 5.6 and it is possible to select either
the old or new format using the new
variable, which has permitted values of
details about each format, see The Audit Log File.
In addition, when the audit log plugin rotates the audit log
file, it uses a different file name format. For a log file named
audit.log, the plugin previously renamed
the file to
The plugin now renames the file to
to indicate that it is an XML file.
If you change the value of
audit_log_format, use this
procedure to avoid writing log entries in one format to an
existing log file that contains entries in a different format:
Stop the server.
Rename the current audit log file manually.
Restart the server with the new value of
audit_log_format. The audit
log plugin will create a new log file, which will contain
log entries in the selected format.
The API for writing audit plugins has also changed. The
mysql_event_general structure has new members
to represent client host name and IP address, command class, and
external user. For more information, see
Writing Audit Plugins.
Functionality Added or Changed
In MySQL 5.6.13, the
statement instrument in the Performance Schema
setup_instruments table was renamed
statement/com/new_packet. That change has
Applications that refer to the old instrument name must be updated with the new name. For more information about the use of abstract instruments in statement classification, see Performance Schema Statement Event Tables. (Bug #16750433, Bug #17271055)
plugin now supports inserts and reads on mapped
InnoDB tables that have an
INTEGER defined as the primary key.
(Bug #17315083, Bug #17203937)
Important Change; Replication:
START SLAVE UNTIL SQL_AFTER_GTIDS did not
cause the slave to stop until the next GTID event was received
following execution of the transaction having the indicated
GTID, which could cause issues in the case when the next GTID
event is delayed, or does not exist. Now the slave stops after
completing the transaction with that GTID.
Following any query on the
InnoDB index statistics as
shown in the output of statements such as
read from the last partition, instead of from the partition
containing the greatest number of rows.
(Bug #11766851, Bug #60071)
References: See also Bug #16882435, Bug #69179.
When logging the delete-marking of a record during online
InnoDB writes the
transaction ID to the log as it was before the deletion or
delete-marking of the record. When doing this,
InnoDB would overwrite the
DB_TRX_ID field in the original table, which
could result in locking issues.
would incorrectly prepare to compare a NULL column prefix in a
secondary index with a non-NULL column in a clustered index.
An assertion would be raised in
fil_node_open_file due to a missing
.ibd file. Instead of asserting,
InnoDB should return false and the caller of
fil_node_open_file should handle the return
(Bug #17305626, Bug #70007)
InnoDB: An incorrect purge would occur when rolling back an update to a delete-marked record. (Bug #17302896)
ut_ad(oldest_lsn <= cur_lsn)
buf0flu.cc failed because the
current max LSN would be retrieved from the buffer pool before
the oldest LSN.
would perform more slowly than SQL
As commented in
should only be compiled when
(Bug #17160270, Bug #69724)
InnoDB would rename a user-defined foreign
key constraint containing the string “_ibfk_” in
its name, resulting in a duplicate constraint.
(Bug #17076737, Bug #69693, Bug #17076718, Bug #69707)
ha_innobase::clone function would
incorrectly assert that a thread cannot clone a table handler
that is used by another thread, and that the original table
handler and the cloned table handler must belong to the same
transaction. The incorrect assertions have been removed.
InnoDB: A regression introduced in the fix for Bug #14606334 would cause crashes on startup during crash recovery. (Bug #16996584)
Rolling back an
INSERT after a
BLOB write would result in
an assertion failure. The assertion has been modified to allow
BLOB pointers if an error
occurs during a
When dropping all indexes on a column with multiple indexes,
InnoDB failed to block a
DROP INDEX operation when a
foreign key constraint requires an index.
An assertion failure would occur in file
ROW_FORMAT=REDUNDANT tables that contained an
unexpected but valid data directory flag.
A regression introduced with the fix for Bug #11762038 would
InnoDB to raise an incorrect error
message. The message stated that, “InnoDB cannot
delete/update rows with cascading foreign key constraints that
exceed max depth of 20”. The error message would occur
when killing connections reading from
tables that did not have foreign key constraints.
