You can define foreign key constraints on InnoDB
tables. An example: FOREIGN KEY (col1) REFERENCES table2(col2).
You can create > 4 GB datafiles in those
file systems that allow it.
Improved InnoDB monitors, including a new innodb_table_monitor
which allows you to print the contents of the InnoDB internal data
dictionary.
DROP DATABASE will now work also for InnoDB tables.
Accent characters in the default character set
latin1 will be ordered according to the MySQL ordering.<br>
NOTE: if you are using latin1 and have inserted characters
whose code is > 127 to an indexed CHAR column, you should run
CHECK TABLE on your table when you upgrade to
3.23.43, and drop and reimport the table if CHECK TABLE
reports an error!
InnoDB will calculate better table cardinality
estimates.
Change in deadlock resolution:
in .43 a deadlock rolls back only the
SQL statement, in .44 it will roll back the whole transaction.
Deadlock, lock wait timeout, and foreign key
constraint violations (no parent row, child rows exist)
now return native MySQL
error codes 1213, 1205, 1216, 1217, respectively.
A new my.cnf parameter innodb_thread_concurrency
helps in performance tuning in high concurrency environments.
A new my.cnf option innodb_force_recovery will
help you in dumping tables from a corrupted database.
A new my.cnf option innodb_fast_shutdown will
speed up shutdown. Normally InnoDB does a full purge
and an insert buffer merge at shutdown.
Raised maximum key length to 7000 bytes from a
previous limit of 500 bytes.
Fixed a bug in replication of auto-inc columns with multiline inserts.
Fixed a bug when the case of letters changes in an update of an indexed
secondary column.
Fixed a hang when there are > 24 datafiles.
Fixed a crash when MAX(col) is selected from an empty table, and col is a
not the first column in a multi-column index.