Functionality Added or Changed
mysqlbinlog now supports
options to display row events as commented SQL statements. (The
default otherwise is to display row events encoded as base-64
See mysqlbinlog Row Event Display.
SHOW PROFILES and
SHOW PROFILE statements to
display statement profile data, and the accompanying
Profiling is controlled using the
variables. see SHOW PROFILES Syntax, and
INFORMATION_SCHEMA PROFILING Table. (Community contribution by
The profiling feature is enabled using the
to configure. These options are enabled by
default; to disable them, use
MySQL source distributions are now available in Zip format. (Bug #27742)
Security Fix; Important Change: Additional corrections were made for the symlink-related privilege problem originally addressed in MySQL 5.1.24. The original fix did not correctly handle the data directory path name if it contained symlinked directories in its path, and the check was made only at table-creation time, not at table-opening time later.
Additional fixes were made in MySQL 5.1.41.
(Bug #32167, CVE-2008-2079)
References: See also Bug #39277.
The server consumed excess memory while parsing statements with
hundreds or thousands of nested boolean conditions (such as
OR (OR ... (OR ... ))). This could lead to a
server crash or incorrect statement execution, or cause other
client statements to fail due to lack of memory. The latter
result constitutes a denial of service.
Performance; Incompatible Change:
Some performance problems of
SHOW ENGINE INNODB
STATUS were reduced by removing
Total number of lock structs in row
lock hash table from the output. Now these values are
present only if the
UNIV_DEBUG symbol is
defined at MySQL build time.
(Bug #36941, Bug #36942)
Over-aggressive lock acquisition by
when calculating free space for tablespaces could result in
performance degradation when multiple threads were executing
statements on multi-core machines.
SHOW STATUS took a lot of CPU
time for calculating the value of the
status variable. Now this variable is calculated and included in
the output of
SHOW STATUS only if
UNIV_DEBUG symbol is defined at MySQL
There were some problems using
hook functions on Windows that automatically do global and
per-thread initialization for
Per-thread initialization: MySQL internally counts the
number of active threads, which causes a delay in
my_end() if not all threads have
exited. But there are threads that can be started either by
Windows internally (often in TCP/IP scenarios) or by users.
Those threads do not necessarily use
libmysql.dll functionality but still
contribute to the open-thread count. (One symptom is a
five-second delay in times for PHP scripts to finish.)
WSAStartup that itself loads DLLs and
can lead to a deadlock in the Windows loader.
To correct these problems, DLL initialization code now is not
libmysql.dll by default. To
obtain the previous behavior (DLL initialization code will be
called), set the
variable to any value. This variable exists only to prevent
breakage of existing Windows-only applications that do not call
mysql_thread_init() and work
okay today. Use of
discouraged and is removed in MySQL 6.0.
(Bug #37226, Bug #33031)
An additional correction to the original MySQL 5.1.23 fix was
made to normalize directory names before adding them to the list
of directories. This prevents
/etc from being considered different, for
References: See also Bug #38180.
When a partitioned table had a
TIMESTAMP column defined with
CURRENT_TIMESTAMP as the default but with no
ON UPDATE clause, the column's value was
incorrectly set to
updating across partitions.
table returned erroneous results when an index was present on a
column in the
WHERE clause and
IN was used on that column.
Searches using the index were also much slower then if the index were not present. (Bug #35931)
SELECT COUNT(*) was not correct for some
partitioned tables using a storage engine that did not support
HA_STATS_RECORDS_IS_EXACT. Tables using the
ARCHIVE storage engine were known to be
This was because
not implemented, and so the default
handler::records() was used in its place.
However, this is not correct behavior if the storage engine does
The solution was to implement
ha_partition::records() as a wrapper around
the underlying partition records.
As a result of this fix, the rows column in the output of
PARTITIONS now includes the total number of records in
the partitioned table.
When one user was in the midst of a transaction on a partitioned
table, a second user performing an
TABLE on this table caused the server to hang.
MyISAM recovery enabled with the
--myisam-recover option did not
work for partitioned
myisamchk failed with an assertion error when
analyzing a partitioned
Attempting to execute an
DELAYED statement on a partitioned table produced the
error Table storage engine for
table' doesn't have this
option, which did not reflect the source of the
error accurately. The error message returned in such cases has
been changed to DELAYED option not supported for
These statements are not replicated; however, when using
row-based logging, the changes they introduce in the
mysql system tables are written to the
Replication: Some kinds of internal errors, such as Out of memory errors, could cause the server to crash when replicating statements with user variables.
certain internal errors. (Bug #37150)
Row-based replication did not correctly copy
TIMESTAMP values from a
big-endian storage engine to a little-endian storage engine.
UUID() function returned
UUIDs with the wrong time; this was because the offset for the
time part in UUIDs was miscalculated.
mysqlbinlog left temporary files on the disk after shutdown, leading to the pollution of the temporary directory, which eventually caused mysqlbinlog to fail. This caused problems in testing and other situations where mysqlbinlog might be invoked many times in a relatively short period of time. (Bug #35543)
InnoDB tables, the
DATA_FREE column of the
free space in kilobytes rather than bytes. Now it displays
The mysql client failed to recognize comment
lines consisting of
-- followed by a newline.
