This is a milestone release, for use at your own risk. Significant development changes take place in milestone releases and you may encounter compatibility issues, such as data format changes that require attention in addition to the usual procedure of running mysql_upgrade. For example, you may find it necessary to dump your data with mysqldump before the upgrade and reload it afterward.
Condition Handler Changes
MySQL now supports the
DIAGNOSTICS provides applications a standardized way
to obtain information from the diagnostics area, such as whether
the previous SQL statement produced an exception and what it
was. For more information, see
GET DIAGNOSTICS Syntax.
In addition several deficiencies in condition handler processing rules were corrected so that MySQL behavior is more like standard SQL:
Block scope is used in determining which handler to select. Previously, a stored program was treated as having a single scope for handler selection.
Condition precedence is more accurately resolved.
Diagnostics area clearing has changed. Bug #55843 caused
handled conditions to be cleared from the diagnostics area
before activating the handler. This made condition
information unavailable within the handler. Now condition
information is available to the handler, which can inspect
it with the
statement. The condition information is cleared when the
handler exits, if it has not already been cleared during
Previously, handlers were activated as soon as a condition occurred. Now they are not activated until the statement in which the condition occurred finishes execution, at which point the most appropriate handler is chosen. This can make a difference for statements that raise multiple conditions, if a condition raised later during statement execution has higher precedence than an earlier condition and there are handlers in the same scope for both conditions. Previously, the handler for the first condition raised would be chosen, even if it had a lower precedence than other handlers. Now the handler for the condition with highest precedence is chosen, even if it is not the first condition raised by the statement.
Issues that caused server crashes resulting from incorrect handler call stack processing were fixed.
The work just described involved several condition-handler bug fixes:
RETURN statement did not
clear the diagnostics area as it should have. Now the
diagnostics area is cleared before executing
RETURN. This prevents a
condition in a nested function call from incorrectly
propagating to an outer scope. It also means there is no way
to return an SQL warning from a stored function. This change
is not backward compatible, but the resulting behavior is
more like standard SQL.
When an SQL
HANDLER was activated, the
handled condition was immediately removed from the
diagnostics area. Consequently, any SQL diagnostic statement
executed in the handler was unable to examine the condition
that triggered the handler.
If multiple handlers existed at the same level within a stored program, the wrong one could be chosen.
If an error occurred in a context where different handlers were present at different levels of nesting, an outer handler could be chosen rather than the innermost one.
For more information, see Scope Rules for Handlers. (Bug #12951117, Bug #38806, Bug #11749343, Bug #55852, Bug #11763171, Bug #61392, Bug #12652873, Bug #11660, Bug #11745196, Bug #48637, Bug #11756690)
Fractional Seconds Handling
MySQL now permits fractional seconds for
TIMESTAMP values, with up to
microseconds (6 digits) precision. To define a column that
includes a fractional seconds part, use the syntax
fsp is the fractional seconds
precision. For example:
CREATE TABLE t1 (t TIME(3), dt DATETIME(6));
fsp value, if given, must be in
the range 0 to 6. A value of 0 signifies that there is no
fractional part. If omitted, the default precision is 0. (This
differs from the standard SQL default of 6, for compatibility
with previous MySQL versions.)
The following items summarize the implications of this change. See also Fractional Seconds in Time Values.
TIMESTAMP columns, the
encoding and storage requirements in new tables differ from
such columns in tables created previously because these
types now include a fractional seconds part.
Due to changes to encoding and storage requirements for
TIMESTAMP types, importing
InnoDB tables that
TIMESTAMP types into MySQL
5.6.4 (or later) requires a workaround procedure which is
described in the “Server Changes” section of
Upgrading from MySQL 5.5 to 5.6 .
