InnoDB now supports
DROP FOREIGN KEY. You have to use
SHOW CREATE TABLE to find the
internally generated foreign key ID when you want to drop a
SHOW INNODB STATUS now prints
detailed information of the latest detected
UNIQUE KEY errors. If you
do not understand why
InnoDB gives the
error 150 from a
you can use this statement to study the reason.
ANALYZE TABLE now works also
InnoDB type tables. It makes eight
random dives to each of the index trees and updates index
cardinality estimates accordingly. Note that because these are
only estimates, repeated runs of
TABLE may produce different numbers. MySQL uses
index cardinality estimates only in join optimization. If some
join is not optimized in the right way, you may try using
InnoDB group commit capability now works
also when MySQL binary logging is switched on. There have to
be > 2 client threads for the group commit to become
Changed the default value of
from 0 to 1. If you have not specified it explicitly in your
my.cnf, and your application runs much
slower with this new release, it is because the value 1 causes
a log flush to disk at each transaction commit.
Added a new global settable MySQL system variable
It is an integer in the range 0 - 100. The default is 90. The
main thread in
InnoDB tries to flush pages
from the buffer pool so that at most this many percents are
not yet flushed at any time.
innodb_force_recovery=6, do not let
InnoDB do repair of corrupt pages based on
the doublewrite buffer.
InnoDB startup now happens faster because
it does not set the memory in the buffer pool to zero.
Fixed a bug: The
InnoDB parser for
FOREIGN KEY definitions was confused by the
keywords 'foreign key' inside MySQL comments.
Fixed a bug: If you dropped a table to which there was a
FOREIGN KEY reference, and later created
the same table with nonmatching data types,
InnoDB could assert in
dict0load.c, in function
Fixed a bug:
GROUP BY and
DISTINCT could treat
NULL values as not equal. MySQL also failed
to do the next-key locking in the case of an empty index
Fixed a bug: Do not commit the current transaction when a
MyISAM table is updated; this also makes
CREATE TABLE not to commit an
InnoDB transaction, even when binary
logging is enabled.
Fixed a bug: We did not allow
ON DELETE SET
NULL to modify the same table where the delete was
made; we can allow it because that cannot produce infinite
loops in cascaded operations.
Fixed a bug: Enable
HANDLER PREV and
NEXT also after positioning the cursor with
a unique search on the primary key.
Fixed a bug:
InnoDB forgot to call
pthread_mutex_destroy() when a table was
dropped. That could cause memory leakage on FreeBSD and other
non-Linux Unix systems.