Fixed Rows_examined count in slow query log.
Fixed bug when using a reference to an AVG() column in HAVING.
Fixed that date functions that require correct dates, like DAYOFYEAR(column), will return NULL for 0000-00-00 dates.
Fixed bug in const-propagation when comparing columns of different types. (SELECT * FROM date_col="2001-01-01" and date_col=time_col)
Fixed bug that caused error message Can't write, because of unique constraint with some GROUP BY queries.
Fixed problem with sjis character strings used within quoted table names.
Fixed core dump when using CREATE ... FULLTEXT keys with other storage engines than MyISAM.
Don't use signal() on Windows because this appears to not be 100% reliable.
Fixed bug when doing WHERE col_name=NULL on an indexed column that had NULL values.
Fixed bug when doing LEFT JOIN ... ON (col_name = constant) WHERE col_name = constant.
When using replications, aborted queries that contained % could cause a core dump.
TCP_NODELAY was not used on some systems. (Speed problem.)
Applied portability fixes for OS/2. (Patch by Yuri Dario.)
The following changes are for InnoDB tables:
Add missing InnoDB variables to SHOW VARIABLES.
Foreign keys checking is now done for InnoDB tables.
DROP DATABASE now works also for InnoDB tables.
InnoDB now supports datafiles and raw disk partitions bigger than 4 GB on those operating systems that have big files.
InnoDB calculates better table cardinality estimates for the MySQL optimizer.
Accent characters in the default character set latin1 are ordered according to the MySQL ordering.
Note: if you are using latin1 and have inserted characters whose code is greater than 127 into an indexed CHAR column, you should run CHECK TABLE on your table when you upgrade to 3.23.44, and drop and reimport the table if CHECK TABLE reports an error!
A new my.cnf parameter, innodb_thread_concurrency, helps in performance tuning in heavily concurrent environments.
A new my.cnf parameter, innodb_fast_shutdown, speeds up server shutdown.
A new my.cnf parameter, innodb_force_recovery, helps to save your data in case the disk image of the database becomes corrupt.
innodb_monitor has been improved and a new innodb_table_monitor added.
Increased maximum key length from 500 to 7000 bytes.
Fixed a bug in replication of AUTO_INCREMENT columns with multiple-line 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 not the first column in a multi-column index.
Fixed a bug in purge which could cause crashes.