Improved the optimizer to be able to use indexes for expressions of the form indexed_col NOT IN (val1, val2, ...) and indexed_col NOT BETWEEN val1 AND val2. (Bug#10561)

The table, type, and rows columns of EXPLAIN output can now be NULL. This is required for using EXPLAIN on SELECT queries that use no tables, such as EXPLAIN SELECT 1). (Bug#9899)

All characters occurring on the same line following the DELIMITER keyword will be set as delimiter. For example, DELIMITER :; will set :; as the delimiter. This behavior is now consistent between MySQL 5.1 and MySQL 5.0. (Bug#9879)

Added mysql_set_character_set() C API function for setting the default character set of the current connection. This allows clients to affect the character set used by mysql_real_escape_string(). (Bug#8317)

The --delayed-insert option for mysqldump was disabled to avoid causing problems with storage engines that do not support INSERT DELAYED. (Bug#7815)

Placeholders now can be used for LIMIT in prepared statements. (Bug#7306)

InnoDB: In stored procedures and functions, InnoDB no longer takes full explicit table locks for every involved table. Only `intention' locks are taken, similar to those in the execution of an ordinary SQL statement. This greatly reduces the number of deadlocks.

SHOW BINARY LOGS now displays a File_size column that indicates the size of each file.

Security improvement: Applied a patch to fix a UDF library-loading vulnerability that could result in a buffer overflow and code execution. (CVE-2005-2558)

Removed WinMySQLAdmin from the source distribution and from the “No Installer” Windows distribution (it had already been removed from the “With Installer” distribution before).

The behavior of the Last_query_cost system variable has been changed. The default value is now 0 (rather than -1) and it now has session-level scope (rather than being global). See Section 5.1.5, “Status Variables”, for additional information.

Removed mysqlshutdown.exe and mysqlwatch.exe from the Windows “No Installer” distribution (they had already been removed from the “With Installer” distribution before). Removed those programs from the source distribution.

MySQL would pass an incorrect key length to storage engines for MIN(). This could cause spurious warnings such as InnoDB: Warning: using a partial-field key prefix in search to appear in the .err log. (Bug#13218, Bug#11039)

Fixed a portability problem for compiling on Windows with Visual Studio 6. (Bug#11153)

Corrected a problem where an incorrect data type was returned in the result set metadata when using a prepared SELECT DISTINCT statement to select from a view. (Bug#11111)

Fixed a server crash resulting from an attempt to allocate too much memory when GROUP BY blob_col and COUNT(DISTINCT) were used. (Bug#11088)

Multiple-row REPLACE could fail on a duplicate-key error when having one AUTO_INCREMENT key and one unique key. (Bug#11080)

InnoDB: Fixed a duplicate key error that occurred with REPLACE in a table with an AUTO-INC column. (Bug#11005)

Fixed a failure of WITH ROLLUP to sum values properly. (Bug#10982)

Security update: A user with limited privileges could obtain information about the privileges of other users by querying objects in the INFORMATION_SCHEMA database for which that user did not have the requisite privileges. (Bug#10964)

The value returned by the FIELD() function was incorrect when its parameter list contained one or more instances of NULL. (Bug#10944)

Failure of a BEFORE trigger did not prevent the triggering statement from performing its operation on the row for which the trigger error occurred. Now the triggering statement fails as described in Section 20.3, “Using Triggers”. (Bug#10902)

The FEDERATED storage engine properly handled outer joins, but not inner joins. (Bug#10848)

Executing LOAD INDEX INTO CACHE for a table while other threads where selecting from the table caused a deadlock. (Bug#10602)

The TIME_FORMAT() function returned incorrect results with some format specifiers. See Section 11.6, “Date and Time Functions”. (Bug#10590)

The LAST_DAY() failed to return NULL when supplied with an invalid argument. See Section 11.6, “Date and Time Functions”. (Bug#10568)

A problem with the my_global.h file caused compilation of MySQL to fail on single-processor Linux systems running 2.6 kernels. (Bug#10364)

Corrected inappropriate error messages that were displayed when attempting to set the read-only warning_count and error_count system variables. (Bug#10339)

Fixed bug in the MySQL Instance manager that caused the version to always be unknown when SHOW INSTANCE STATUS was issued. (Bug#10229)