Syntax for temporal literals now produces temporal values:
', and the
ODBC-syntax equivalents. The resulting value includes a
trailing fractional seconds part if specified. Previously,
the temporal type keyword was ignored and these constructs
produced the string value. See
Standard SQL and ODBC Date and Time Literals
Functions that take temporal arguments accept values with fractional seconds. Return values from temporal functions include fractional seconds as appropriate.
ROUTINES, now have a
DATETIME_PRECISION column. Its value is
the fractional seconds precision for
TIMESTAMP columns, and
NULL for other data types.
The C API accommodates fractional seconds as follows:
MYSQL_FIELD column metadata
indicates the fractional seconds precision for
Clients can determine whether a result set temporal
column has a fractional seconds part by checking for a
decimals value in the
indicated the precision for numeric columns and was zero
MYSQL_TIME structure used for
the binary protocol, the
member indicates the microseconds part for
In some cases, previously accepted syntax may produce different results. The following items indicate where existing code may need to be changed to avoid problems:
Some expressions produce results that differ from previous
results. Examples: The
timestamp system variable
returns a value that includes a microseconds fractional part
rather than an integer value. Functions that return a result
that includes the current time (such as
UTC_TIMESTAMP()) interpret an
argument as an
fsp value and the
return value includes a fractional seconds part of that many
digits. Previously, these functions permitted an argument
but ignored it.
TIME values are converted to
DATETIME by adding the time
to the current date. (This means that the date part of the
result differs from the current date if the time value is
outside the range from
'23:59:59'.) Previously, conversion of
TIME values to
DATETIME was unreliable. See
Conversion Between Date and Time Types.
was permitted in old MySQL versions, but
N was a display width rather than
fractional seconds precision. Support for this behavior was
removed in MySQL 5.5.3, so applications that are reasonably
up to date should not be subject to this issue. Otherwise,
code must be rewritten.
There may be problems replicating from a master server that understands fractional seconds to an older slave that does not:
CREATE TABLE statements
containing columns that have an
fsp value greater than 0,
replication will fail due to parser errors.
Statements that use temporal data types with an
fsp value of 0 will work for
with statement-based logging but not row-based logging. In
the latter case, the data types have binary formats and
type codes on the master that differ from those on the
Some expression results will differ on master and slave.
For example, expressions that involve the
timestamp system variable or functions
that return the current time have different results, as
(Bug #8523, Bug #11745064)
MySQL now supports
FULLTEXT indexes for
InnoDB tables. The core syntax is very
similar to the
FULLTEXT capability from
earlier releases, with the
MATCH() ... AGAINST() clause
SELECT statement. The new
@ operator allows proximity searches for
terms that are near each other in the document. The detailed
search processing is controlled by a new set of configuration
can monitor the workings of the
full-text search system by querying new
These query optimizer improvements were implemented:
The optimizer detects and optimizes away these useless query
GROUP BY, if there is no
HAVING clause and no aggregate
ORDER BY, which has no effect because
LIMIT is not supported in these
Performance Schema Notes
The Performance Schema has these additions:
The Performance Schema now permits instrument and consumer
configuration at server startup, which previously was
possible only at runtime using
UPDATE statements for the
setup_consumers tables. This
change was made because configuration at runtime is too late
to disable instruments that have already been initialized
during server startup. For example, the
wait/sync/mutex/sql/LOCK_open mutex is
initialized once during server startup, so attempts to
disable the corresponding instrument at runtime have no
To control an instrument at server startup, use an option of this form:
instrument_name is an
instrument name such as
value is one of these values:
0: Disable the instrument
1: Enable and time the instrument
counted: Enable and count (rather
than time) the instrument
option can specify only one instrument name, but multiple
instances of the option can be given to configure multiple
instruments. In addition, patterns are permitted in
instrument names to configure instruments that match the
pattern. To configure all condition synchronization
instruments as enabled and counted, use this option:
To disable all instruments, use this option:
Longer instrument name strings take precedence over shorter pattern names, regardless of order. For information about specifying patterns to select instruments, see Naming Instruments or Consumers for Filtering Operations.