In debug builds, an assertion failure would occur if
not exist. Instead of an assertion,
now aborts with an error message if
(Bug #16691130, Bug #69000)
InnoDB: For the Barracuda file format and beyond, the externally stored prefix would be read even though the prefix is already stored locally in memory. (Bug #16569640)
When changing the shared tablespace file name using
leaving the current log files in place,
InnoDB would create a new tablespace file and
overwrite the log files resulting in a mismatch between the data
dictionary and tables on disk. This bug fix ensures that
InnoDB does not create a new tablespace if
there are inconsistent system tablespaces, undo tablespaces, or
redo log files.
Persistent stats would be disabled unnecessarily when running in
read-only mode. When running in read-only mode, fetching stats
from disk does not involve any modification of on-disk data
except for when
ANALYZE TABLE is
run. This fix enables persistent stats for read-only mode.
The documentation incorrectly stated that
START TRANSACTION WITH
CONSISTENT SNAPSHOT provides a consistent snapshot
only if the current isolation level is
REPEATABLE READ or
START TRANSACTION WITH
CONSISTENT SNAPSHOT only works with
REPEATABLE READ. All other
isolation levels are ignored. The documentation has been revised
and a warning is now generated whenever the
SNAPSHOT clause is ignored.
(Bug #14017206, Bug #65146)
srv_master_thread background thread,
which monitors server activity and performs activities such as
page flushing when the server is inactive or in a shutdown
state, runs on a one second delay loop.
srv_master_thread failed to check if the
server is in a shutdown state before sleeping.
(Bug #13417564, Bug #63276)
An infinite loop could occur in
buf_page_get_gen when handling
(Bug #12560151, Bug #61132)
Creating a table
CREATE TABLE ...
PARTITION BY LIST ... PARTITION ... VALUES IN (NULL),
then attempting to execute
CREATE TABLE ...
LIKE t1 caused the server to fail.
The server attempted to perform an internal truncatation of the
slave_worker_info table while resetting it,
even though this is a DDL operation and should not be used
conccurrently with DML operations. To prevent this from
happening, the reset now performs sequential row deletion in
place of the truncation operation.
(Bug #17286858, Bug #69898)
Replication: The commit error caused by the failure of binary log rotation failure generated an incident event in the binary log file and interrupted the user session with error messages which did not mention that the slave server would be stopped later when the incident event was replayed.
Now, when encountering binary log rotation failure, a more helpful error message is instead written to the log, alerting the user to investigate in a timely manner. (Bug #17016017)
It was possible in
TO statements to set the
MASTER_DELAY option greater than the
supported maximum value (
– 1). In addition, the error resulting from
MASTER_DELAY to a value greater than
232 was not
(Bug #16820156, Bug #16960315, Bug #69249, Bug #69469)
When a master with semisynchronous replication enabled was shut
down, the master failed to wait for either a semisyncnronous
ACK or timeout before completing the
shutdown. This prevented semisynchronous replication from
reverting to asynchronous replication and allowed open
transactions to complete on the master, which resulted in
missing events on the slave.
To fix this problem, dump threads are now stopped last during shutdown, after the client is told to stop, so that, if the dump thread has pending events from active clients, they can be sent to the slave. (Bug #16775543)
Replication: A session attachment error during group commit causes the rollback of the transaction (as intended), but the transaction in which this happened was still written to the binary log and replicated to the slave. Thus, such an error could lead to a mismatched master and slave.
Now when this error occurs, an incident event is written in the binary log which causes replication to stop, and notifies the user that redundant events may exist in the binary log. An additional error is also now reported to the client, indicating that the ongoing transaction has been rolled back. (Bug #16579083)
START SLAVE failed when the
server was started with the options
autocommit set to 0,
A workaround for previous versions of MySQL is to restart the
slave mysqld without the
A slave using row-based replication was unable to read the rows
containing columns of type
properly (old-style decimal, used prior to MySQL 5.0.3). Now the
slave throws an error if it receives this type of data. You can
convert the old-style
format to the binary format used in current MySQL releases with
ALTER TABLE; see
from MySQL 4.1 to 5.0, for more information.
DROP TEMP TABLE IF
EXISTS statements could lead to failures in applying
the binary log during point-in-time recovery operations. This is
due to the fact that, when using row-based replication, the
IF EXISTS to any
TEMPORARY TABLE statements written to the binary log,
and that the slave SQL thread does not check * wildcard filter
DROP TEMPORARY TABLE IF EXISTS. If
--log-slave-updates was also
enabled on the slave, such a statement was preceded by a
USE statement. If the database
referred by the
USE statement did not exist,
the statement failed, and stopped replication.
