Functionality Added or Changed
Security Fix; Partitioning:
Accessing a table having user-defined partitioning when the
server SQL mode included
ONLY_FULL_GROUP_BY caused the
MySQL server to crash. For example, the following sequence of
statements crashed the server:
DROP TABLE IF EXISTS t1; SET SESSION sql_mode='ONLY_FULL_GROUP_BY'; CREATE TABLE t1 (id INT, KEY(id)) PARTITION BY HASH(id) PARTITIONS 2;
strxnmov() library function could write a
null byte after the end of the destination buffer.
InnoDB tables, MySQL used a
less-selective secondary index to avoid a filesort even if a
prefix of the primary key was much more selective.
The fix for this problem might cause other queries to run more slowly. (Bug #45828)
Important Change; Replication:
MIXED binary logging format, a statement that
changes both nontransactional and transactional tables must be
written to the binary log whenever there are changes to
nontransactional tables. This means that the statement goes into
the binary log even when the changes to the transactional tables
fail. In particular, in the event of a failure such statement is
annotated with the error number and wrapped inside a pair of
On the slave, while applying the statement, it is expected that the same failure and the rollback prevent the transactional changes from persisting. However, statements that fail due to concurrency issues such as deadlocks and timeouts are logged in the same way, causing the slave to stop since the statements are applied sequentially by the SQL thread.
Truncating a partitioned
MyISAM table did not
LIMIT generated spurious
Statement is not safe to log in statement
format warnings in the error log, causing the log to
grow rapidly in size.
References: See also Bug #46265, Bug #42415. This bug was introduced by Bug #34768.
The internal function
not propagate an error occurring in another internal function
SHOW SLAVE STATUS connection
thread competed with the slave SQL thread for use of the error
message buffer. As a result, the connection thread sometimes
received incomplete messages. This issue was uncovered with
valgrind when message strings were passed
NULL terminators, causing the error
Conditional jump or move depends on uninitialized
References: See also Bug #43076.
Large transactions and statements could corrupt the binary log
if the size of the cache (as set by
max_binlog_cache_size) was not
large enough to store the changes.
Now, for transactions that do not fit into the cache, the statement is not logged, and the statement generates an error instead.
For nontransactional changes that do not fit into the cache, the statement is also not logged—an incident event is logged after committing or rolling back any pending transaction, and the statement then raises an error.
If a failure occurs before the incident event is written the binary log, the slave does not stop, and the master does not report any errors.
(Bug #43929, Bug #11752675)
References: See also Bug #37148, Bug #11748696, Bug #46166, Bug #11754544.
--database option for
mysqlbinlog was ignored when using the
row-based logging format.
Replication: When reading a binary log that was in use by a master or that had not been properly closed (possibly due to a crash), the following message was printed: Warning: this binlog was not closed properly. Most probably mysqld crashed writing it. This message did not take into account the possibility that the file was merely in use by the master, which caused some users concern who were not aware that this could happen.
To make this clear, the original message has been replaced with Warning: this binlog is either is use or was not closed properly. (Bug #34687)
For replication of a stored procedure that uses the
gbk character set, the result on the master
and slave differed.
Invalid memory reads and writes were generated when altering merge and base tables. This could lead to a crash or Valgrind errors:
==28038== Invalid write of size 1 at: memset (mc_replace_strmem.c:479) by: myrg_attach_children (myrg_open.c:433) by: ha_myisammrg::attach_children() (ha_myisammrg.cc:546) by: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944) by: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147) by: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709) by: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977) by: open_n_lock_single_table (mysql_priv.h:1550) by: mysql_alter_table(sql_table.cc:6428) by: mysql_execute_command(THD*) (sql_parse.cc:2860) by: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933) by: dispatch_command (sql_parse.cc:1213)
Some collations were causing
report inaccurate key range estimations to the optimizer for
LIKE clauses that select substrings. This can
be seen by running
problem primarily affects multibyte and unicode character sets.
When creating tables using the
storage engine with the
ibmdb2i_create_index_option option set to 1,
IBMDB2I table with a primary key
should produce an additional index that uses EBCDIC hexadecimal
sorting, but this index was not created.
Inserting data into a table using the
character set with the
IBMDB2I storage engine
If an error occurred during the creation of a table (for
example, the table already existed) having an
AUTO_INCREMENT column and a
BEFORE trigger that used the
SELECT construct, an internal flag was not reset
properly. This led to a crash the next time the table was opened
There was a race condition when changing
runtime to the value
References: See also Bug #42101.
For queries with a sufficient number of subqueries in the
FROM clause of this form:
SELECT * FROM (SELECT 1) AS t1, (SELECT 2) AS t2, (SELECT 3) AS t3, ...
The query failed with a
Too high level of nesting for
select error, as though the query had this form:
SELECT * FROM (SELECT 1 FROM (SELECT 2 FROM (SELECT 3 FROM ...
The server crashed if evaluation of
GROUP_CONCAT(... ORDER BY)
required allocation of a sort buffer but allocation failed.
When reading binary data, the concatenation function for geometry data collections did not rigorously check for available data, leading to invalid reads and server crashes. (Bug #44684)
Valgrind warnings that occurred for
TABLE STATUS with
In the mysql client, if the server connection
was lost during repeated
status commands, the
client failed to detect this and command output would be
When invoked to start multiple server instances, mysqld_multi sometimes failed to start them all due to not changing location into the base directory for each instance. (Bug #36654)
InnoDB recovery could hang due to redo
logging of doublewrite buffer pages.
configure.in contained references to
literal instances of nm and
libc, rather than to variables parameterized
for the proper values on the current platform.
configure.in did not properly check for the
A workaround for a Sun Studio bug was instituted. (Bug #41710)
The mysql client could misinterpret some character sequences as commands under some circumstances. (Bug #45236)
An assertion failure could occur if
tried to unlock a record when the clustered index record was
options (for example,
--enable-innodb) did not
References: See also Bug #19027.
Performing an empty XA transaction caused the server to crash for the next XA transaction. (Bug #45548)
Rows written to the slow query log could have an indeterminate
Rows_examined value due to improper
A Valgrind error during subquery execution was corrected. (Bug #36995)
UPDATE statements that
affected no rows returned a rows-affected count of one.
The optimizer mishandled “impossible range” conditions and returned empty results due to an uninitialized variable. (Bug #45266)
SHOW ERRORS returned an empty
result set after an attempt to drop a nonexistent table.
Renaming a column that appeared in a foreign key definition did not update the foreign key definition with the new column name. (Bug #21704)