An unrecognized instrument name is ignored. It is possible that a plugin installed later may create the instrument, at which time the name is recognized and configured.
To control a consumer at server startup, use an option of this form:
consumer_name is a consumer
name such as
value is one of these values:
0: Do not collect events for the
1: Collect events for the consumer
For example, to enable the
events_waits_history consumer, use this
The permitted consumer names can be found by examining the
setup_consumers table. Patterns
are not permitted.
Along with the preceding changes to permit configuration at server startup, the default instrument and consumer configuration has changed. Previously, all instruments and consumers were enabled by default. Now, instruments are disabled except the statement, I/O, and idle instruments. Consumers are disabled except the global, thread, and current-statement consumers. These changes produce a default configuration with a low overhead.
Tables that have an
EVENT_ID column now
also have an
END_EVENT_ID column to
support determination of nested event relationships:
EVENT_ID is populated with the
thread current event counter when an event starts. In
NULL until the event ends, at which point
it is set to the new thread current event counter. This
permits the relationship “event B is included in event
A” to be determined using the following expression,
without having to follow each inclusion relationship using
A.EVENT_ID <= B.EVENT_ID AND B.END_EVENT_ID <= A.END_EVENT_ID
The Performance Schema aggregates file I/O operations in two
tables and the
tables. It was possible to join the
table to the
EVENT_NAME column. However, it
was not possible to do the same with the
tables because the former uses
OBJECT_INSTANCE_BEGIN as the instance
identifier and the latter uses
This means that it was possible to obtain both file I/O
latency and usage per file, but not to correctly correlate
latency to usage when there was more than one form of file
(such as multiple redo logs, table files, and so forth).
To address this issue, the
now has an
In addition, both
additional aggregation columns (such as timer wait
information), which in many cases makes it possible to
obtain the desired summary information without need for a
join at all.
If you upgrade to this release of MySQL from an earlier version,
you must run mysql_upgrade (and restart the
server) to incorporate these changes into the
For more information, see MySQL Performance Schema.
Functionality Added or Changed
You can now set the
page size for uncompressed
tables to 8KB or 4KB, as an alternative to the default 16KB.
This setting is controlled by the
option. You specify the size when creating the MySQL instance.
tablespaces within an
instance share the same page size. Smaller page sizes can help
to avoid redundant or inefficient I/O for certain combinations
of workload and storage devices, particularly
SSD devices with small block
New optimizations apply to read-only
Optimizing InnoDB Read-Only Transactions for details. The new
InnoDB queries than before, as
a way to signal that a transaction is read-only because it is a
Previously, replication slaves could connect to the master
server only through master accounts that use native
authentication. Now replication slaves can also connect through
master accounts that use nonnative authentication if the
required client-side plugin is installed on the slave side in
the directory named by the slave
plugin_dir system variable.
The optimizer trace capability now tracks temporary tables created by the server during statement execution. (Bug #13400713)
Performance of metadata locking operations on Windows XP systems
was improved by instituting a cache for metadata lock objects.
This permits the server to avoid expensive operations for
creation and destruction of synchronization objects on XP. A new
permits control over the size of the cache. The default size is
Upgrading from an
Advanced GPL RPM package to
Advanced RPM package did not work. Now on
Linux it is possible to use rpm -U to replace
any installed MySQL product by any other of the same release
family. It is not necessary to remove the old produce with
rpm -e first.
Previously, MySQL servers from 5.1 and up refused to open
ARCHIVE tables created in 5.0
because opening them caused a server crash. The server now can
ARCHIVE tables, and
REPAIR TABLE updates them to the
format used in 5.6. However, the recommended upgrade procedure
is still to dump 5.0
before upgrading and reload them after upgrading.
