MySQL Cluster: Added support for a [mysql_cluster] section to the my.cnf file for configuration settings specific to MySQL Cluster. The ndb-connectstring variable was moved here.

Replication: mysqldump --single-transaction --master-data is now able to take an online (nonblocking) dump of InnoDB and report the corresponding binary log coordinates, which makes a backup suitable for point-in-time recovery, roll-forward or replication slave creation. See Section 4.5.4, “mysqldump — A Database Backup Program”.

A connection doing a rollback now displays "Rolling back" in the State column of SHOW PROCESSLIST.

Added --lock-all-tables to mysqldump to lock all tables by acquiring a global read lock.

In the normal log MySQL now prints the log position for Binlog Dump requests.

mysqlbinlog now prints an informative commented line (thread id, timestamp, server id, and so forth) before each LOAD DATA INFILE, like it does for other queries; unless --short-form is used.

Added --disable-log-bin option to mysqlbinlog. Using this option you can disable binary logging for the statements produced by mysqlbinlog. That is, mysqlbinlog --disable-log-bin <file_name> | mysql won't write any statements to the MySQL server binary log.

Automatic character set conversion formerly was done for operations that mix a column and a string such as assigning a string to a column, when this was possible without loss of information. Automatic conversion for operations that mix columns and strings has been expanded to cover many functions (such as CONCAT()) and assignment operators. This reduces the frequency of Illegal mix of collations errors.

For ALTER DATABASE, the database name now can be omitted to apply the change to the default database.

Added WITH CONSISTENT SNAPSHOT clause to START TRANSACTION to begin a transaction with a consistent read.

The statements CREATE TABLE, TRUNCATE TABLE, DROP DATABASE, and CREATE DATABASE cause an implicit commit.

The --master-data option for mysqldump now takes an optional argument of 1 or 2 to produce a noncommented or commented CHANGE MASTER TO statement. The default is 1 for backward compatibility.

Added --hex-blob option to mysqldump for dumping binary string columns using hexadecimal notation.

Added --order-by-primary to mysqldump, to sort each table's data in a dump file. This may be useful when dumping a MyISAM table which will be loaded into an InnoDB table. Dumping a MyISAM table with this option is considerably slower than without.

InnoDB: Commit after every 10,000 copied rows when executing ALTER TABLE. This makes it much faster to recover from an aborted ALTER TABLE or OPTIMIZE TABLE.

FULLTEXT index block size is changed to be 1024 instead of 2048.

InnoDB: Do not periodically write SHOW INNODB STATUS information to a temporary file unless the configuration option innodb_status_file = 1 is set.

Added mysql_hex_string() C API function that hex-encodes a string.

Replication: Changed semantics of CREATE/ALTER/DROP DATABASE statements so that replication of CREATE DATABASE is possible when using --binlog-do-db and --binlog-ignore-db. (Bug#6391)

Replication: LOAD DATA INFILE now works with option replicate-rewrite-db. (Bug#6353)

Replication: InnoDB: If one used INSERT IGNORE to insert several rows at a time, and the first inserts were ignored because of a duplicate key collision, then InnoDB in a replication slave assigned AUTO_INCREMENT values 1 bigger than in the master. This broke the MySQL replication. (Bug#6287)

Replication: OPTIMIZE TABLE, REPAIR TABLE, and ANALYZE TABLE are now replicated without any error code in the binary log. (Bug#5551)

Using a modified client library, a malicious user could take advantage of an issue in MySQL authentication code to crash the server with specially crafted packets. (Bug#7187)

Using the string function LEFT as part of the expression used as GROUP BY column caused the server to crash. (Bug#7101)

InnoDB: Refuse to open new-style tables created with MySQL 5.0.3 or later. (Bug#7089)

A reference to a column by name from a WHERE subquery to an outer query, with use of a temporary table by the outer query. (Bug#7079)

Insufficient privilege checks were made for SHOW CREATE TABLE. (Bug#7043)

mysql_stmt_data_seek(stmt,0) now rewinds a counter and enables buffered rows to be re-fetched on the client side. (Bug#6996)

Some complex queries did not work correctly with subqueries. (Bug#6841, Bug#6406)

InnoDB: Do not intentionally crash mysqld if the buffer pool is exhausted by the lock table; return error 1206 instead. Do not intentionally crash mysqld if we cannot allocate the memory for the InnoDB buffer pool. (Bug#6817, Bug#6827)

NULL were not handled caorrectly in cases of empty results in subqueries. (Bug#6806)

A spurious "duplicate key" error resulted from executing a REPLACE or INSERT ... ON DUPLICATE KEY UPDATE statement performing a multiple-row insert on a table having unique and full-text indexes. (Bug#6784)

MySQL required explicit privileges on system time zone description tables for implicit access to them (that is, if one set the time_zone variable or used the CONVERT_TZ() function) in cases where some table-level or column-level privileges already existed. (Bug#6765)

