Rows_examined
count in slow query log.
AVG()
column in HAVING
.
DAYOFYEAR(column)
, will return NULL
for 0000-00-00
dates.
SELECT * FROM date_col="2001-01-01" and date_col=time_col
)
Can't write, because of unique
constraint
with some GROUP BY
queries.
sjis
character strings used within quoted table
names.
CREATE ... FULLTEXT
keys with other
storage engines than MyISAM
.
signal()
on Windows because this appears to not be
100% reliable.
WHERE col_name=NULL
on an indexed column
that had NULL
values.
LEFT JOIN ... ON (col_name = constant) WHERE col_name = constant
.
%
could cause
a core dump.
TCP_NODELAY
was not used on some systems. (Speed problem.)
The following changes are for InnoDB
tables:
InnoDB
variables to SHOW VARIABLES
.
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 optimiser.
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!
innodb_thread_concurrency
, helps in
performance tuning in heavily concurrent environments.
innodb_fast_shutdown
, speeds up
server shutdown.
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.
AUTO_INCREMENT
columns with
multiple-line inserts.
MAX(col)
is selected from an empty table, and
col
is not the first column in a multi-column index.