Recursion in stored routines is now disabled because it was crashing the server. (Bug #11394)

An attempt to create a TIMESTAMP column with a display width (for example, TIMESTAMP(6)) now results in a warning. Display widths have not been supported for TIMESTAMP since MySQL 4.1. (Bug #10466)

InnoDB: When creating or extending an InnoDB data file, at most one megabyte at a time is allocated for initializing the file. Previously, InnoDB allocated and initialized 1 or 8 megabytes of memory, even if only a few 16-kilobyte pages were to be written. This improves the performance of CREATE TABLE in innodb_file_per_table mode.

InnoDB: Various optimizations. Removed unreachable debug code from nondebug builds. Added hints for the branch predictor in gcc. Made assertions occupy less space.

The handling of BIT columns has been improved, and should now be much more reliable in a number of cases. (Bug #11572, Bug #11091, Bug #10617)

mysql_real_escape_string() API function now respects NO_BACKSLASH_ESCAPES SQL mode. (Bug #10214)

InnoDB: Make innodb_thread_concurrency = 20 by default. Bypass the concurrency checking if the setting is greater than or equal to 20.

InnoDB: Made CHECK TABLE killable. (Bug #9730)

MySQL Cluster: When trying to open a table that could not be discovered or unpacked, the cluster returned error codes which the MySQL server falsely interpreted as operating system errors. (Bug #10365)

The ENCRYPT() and SUBSTRING_INDEX() functions would cause errors when used with a VIEW. (Bug #7024)

Optimizer performed range check when comparing unsigned integers to negative constants, could cause errors. (Bug #11185)

A compression algorithm issue caused myisampackto fail for very large data sets (where the total size of all records in a single column was on the order of 3 GB or more) on 64-bit platforms. (A fix for other platforms was made in MySQL 5.0.6.) (Bug #8321)

SHOW CREATE VIEW did not take the ANSI SQL mode into account when quoting identifiers. (Bug #6903)

mysqldump could crash for illegal or nonexistent table names. (Bug #9358)

The mysql_config script did not handle symbolic linking properly. (Bug #10986)

mysqldump --xml did not format NULL column values correctly. (Bug #9657)

When used in joins, SUBSTRING() failed to truncate to zero those string values that could not be converted to numbers. (Bug #10124)

DES_ENCRYPT() and DES_DECRYPT() require SSL support to be enabled, but were not checking for it. Checking for incorrect arguments or resource exhaustion was also improved for these functions. (Bug #10589)

Signed BIGINT would not accept -9223372036854775808 as a DEFAULT value. (Bug #11215)

Combining cursors and subqueries could cause server crash or memory leaks. (Bug #10736)

mysqldump failed when reloading a view if the view was defined in terms of a different view that had not yet been reloaded. mysqldump now creates a dummy table to handle this case. (Bug #10927)

Temporary tables were created in the data directory instead of tmpdir. (Bug #11440)

Instances of the VAR_SAMP() function in view definitions were converted to VARIANCE(). This is incorrect because VARIANCE() is the same as VAR_POP(), not VAR_SAMP(). (Bug #10651)

Wrong comparison method used in VIEW when relaxed date syntax used (for example, 2005.06.10). (Bug #11325)

For MEMORY tables, it was possible for updates to be performed using outdated key statistics when the updates involved only very small changes in a very few rows. This resulted in the random failures of queries such as UPDATE t SET col = col + 1 WHERE col_key = 2; where the same query with no WHERE clause would succeed. (Bug #10178)

The --master-data option for mysqldump resulted in no error if the binary log was not enabled. Now an error occurs unless the --force option is given. (Bug #11678)

Views did not use indexes on all appropriate queries. (Bug #10031)

Manually inserting a row with host='' into mysql.tables_priv and performing a FLUSH PRIVILEGES would cause the server to crash. (Bug #11330)

MySQL would not compile correctly on QNX due to missing rint() function. (Bug #11544)

Incorrect results when using GROUP BY ... WITH ROLLUP on a VIEW. (Bug #11639)

When a table had a primary key containing a BLOB column, creation of another index failed with the error BLOB/TEXT column used in key specification without keylength, even when the new index did not contain a BLOB column. (Bug #11657)

In strict mode, an INSERT into a view that did not include a value for a NOT NULL column but that did include a WHERE test on the same column would succeed, This happened even though the INSERT should have been prevented due to the failure to supply a value for the NOT NULL column. (Bug #6443)

A SELECT DISTINCT col_name would work correctly with a MyISAM table only when there was an index on col_name. (Bug #11484)

If a prepared statement cursor is opened but not completely fetched, attempting to open a cursor for a second prepared statement will fail. (Bug #10794)

Closing a cursor that was already closed would cause MySQL to hang. (Bug #9814)

A cursor using a query with a filter on a DATE or DATETIME column would cause the server to crash server after the data was fetched. (Bug #11172)

The --no-data option for mysqldump was being ignored if table names were given after the database name. (Bug #9558)

Clients would hang following some errors with stored procedures. (Bug #9503)

Using CONCAT_WS() on a column set NOT NULL caused incorrect results when used in a LEFT JOIN. (Bug #11469)

Running a CHECK TABLES on multiple views crashed the server. (Bug #11337)

The server would lose table-level CREATE VIEW and SHOW VIEW privileges following a FLUSH PRIVILEGES or server restart. (Bug #9795)