Incompatible Change: TIMESTAMP is now returned as a string of type 'YYYY-MM-DD HH:MM:SS' and different timestamp lengths are not supported.

This change was necessary for SQL standards compliance. In a future version, a further change will be made (backward compatible with this change), allowing the timestamp length to indicate the desired number of digits of fractions of a second.

Replication: Replication now works with RAND() and user variables @var.

Allow index type to be specified explicitly for some storage engines via USING type_name syntax in index definition.

Allow DEFAULT(col_name) in expressions; it produces the column's default value.

Added database and real table name (in case of alias) to the MYSQL_FIELD structure.

Renamed SHOW MASTER LOGS statement to SHOW BINARY LOGS.

Unicode (UTF8) support.

Allow one to change mode for ANSI_QUOTES on the fly.

Faster embedded server (new internal communication protocol).

One can specify many temporary directories to be used in a round-robin fashion with: --tmpdir=dirname1:dirname2:dirname3.

New faster client/server protocol that supports prepared statements, bound parameters, and bound result columns, binary transfer of data, warnings.

Aliases are now forced in derived tables, as per standard SQL.

libmysqlclient did not always fetch column default values correctly.

Support for GIS (Geometrical data). See Chapter 16, Spatial Extensions.

The mysql command-line client attempted to interpret quotes within comments. (Bug#539)

REPAIR TABLE and OPTIMIZE TABLE now can be killed. See Section 12.4.6.3, “KILL Syntax”.

Added record_in_range() method to MERGE tables to be able to choose the correct index when there are many to choose from.

New CHARSET() and COLLATION() functions to return the character set and collation of a string.

Added new VARIANCE(expr) function returns the variance of expr

In CREATE TABLE foo (a INT not null primary key) the PRIMARY word is now optional.

CHAR BYTE is an alias for the CHAR BINARY data type.

VARCHARACTER is an alias for VARCHAR.

Added support for UNION in derived tables.

SHOW [COUNT(*)] WARNINGS shows warnings from the last command.

New operators integer MOD integer and integer DIV integer. DIV is now a reserved word.

One can specify a data type for a column in CREATE TABLE ... SELECT by defining the column in the CREATE TABLE part.

CREATE TABLE foo (a TINYINT NOT NULL) SELECT b+1 AS a FROM bar;

expr SOUNDS LIKE expr same as SOUNDEX(expr)=SOUNDEX(expr).

Multi-line queries: You can now issue several queries at once and then read the results in one go.

New CONVERT(... USING ...) syntax for converting string values between character sets.

ALTER DATABASE.

Added old-password command to mysqladmin for changing password but storing it using the old password-hashing format.

In CREATE TABLE the attribute SERIAL is now an alias for BIGINT UNSIGNED NOT NULL AUTO_INCREMENT UNIQUE.

One can specify the different BLOB/TEXT types with the syntax BLOB(length) and TEXT(length). MySQL automatically changes it to one of the internal BLOB/TEXT types.

New more secure client authentication based on 45-byte passwords in the user table. (CVE-2000-0981)

Subqueries: SELECT * from t1 where t1.a=(SELECT t2.b FROM t2).

START SLAVE (STOP SLAVE) no longer returns an error if the slave is started (stopped); it returns a warning instead.

New options --reconnect and --skip-reconnect for the mysql client, to reconnect automatically or not if the connection is lost.

TRUE and FALSE added as alias for 1 and 0, respectively.

DATE/DATETIME checking is now a bit stricter to support the ability to automatically distinguish between date, datetime, and time with microseconds. For example, dates of type YYYYMMDD HHMMDD are no longer supported; you must either have separators between each DATE/TIME part or not at all.

REPAIR TABLE of MyISAM tables now uses less temporary disk space when sorting char columns.

Derived tables:

SELECT a.col1, b.col2
       FROM (SELECT MAX(col1) AS col1 FROM root_table) a,
       other_table b
       WHERE a.col1=b.col1;

Added --compatible option to mysqldump for producing output that is compatible with other database systems or with older MySQL servers.

DROP TEMPORARY TABLE now drops only temporary tables and doesn't end transactions.

SELECT .. LIMIT 0 did not return the proper row count for SQL_CALC_FOUND_ROWS.

One can create a table from the existing table using CREATE [TEMPORARY] TABLE [IF NOT EXISTS] table (LIKE table). The table can be either normal or temporary.

One can add a comment per column in CREATE TABLE.

SERIAL DEFAULT VALUE added as an alias for AUTO_INCREMENT.

New function IS_USED_LOCK() for determining the connection identifier of the client that holds a given advisory lock.

SELECT ... FROM DUAL is an alias for SELECT .... (To be compatible with some other database systems).

EXPLAIN SELECT now can be killed. See Section 12.4.6.3, “KILL Syntax”.

Server side help for all MySQL functions. One can now type help week in the mysql client and get help for the week() function.

Allow empty index lists to be specified for USE INDEX, IGNORE INDEX, and FORCE INDEX.

SHOW FULL COLUMNS FROM tbl_name shows column comments.

Character sets to be defined per column, table and database.

Added new mysql_get_server_version() C API client function.

New CRC32() function to compute cyclic redundancy check value.

BTREE index on MEMORY (HEAP) tables.

If one creates a too long CHAR/VARCHAR it is now automatically changed to TEXT or BLOB; One get a warning in this case.

On Windows, we are now using shared memory to communicate between server and client when they are running on the same machine and you are connecting to localhost.

SLAVE START and SLAVE STOP are no longer accepted by the query parser; use START SLAVE and STOP SLAVE instead.

The --opt option for mysqldump now is enabled by default, as are all the options implied by --opt.