(Bug #48633, Bug #11756687)
The make_win_bin_dist script is no longer used and has been removed from MySQL distributions and the manual. (Bug #58241)
Error messages that referred only to an error code now also include the corresponding error description. (Bug #48348, Bug #11756433)
The MySQL code base was changed to permit use of the C++ Standard Library and to enable exceptions and runtime type information (RTTI). This change has the following implications:
Libraries and executables depend on some C++ standard
library. On Linux, this has not been the case previously. On
Solaris, the default dependency has changed from the default
libstlport, which is now
included with binary distributions for users whose system
does not have it.
-fno-exceptions options are no longer used
to build plugins, such as storage engines. Users who write
their own plugins should omit these options if they were
C++ users who compile from source should set
CXX to a C++ compiler rather than a C
compiler. For example, use g++ rather
than gcc. This includes the server as
well as client programs.
User-defined functions can be written in C++ using standard library features.
Security Enhancement; Replication:
START SLAVE statement now
options. By default, MySQL native authentication is used, and
the user name and password are stored in the
master.info repository. This behavior can be
overridden by additionally specifying the name
DEFAULT_AUTH) and location
PLUGIN_DIR) of an authentication plugin when
START SLAVE. .
As part of this change, warnings are now issued in the following cases:
USER="..." PASSWORD="..." or
MASTER TO MASTER_USER="..." MASTER_PASSWORD="..."
is executed using an unencrypted connection, the warning
message Sending passwords in plain text without
SSL/TLS is extremely insecure is generated
If the user name and password are stored in or read from the
master.info repository in the course of
CHANGE MASTER TO, a
warning message is printed out to the error log:
Storing MySQL user name or password information
in the master.info repository is not secure and is therefore
The text of a running
SLAVE statement, including values for
be seen in the output of a concurrent
SHOW PROCESSLIST statement. The
complete text of a
TO statement is also visible to
See also Pluggable Authentication. (Bug #13083642)
The process of deallocating the
Index was made faster, during shutdown or when turning
off the AHI with the statement:
SET GLOBAL innodb_adaptive_hash_index=OFF;
(Bug #13006367, Bug #62487)
This fix improves the performance of instrumentation code for
InnoDB buffer pool operations.
(Bug #12950803, Bug #62294)
This fix improved the efficiency and concurrency of freeing
pages in the
InnoDB buffer pool when
DROP TABLE for an
InnoDB table when the
innodb_file_per_table option is
This change is most noticeable for systems with large buffer pools. During the drop operation, one traversal of the buffer pool memory structure is changed from the LRU list (the entire buffer pool) to the flush list (a much smaller structure). The LRU scanning is reduced, but not entirely eliminated. The buffer pool mutex is also released periodically, so that if the drop operation takes significant time, other threads can proceed concurrently. (Bug #11759044, Bug #51325)
Incompatible Change; Replication:
The statements in the following list are now marked as unsafe
for statement-based replication. This is due to the fact that
each of these statements depends on the results of a
SELECT statement whose order
cannot always be determined. When using
STATEMENT logging mode, a warning is issued
in the binary log for any of these statements; when using
MIXED logging mode, the statement is logged
using the row-based format.
When upgrading, you should note the use of these statements in
your applications, keeping in mind that a statement that inserts
or replaces rows obtained from a
SELECT can take up many times as
much space in the binary log when logged using row-based format
than when only the statement itself is logged. Depending on the
number and size of the rows selected and inserted (or replaced)
by any such statements, the difference in size of the binary log
after the logging of these statements is switched from
statement-based to row-based can potentially be several orders
of magnitude. See Advantages and Disadvantages of Statement-Based and Row-Based Replication.
(Bug #11758262, Bug #50439)
Previously, “Aborted connection” errors were
written to the error log based on the session value of
log_warnings, which permitted
users with minimal privileges to cause many messages to be
written to the log unless restricted by the
MAX_CONNECTIONS_PER_HOUR resource limit. Now
this logging is based on the global
log_warnings variable. There
are no remaining uses of the session
log_warnings variable, so it
has been removed and the variable now has only a global value.