If the length of a field was 3, internal
InnoDB to integer type conversion didn't work
on big-endian machines in the
The fix for Bug #20748 caused a problem such that on Unix, MySQL
programs looked for options in
rather than the standard location of
Freeing of an internal parser stack during parsing of complex stored programs caused a server crash. (Bug #35577, Bug #37269, Bug #37228)
ORDER BY ...
DESC sometimes returned results in ascending order.
Index scans performed with the
access method returned wrong results, caused memory to be
leaked, and caused temporary files to be deleted when the limit
(Bug #35477, Bug #35478)
DISTINCT from a simple view on an
InnoDB table, where all selected columns
belong to the same unique index key, returned incorrect results.
Cached queries that used 256 or more tables were not properly
cached, so that later query invalidation due to a
TRUNCATE TABLE for one of the
tables caused the server to hang.
The internal functions
my_micro_time_and_time() did not work
correctly on Windows. One symptom was that uniqueness of
UUID() values could be
ALTER TABLE operations were
not fast for columns that used multibyte character sets.
REPLACE statements used
“traditional” style locking, regardless of the
REPLACE works the same way as
“simple inserts” instead of using the old locking
are treated in the same way as
Setting the session value of the
variable caused a server crash.
A significant slowdown occurred when many
SELECT statements that return
many rows from
InnoDB tables were running
mysql_install_db failed if the server was
running with an SQL mode of
TRADITIONAL. This program now
resets the SQL mode internally to avoid this problem.
The server returned unexpected results if a right side of the
NOT IN clause consisted of the
NULL value and some constants of the same
type. For example, this query might return 3, 4, 5, and so forth
if a table contained those values:
SELECT * FROM t WHERE NOT t.id IN (NULL, 1, 2);
Server-side cursors were not initialized properly, which could cause a server crash. (Bug #38486)
The configure script did not permit
utf8_hungarian_ci to be specified as the
max_length result set metadata value was
calculated incorrectly under some circumstances.
Within stored programs or prepared statements,
REGEXP could return incorrect
results due to improper initialization.
On 64-bit systems, assigning values of 2
63 – 1 or larger to
key_buffer_size caused memory
The server could crash with an assertion failure (or cause the client to get a “Packets out of order” error) when the expected query result was that it should terminate with a “Subquery returns more than 1 row” error. (Bug #36135)
Dumping information about locks in use by sending a
SIGHUP signal to the server or by invoking
the mysqladmin debug command could lead to a
server crash in debug builds or to undefined behavior in
A failure to clean up binary log events was corrected (detected by Valgrind). (Bug #38290)
A server crash or Valgrind warnings could result when a stored procedure selected from a view that referenced a function. (Bug #38291)
TRUNCATE TABLE for an
InnoDB table, inserting explicit values into
AUTO_INCREMENT column could fail to
increment the counter and result in a duplicate-key error for
subsequent insertion of
CSV storage engine returned success even
when it failed to open a table's data file.
When the fractional part in a multiplication of
DECIMAL values overflowed, the
server truncated the first operand rather than the longest. Now
the server truncates so as to produce more precise
If initialization of an
freed some internal plugin data twice.
MyISAM table with
ROW_FORMAT = DYNAMIC table
options, a data consistency check (maximum record length) could
fail and cause the table to be marked as corrupted.
Table checksum calculation could cause a server crash for
FEDERATED tables with
BLOB columns containing
When using indexed
ORDER BY sorting,
incorrect query results could be produced if the optimizer
switched from a covering index to a noncovering index.
Incorrect handling of aggregate functions when loose index scan was used caused a server crash. (Bug #38195)
If a table has a
BIT NOT NULL column
c1 with a length shorter than 8 bits and some
NOT NULL columns
c2, ..., and a
SELECT query has a
WHERE clause of the form
query could return an unexpected result set.
constant) AND c2 ...
Changes to build files were made to enable the MySQL distribution to compile on Microsoft Visual C++ Express 2008. (Bug #33907)
A query which had an
ORDER BY DESC clause
that is satisfied with a reverse range scan could cause a server
crash for some specific CPU/compiler combinations.
Queries containing a subquery with
ORDER BY could cause a server crash.
mysql_install_db failed if the default
storage engine was
NDB. Now it
MyISAM as the storage engine
when running mysqld --bootstrap.
TRUNCATE TABLE for
InnoDB tables returned a count showing too
many rows affected. Now the statement returns 0 for
In some cases, the parser interpreted the
character as the end of input and misinterpreted stored program
After executing a prepared statement that accesses a stored function, the next execution would fail to find the function if the stored function cache was flushed in the meantime. (Bug #12093, Bug #21294)
The Serbian translation for the
error was corrected.
PRIVILEGES statement did not produce an error when it
mysql_upgrade attempted to use the
/proc file system even on systems that do
not have it.
Several MySQL programs could fail if the
environment variable had an empty value.
The BUILD/check-cpu build script failed if gcc had a different name (such as gcc.real on Debian). (Bug #27526)
On NetWare, mysql_install_db could appear to execute normally even if it failed to create the initial databases. (Bug #30129)