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), permitting 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.

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

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

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.

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

BTREE index on MEMORY (HEAP) tables.

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

Added new mysql_get_server_version() C API client function.

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

SHOW FULL COLUMNS FROM tbl_name shows column comments.

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

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

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

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

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

SERIAL DEFAULT VALUE added as an alias for AUTO_INCREMENT.

One can add a comment per column in CREATE TABLE.

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.

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

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

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

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;

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

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.

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

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

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

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

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

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.

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

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

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

ALTER DATABASE.

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

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

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

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;

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

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

Added support for UNION in derived tables.

VARCHARACTER is an alias for VARCHAR.

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

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

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

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

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

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

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

libmysqlclient did not always fetch column default values correctly.

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

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

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

Faster embedded server (new internal communication protocol).

Permit the ANSI_QUOTES SQL mode to be changed on the fly.

Unicode (UTF8) support.

Renamed SHOW MASTER LOGS statement to SHOW BINARY LOGS.

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

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

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