Functionality added or changed:
Incompatible Change: MySQL Cluster:
The LockPagesInMainMemory configuration
parameter has changed its type and possible values. For more
information, see
LockPagesInMainMemory.
The values true and
false are no longer accepted for this
parameter. If you were using this parameter and had it set to
false in a previous release, you must
change it to 0. If you had this parameter
set to true, you should instead use
1 to obtain the same behavior as
previously, or 2 to take advantage of new
functionality introduced with this release, as described in
the section cited above.
Incompatible Change:
InnoDB rolls back only the last statement on
a transaction timeout. A new option,
--innodb_rollback_on_timeout, causes
InnoDB to abort and roll back the entire
transaction if a transaction timeout occurs (the same behavior
as in MySQL 5.0.13 and earlier).
(Bug#24200)
Incompatible Change:
Previously, the DATE_FORMAT()
function returned a binary string. Now it returns a string with
a character set and collation given by
character_set_connection and
collation_connection so that it can return
month and weekday names containing non-ASCII characters.
(Bug#22646)
Incompatible Change:
The following conditions apply to enabling the
read_only system variable:
If you attempt to enable read_only while
you have any explicit locks (acquired with LOCK
TABLES or have a pending transaction, an error
will occur.
If other clients hold explicit table locks or have pending
transactions, the attempt to enable
read_only blocks until the locks are
released and the transactions end. While the attempt to
enable read_only is pending, requests by
other clients for table locks or to begin transactions also
block until read_only has been set.
read_only can be enabled while you hold a
global read lock (acquired with FLUSH TABLES WITH
READ LOCK) because that does not involve table
locks.
Previously, the attempt to enable read_only
would return immediately even if explicit locks or transactions
were pending, so some data changes could occur for statements
executing in the server at the same time.
(Bug#22009, Bug#11733)
Bugs fixed:
Incompatible Change:
For ENUM columns that had enumeration values
containing commas, the commas were mapped to
0xff internally. However, this rendered the
commas indistinguishable from true 0xff
characters in the values. This no longer occurs. However, the
fix requires that you dump and reload any tables that have
ENUM columns containing any true
0xff values. Dump the tables using
mysqldump with the current server before
upgrading from a version of MySQL 5.1 older than 5.1.15 to
version 5.1.15 or newer.
(Bug#24660)