(Bug #53466, Bug #11761014)
Important Change; InnoDB:
ALTER TABLE statement
failed for an
InnoDB table due to an error
code from an underlying file-renaming system call,
InnoDB could lose track of the
.ibd file for the table. This issue only
occurred when the
configuration option was enabled, and when the low-level error
persisted through thousands of retry attempts. In MySQL 5.1,
this issue applied to the InnoDB Plugin but not the built-in
InnoDB storage engine.
For example, if you encounter an error like the following:
mysql> alter table sb2 add column d2 int; ERROR 1025 (HY000): Error on rename of './sbtest/#sql-1eb9_1' to './sbtest/sb2' (errno: -1)
you might be able to access the
by copying a
.frm file from a table with an
identical schema. The table name to use for the
.frm filewould be
`sbtest.#mysql50##sql-1eb9_1` in the
(Bug #12884631, Bug #62146)
Important Change; Replication:
Setting an empty user in a
TO statement caused an invalid internal result and is
no longer permitted. Trying to use
MASTER_USER='' or setting
MASTER_PASSWORD while leaving
MASTER_USER unset causes the statement to
fail with an error.
An internal deadlock could occur within
InnoDB, on a server doing a substantial
amount of change
buffering for DML operations, particularly
Fixed a compilation problem that affected the
InnoDB source code with
gcc 4.6.1. The affected
InnoDB source file was
table could cause the server to halt with an assertion error, in
debug builds only.
Unused functions were removed from the internal
InnoDB code related to mini-transactions, to
clarify the logic.
(Bug #12626794, Bug #61240)
InnoDB: Lookups using secondary indexes could give incorrect matches under a specific set of conditions. The conditions involve an index defined on a column prefix, for a BLOB or other long column stored outside the index page, with a table using the Barracuda file format. (Bug #12601439, Bug #12543666)
UPDATE statement for an
InnoDB table could hang. The issue affects
tables using the Barracuda
file format and having multiple indexes on
column prefixes. The
size of an undo log record
could exceed the page
size, even though the total size of the column prefixes
was less than the page size (usually 16KB). In MySQL 5.5 and
higher, this error is now reported using the new code
ER_UNDO_RECORD_TOO_BIG. In MySQL
5.1 with the InnoDB Plugin, this error is reported using the
This fix corrects cases where the MySQL server could hang or
abort with a
long semaphore wait message.
(This is a different issue than when these symptoms occurred
CHECK TABLE statement.)
(Bug #11766591, Bug #59733)
DUPLICATE KEY statements for
tables from concurrent threads could cause a
deadlock, particularly with
INSERT...ON DUPLICATE KEY UPDATE form.
The problem could also be triggered by issuing multiple
statements. The fix avoids deadlocks caused by the same row
being accessed by more than one transaction. Deadlocks could
still occur when multiple rows are inserted and updated
simultaneously by different transactions in inconsistent order;
those types of deadlocks require the standard error handling on
the application side, of re-trying the transaction.
(Bug #11759688, Bug #52020, Bug #12842206)
CHECKSUM TABLE returned 0 for a
partitioned table unless the statement was used with the
(Bug #11933226, Bug #60681)
when trying to use a
FULLTEXT index with a
partitioned table, displayed the misleading text The
used table type doesn't support FULLTEXT indexes was
misleading and has been replaced with Error 1752
which shows the more accurate FULLTEXT index is not
supported for partitioned tables.
(Bug #11763825, Bug #56590)
The value set for the
variable (or the corresponding
option) was not always honored correctly; in such cases a random
value was used.
LOAD DATA on a
MyISAM table having an after-insert
trigger which wrote into an
table caused multi-threaded statement-based replication to abort
with error 1742 (Cannot execute the current event
group in the parallel mode).
