Fixed range optimiser bug: SELECT * FROM table_name
WHERE key_part1 >= const AND (key_part2 = const OR
key_part2 = const)
. The bug was that some rows
could be duplicated in the result.
Running myisamchk
without
-a
updated the index distribution
incorrectly.
SET SQL_LOW_PRIORITY_UPDATES=1
was
causing a parse error.
You can now update index columns that are used in the
WHERE
clause. UPDATE tbl_name
SET KEY=KEY+1 WHERE KEY > 100
Date handling should now be a bit faster.
Added handling of fuzzy dates (dates where day or month is
0), such as '1999-01-00'
.
Fixed optimization of SELECT ... WHERE
key_part1=const1 AND key_part_2=const2 AND key_part1=const4
AND key_part2=const4
; indextype should be
range
instead of ref
.
Fixed egcs
1.1.2 optimiser bug (when
using BLOB
values) on Linux Alpha.
Fixed problem with LOCK TABLES
combined
with DELETE FROM table
.
MyISAM
tables now allow keys on
NULL
and BLOB/TEXT
columns.
The following join is now much faster: SELECT ...
FROM t1 LEFT JOIN t2 ON ... WHERE t2.not_null_column IS
NULL
.
ORDER BY
and GROUP BY
can be done on functions.
Changed handling of 'const_item' to allow handling of
ORDER BY RAND()
.
Indexes are now used for WHERE key_column =
function
.
Indexes are now used for WHERE key_column =
col_name
even if the columns are not identically
packed.
Indexes are now used for WHERE col_name IS
NULL
.
Changed heap tables to be stored in low_byte_first order (to
make it easy to convert to MyISAM
tables)
Automatic change of HEAP
temporary tables
to MyISAM
tables in case of ``table is
full'' errors.
Added --init-file=file_name
option to
mysqld
.
Added COUNT(DISTINCT value, [value,
...])
.
CREATE TEMPORARY TABLE
now creates a
temporary table, in its own namespace, that is automatically
deleted if connection is dropped.
New reserved words (required for CASE
):
CASE, THEN, WHEN, ELSE and END
.
New functions EXPORT_SET()
and
MD5()
.
Support for the GB2312 Chinese character set.
This is a translation of the MySQL Reference Manual that can be found at dev.mysql.com. The original Reference Manual is in English, and this translation is not necessarily as up to date as the English version.