A spurious Record has changed since last read in table error could be raised by some queries on HEAP tables containing only one row. (Bug#6748)

InnoDB: innodb_locks_unsafe_for_binlog still uses next-key locking, which is unnecessary next-key. Such locks are now removed when the innodb_locks_unsafe_for_binlog option is enabled. (Bug#6747)

A sequence of BEGIN (or SET autocommit = 0), FLUSH TABLES WITH READ LOCK, transactional update, COMMIT, FLUSH TABLES WITH READ LOCK could hang the connection forever and possibly the MySQL server itself. This happened for example when running the innobackup script several times. (Bug#6732)

Prevent adding CREATE TABLE .. SELECT query to the binary log when the insertion of new records partially failed. (Bug#6682)

mysqlbinlog did not print SET PSEUDO_THREAD_ID statements in front of LOAD DATA INFILE statements inserting into temporary tables, thus causing potential problems when rolling forward these statements after restoring a backup. (Bug#6671)

Backported a fix for the full-text interface from MySQL 5.0. (Bug#6523)

If a connection was interrupted by a network error and did a rollback, the network error code got stored into the BEGIN and ROLLBACK binary log events; that caused superfluous slave stops. (Bug#6522)

Some internal structures were not initialized correctly prior to first execution. (Bug#6517)

Execution of subqueries in SET and DO statements caused wrong results to be returned from subsequent queries. (Bug#6462)

A multiple-table DELETE could cause MySQL to crash when using InnoDB tables. (Bug#6378, Bug#5837)

InnoDB: Made the foreign key parser better aware of quotes. (Bug#6340)

INSERT ... SELECT no longer reports spurious "column truncated" warnings (Bug#6284)

A rare memory corruption problem could cause MATCH ... AGAINST on columns using multi-byte character sets to crash the server. (Bug#6269)

The server accepted datetime values with an invalid year part. The server now also performs the same checks for datetime values passed through MYSQL_TIME structures as for datetime values passed as strings. (Bug#6266)

INSERT on a table with FULLTEXT indexes, could under rare circumstances result in a corrupted table if words of different lengths could be considered equal. This is possible in some collations such as utf8_general_ci and latin1_german2_ci. (Bug#6265)

NULL was not always processed correctly in subqueries using ALL or SOME. (Bug#6247)

Starting and stopping the slave thread (only) could in some circumstance cause the server to crash. (Bug#6148)

If STMT_ATTR_UPDATE_MAX_LENGTH is set for a prepared statement, mysql_stmt_store_result() updates field->max_length for numeric columns as well. (Bug#6096)

If a connection had an open transaction but had done no updates to transactional tables (for example if had just done a SELECT FOR UPDATE then executed a nontransactional update, that update automatically committed the transaction (thus releasing InnoDB's row-level locks etc). (Bug#5714)

InnoDB: FOREIGN KEY constraints treated table and database names as case-insensitive, so that RENAME TABLE t TO T would hang in an endless loop if t had a foreign key constraint defined on it. The server would also hang if one tried using an ALTER TABLE or RENAME TABLE statement to create a foreign key constraint name that collided with existing one. (Bug#3478)

A call to mysql_stmt_store_result() occurred without a preceding call to mysql_stmt_bind_result() caused the server to crash.

CREATE TABLE created_table didn't signal when table was created. This could cause a DROP TABLE created_table in another thread to wait "forever".

Prepared statements now handle ZEROFILL when converting integer to string.

GROUP_CONCAT(...ORDER BY) when used with prepared statements gave wrong sorting order.

The server was interpreting CHAR BINARY and VARCHAR BINARY columns from 4.0 tables as having the BINARY and VARBINARY data types. Now they are interpreted as CHAR and VARCHAR columns that have the binary collation of the column's character set. (This is the same way that CHAR BINARY and VARCHAR BINARY are handled for new tables created in 4.1.)

InnoDB: Do not call rewind() when displaying SHOW INNODB STATUS information on stderr.

A prepared statement using SELECT * FROM t1 NATURAL JOIN t2... could cause the server to crash.

A prepared statement using a subquery could cause the server to crash.

A prepared statement using SELECT ... PROCEDURE could cause the server to crash.

mysqld_safe was in many cases ignoring any --no-defaults, --defaults-file, or --defaults-extra-file arguments. Those arguments are now honored, and this may change what options are passed to mysqld in some installations.

Improved performance of identifier comparisons (if many tables or columns are specified).

InnoDB: Let the InnoDB FOREIGN KEY parser remove the latin1 character 0xA0 from the end of an unquoted identifier. The EMS MySQL Manager in ALTER TABLE adds that character after a table name, which caused error 121 when we tried to add a new constraint.

InnoDB: innodb_data_file_path was not handled correctly in some cases. This bug was introduced in MySQL 4.1.1.

Server warnings now are reset when you execute a prepared statement.