Replication: Several warnings and informational messages were revised for typographic errors and clarity. (Bug #12947248, Bug #12978113)
When a statement containing a large number of rows to be applied
on a slave table that does not contain a primary key, a
considerable amount of time can be needed to find and change all
the rows that are to be changed. The current fix helps diagnose
this issue by printing a message to the error log if the
execution time for a given statement replicated using row-based
replication takes more than 60 seconds.
log_warnings must be greater
than 1 for this message to be printed to the error log.
(Bug #11760927, Bug #53375)
--hexdump printed the last
row of the hex dump incorrectly, in two ways:
If the length of the last row was eight bytes, the end of the previous row was copied to the end of the last row, padding the last row to full length.
If the length of the last row was less than sixteen bytes, its textual representation was not aligned with that of previous rows.
(Bug #11747887, Bug #34386)
Replication: A replication master could send damaged events to slaves after the binary log disk on the master became full. To correct this issue, only complete events are now pushed by the master dump thread to the slave I/O thread. In addition, the error text that the master sends to the slave when an incomplete event is found now states that the incomplete event may have been caused by running out of disk space on the master, and provides coordinates of the first and the last event bytes read. (Bug #11747416, Bug #32228)
References: See also Bug #64035, Bug #13593869.
did not work correctly when the name of the source database
from_name) consisted of only a
(Bug #34332, Bug #11747866)
InnoDB change buffering enabled and
innodb_page_size set to an 8K
or 4K page size, an
statement could fail if a column being updated contained a value
longer than 1/8th of the page size.
InnoDB assertion could cause the
server to halt. This issue only affected debug builds. The
assertion referenced the source file
btr0pcur.ic and the variable
A derived table with more than 64 columns caused a server crash. (Bug #13354889)
Writes to the slow log involved a call to
thd->current_utime() even if no log
entries ended up being written, unnecessarily reducing
Access privileges were checked for each stored program instruction, even if the instruction used no tables, resulting in reduced performance. (Bug #13251277)
The error message for
DBL_MAX, not 'inf'.
For materialized temporary tables, a missing key length check could cause incorrect query results. (Bug #13261277)
During the table-opening process, memory was allocated and later freed that was needed view loading, even for statements that did not use views. These unnecessary allocation and free operations are no longer done. (Bug #13116518)
OUTER JOIN could return
incorrect results if the subquery referred to a column from
mysql_plugin returned the wrong error code from failed server bootstrap execution. (Bug #12968567)
The Performance Schema nested some network I/O events within the wrong statement. (Bug #12981100)
Internal conversion of zero to binary and back could yield a result with incorrect precision. (Bug #12911710)
With index condition pushdown enabled,
STRAIGHT_JOIN queries could produce incorrect
(Bug #12822678, Bug #12724899)
Valgrind warnings generated by
operations were fixed.
transformation could yield incorrect results if the outer value
The result of
incorrect for certain numbers.
could return incorrect results.
A memory leak occurred due to failure to clean up after
(Bug #12694872, Bug #14542543)
Several improvements were made to the
library bundled with MySQL distributions, and that is available
for all platforms that MySQL supports except Windows.
Navigation keys did not work for UTF-8 input.
Word navigation and delete operations did not work for UTF-8 input with Cyrillic characters.
Nonlatin characters were corrupted in overwrite mode for UTF-8 input.
Long queries caused the statement history file to become corrupted.
The Alt key caused history operations to fail.
(Bug #12605400, Bug #12613725, Bug #12618092, Bug #12624155, Bug #12617651, Bug #12605388)
SELECT SQL_BUFFER_RESULT query results
included too many rows if a
GROUP BY clause
was optimized away.
decimal_round() could cause a server exit
when processing long numeric strings.