Now, when writing
DROP TEMPORARY TABLE IF
EXISTS into the binary log, no
statement is written, and the table name in the
TEMPORARY TABLE statement is a fully qualified table
References: This bug is a regression of Bug #14188793.
mysql_real_connect() C API
function could leak memory if it failed.
Full-text search on
InnoDB tables failed on
searches that used the
+ boolean operator.
For single-threaded workloads, the optimizer recognizes some special cases for which it can avoid function calls and enhance performance. (Bug #17234723)
SELECT * from
raise an assertion due to a race condition under load.
InnoDB full-text searches failed in databases
whose names began with a digit.
A successful connection failed to reset the per-IP address
counter used to count successive connection failures. This could
possibly cause a host to be blocked, when the
max_connect_errors limit was
With the thread pool plugin enabled and SSL in use, an error in one connection might affect other connections, causing them to experience a lost connection. (Bug #17087862)
Under load, truncating the
Performance Schema table could cause a server exit.
Within a stored program, comparison of the value of a scalar
subquery with an
IN clause resulted in an
error for the first execution and raised an assertion for the
my_strtoll10() function could incorrectly
convert some long string-format numbers to numeric values and
fail to set the overflow flag.
A race condition in the thread pool plugin could cause status
variables such as
Aborted_connects not to be
incremented and permitting concurrent kills to happen for the
same thread ID.
For partitioned tables, queries could return different results depending on whether Index Merge was used. (Bug #16862316)
References: See also Bug #17648468, Bug #176588348, Bug #18167648.
Excessive memory consumption was observed for multiple execution of a stored procedure under these circumstances: 1) The stored procedure had an SQL statement that failed during validation. 2) The stored procedure had an SQL statement that required repreparation. (Bug #16857395)
For some statements, memory leaks could result when the optimizer removed unneeded subquery clauses. (Bug #16807641)
References: This bug is a regression of Bug #15875919.
Password rewriting in the general query log now also applies to prepared statements. (Bug #16732621)
Within a stored procedure, repeated execution of a prepared
CREATE TABLE statement for a
table with partitions could cause a server exit.
For debug builds, when the optimizer removed an
Item_ref pointing to a subquery, it caused a
References: This bug is a regression of Bug #16318585.
If the primary key for the
table was removed (an unsupported and not-recommended
operation), the server exited for subsequent stored procedure
invocation. Similar problems could occur for other system
tables. Now an error occurs instead.
Deadlocks involving metadata locks and
deadlocks were both reported as an
ER_LOCK_DEADLOCK error, but only
InnoDB deadlocks rolled back the transaction.
Now both deadlocks roll back the transaction.
Metadata returned for a prepared
statement that had outer joins could indicate that columns
NULL values were
For queries that accessed an
INFORMATION_SCHEMA table in a subquery, an
attempt to lock a mutex that had already been locked could cause
a server crash.
Full-text search on
InnoDB tables failed on
searches for words containing apostrophes when using boolean
(Bug #69932, Bug #17276125)
InnoDB deadlock caused transaction rollback
but did not release metadata locks, blocking concurrent DDL on
the transaction tables until the connection that got the
deadlock issued an explicit
(Bug #69668, Bug #17054007)
libmysql.dll library was missing
(Bug #69204, Bug #16797982, Bug #62394)
SET OPTION, which failed when
reloaded because the deprecated
keyword has been removed from
(Bug #67507, Bug #15844882)
For failure to create a new thread for the event scheduler, event execution, or new connection, no message was written to the error log. This could lead to the impression that the event scheduler was running normally when it was not. (Bug #67191, Bug #14749800, Bug #16865959)
If one connection changed its default database and
simultaneously another connection executed
PROCESSLIST, the second connection could access
invalid memory when attempting to display the first connection's
default database. memory.
(Bug #58198, Bug #11765252)
For better robustness against stack overflow, the server now accounts for the size of the guard area when making thread stack size requests. (Bug #35019, Bug #11748074)