Fixed a server crash resulting from CREATE TABLE ... SELECT that selected from a table being altered by ALTER TABLE. (Bug#10224)

Fixed a server crash resulting from invalid string pointer when inserting into the mysql.host table. (Bug#10181)

Consistently report INFORMATION_SCHEMA table names in uppercase in SHOW TABLE STATUS output. (Bug#10059)

Fixed a server crash resulting from accessing InnoDB tables within stored functions. This is handled by prohibiting statements that do an implicit or explicit commit or rollback within stored functions or triggers. (Bug#10015)

Issuing a write lock for a table from one client prevented other clients from accessing the table's metadata. For example, if one client issued a LOCK TABLES mydb.mytable WRITE, then a second client attempting to execute a USE mydb; would hang. (Bug#9998)

Dropping stored routines when the MySQL server had been started with --skip-grant-tables generated extraneous warnings. (Bug#9993)

The mysql_next_result() function could hang if you were executing many statements in a mysql_real_query() call and one of those statements raised an error. (Bug#9992)

The functions COALESCE(), IF(), and IFNULL() performed incorrect conversions of their arguments. (Bug#9939)

Fixed a problem with returning an incorrect result from a view that selected a COALESCE() expression from the result of an outer join. (Bug#9938)

InnoDB: Do very fast shutdown only if innodb_fast_shutdown=2, but wait for threads to exit and release allocated memory if innodb_fast_shutdown=1. Starting with MySQL/InnoDB 5.0.5, InnoDB would do brutal shutdown also when innodb_fast_shutdown=1. (Bug#9673)

Using ORDER BY to sort the results of an IF() that contained a FROM_UNIXTIME() expression returned incorrect results due to integer overflow. (Bug#9669)

On Windows, with lower_case_table_names set to 2, using ALTER TABLE to alter a MEMORY or InnoDB table that had a mixed-case name also improperly changed the name to lowercase. (Bug#9660)

The combination of COUNT(), DISTINCT, and CONCAT() sometimes triggered a memory deallocation bug on Windows resulting in a server crash. (Bug#9593)

INSERT BEFORE triggers were not being activated for implicit inserts (LOAD DATA). (Bug#8755)

The ucs2_turkish_ci collation failed with upper('i'). UPPER/LOWER now can return a string with different length. (Bug#8610)

The server timed out SSL connections too quickly on Windows. (Bug#8572)

If a stored function contained a FLUSH statement, the function crashed when invoked. FLUSH now is disallowed within stored functions. (Bug#8409)

OPTIMIZE run on an InnoDB table did not return a Table is full error if there was insufficient room in the tablespace. (Bug#8135)

Fixed a problem causing an incorrect result for columns that include an aggregate function as part of an expression when WITH ROLLUP is added to GROUP BY. (Bug#7914)

Queries with ROLLUP returned wrong results for expressions containingGROUP BY columns. (Bug#7894)

Fixed a server crash resulting from the second invocation of a stored procedure that selected from a view defined as a join that used ON in the join conditions. (Bug#6866)

INSERT BEFORE triggers were not being activated for INSERT ... SELECT statements. (Bug#6812)

Fixed a server crash for INSERT or UPDATE when the WHERE clause contained a correlated subquery that referred to a column of the table being modified. (Bug#6384)

MySQL was adding a DEFAULT clause to ENUM columns that included no explicit DEFAULT and were defined as NOT NULL. (This is supposed to happen only for columns that are NULL.) (Bug#6267)

Using ALTER TABLE for a table that had a trigger caused a crash when executing a statement that activated the trigger, and also a crash later with USE db_name for the database containing the table. (Bug#5894)

Triggers with dropped functions caused crashes. (Bug#5893)

Triggers were not being activated for multiple-table UPDATE or DELETE statements. (Bug#5860)

The incorrect sequence of statements HANDLER tbl_name READ index_name NEXT without a preceding HANDLER tbl_name READ index_name = (value_list) for an InnoDB table resulted in a server crash rather than an error. (Bug#5373)

Multiple-table DELETE did always delete on the fly from the first table that was to be deleted from. In some cases, when using many tables and it was necessary to access the same row twice in the first table, we could miss some rows-to-be-deleted from other tables. This is now fixed.