As a result of the fix for this problem, it is now possible to execute statements requiring read locks on the replication log tables at any time, while any statements requiring a write lock on either or both of these tables are disallowed whenever replication is in progress. For more information, see Replication Relay and Status Logs. (Bug #12402875, Bug #60902)
mysqld_safe did not properly check for an already running instance of mysqld. (Bug #11878394)
The client-server protocol now has the client send
authentication data as length-encoded strings so that data
longer than 256 bytes can be sent. This is done using the
value of 1 or 2 and a database having a mixed-case name, calling
a stored function using a fully qualified name including the
database name failed.
(Bug #60347, Bug #11840395)
myisampack could create corrupt
FULLTEXT indexes when compressing tables.
(Bug #53646, Bug #11761180)
For debug builds, an assertion could be raised for
ALTER statements that performed a
RENAME operation. This occurred for storage
engine handlertons that exposed the
(Bug #38028, Bug #11749050)
An assertion designed to detect zero-length sort keys also was raised when the entire key set fit in memory. (Bug #58200, Bug #11765254)
ALTER TABLE that included an
ADD ... AFTER operation to add a new column
after a column that had been modified earlier in the statement
failed to find the existing column.
(Bug #34972, Bug #11748057)
A linking problem prevented the
FEDERATED storage engine plugin
(Bug #40942, Bug #11750417)
When a join operation contained a view, the optimizer sometimes
failed to associate the view's
with the first table or view in a join when it was possible to
do so, resulting in a less efficient query.
(Bug #59696, Bug #11766559)
If index condition pushdown access was chosen and then abandoned, some variables were not cleared, leading to incorrect query results. (Bug #62533)
FEDERATED tables, loss of
connection to the remote table during some insert operations
could cause a server crash.
(Bug #34660, Bug #11747970)
mysql_install_db printed the
--skip-grant-tables server option
--skip-grant in one of its error messages.
(Bug #58534, Bug #11765553)
A query that selected a
GROUP_CONCAT() function result
could return different values depending on whether an
ORDER BY of the function result was present.
(Bug #41090, Bug #11750518)
Subqueries could return incorrect results when materialization was enabled. (Bug #40037, Bug #11749901, Bug #12705660, Bug #12908058)
InnoDB used incorrect identifier quoting
style in an error message that resulted in an error if a user
followed the suggestion in the message.
(Bug #49556, Bug #11757503)
ARCHIVE tables with
NULL columns could cause server crashes or
become corrupt under concurrent load.
(Bug #51252, Bug #11758979)
ZEROFILL values may be
converted to string constants. However,
CASE expressions did not handle
switching data types after the planning stage, leading to
CASE finding a null pointer instead
of its argument.
(Bug #57135, Bug #11764313)
Deadlock could occur when these four things happened at the same
time: 1) An old dump thread was waiting for the binary log to
grow. 2) The slave server that replicates from the old dump
thread tried to reconnect. During reconnection, the new dump
thread tried to kill the old dump thread. 3) A
KILL statement tried to kill the
old dump thread. 4) An
statement caused a binary log rotation.
(Bug #56299, Bug #11763573)
The estimate of space required for
operations could be too high, resulting in inefficient
(Bug #37359, Bug #11748783)
If a plugin was uninstalled, thread local variables for plugin
variables of string type with wth
PLUGIN_VAR_MEMALLOC flag were not freed.
(Bug #56652, Bug #11763882)
An assertion was raised when selecting from a view that selects from a view that used a user-defined function that had been deleted. (Bug #59546, Bug #11766440)
Concurrent access to
ARCHIVE tables could
(Bug #42784, Bug #11751793)
SQL_BIG_RESULT modifier could change the
results for queries that included a
(Bug #53534, Bug #11761078)
The CMake configuration checks did not
properly test whether the C compiler supports the
(Bug #61708, Bug #12711108)
SUM(DISTINCT) incorrectly converted
(Bug #73543, Bug #19427648)
Collation for the
function was determined by the parse time value of the
variable (instead of the runtime value), which could give
unexpected results from prepared statements, triggers, and
(Bug #23637, Bug #11746123)