CHAR BYTE is an alias for the BINARY data type. (Previously, it was an alias for CHAR BINARY.)

Warning: Incompatible change: Handling of the FLOAT and DOUBLE floating-point data types is more strict to follow standard SQL. For example, a data type of FLOAT(3,1) stores a maximum value of 99.9. Previously, the server allowed larger numbers to be stored. That is, it stored a value such as 100.0 as 100.0. Now the server clips 100.0 to the maximum allowable value of 99.9. If you have tables that were created before MySQL 4.1.2 and that contain floating-point data not strictly legal for the column type, you should alter the data types of those columns. For example:

ALTER TABLE tbl_name MODIFY col_name FLOAT(4,1);

Warning: Incompatible change: String comparison now works according to the SQL standard. Because we have that 'a' = 'a ' then from it must follow that 'a' > 'a\t'. (The latter was not the case before MySQL 4.1.2.) To implement it, we had to change how storage engines compare strings internally. As a side effect, if you have a table where a CHAR or VARCHAR column in some row has a value with the last character less than ASCII(32), you have to repair this table. CHECK TABLES tells you if this problem exists. (Bug#3152)

Added support for DEFAULT CURRENT_TIMESTAMP and for ON UPDATE CURRENT_TIMESTAMP specifications for TIMESTAMP columns. Now you can explicitly say that a TIMESTAMP column should be set automatically to the current timestamp for INSERT and/or UPDATE statements, or even prevent the column from updating automatically. Only one column with such an auto-set feature per table is supported. TIMESTAMP columns created with earlier versions of MySQL behave as before. Behavior of TIMESTAMP columns that were created without explicit specification of default/on as earlier depends on its position in table: If it is the first TIMESTAMP column, it be treated as having been specified as TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP. In other cases, it would be treated as a TIMESTAMP DEFAULT 0 column. NOW is supported as an alias for CURRENT_TIMESTAMP. Warning: Incompatible change: Unlike in previous versions, explicit specification of default values for TIMESTAMP column is never ignored and turns off the auto-set feature (unless you have CURRENT_TIMESTAMP as the default).

Warning: Incompatible change: Renamed prepared statements C API functions:

Now all functions that operate with a MYSQL_STMT structure begin with the prefix mysql_stmt_.

Warning: Incompatible change: The signature of the mysql_stmt_prepare() function was changed to int mysql_stmt_prepare(MYSQL_STMT *stmt, const char *query, unsigned long length). To create a MYSQL_STMT handle, you should use the mysql_stmt_init() function, not mysql_stmt_prepare().

Warning: Incompatible change: The Type output column for SHOW TABLE STATUS now is labeled Engine.

Added the EXAMPLE storage engine.

The mysqld Windows server was renamed to mysqld-debug. See Section 2.3.8, “Selecting a MySQL Server type”.

Added Handler_discover status variable.

Added support for character set conversion and MYSQL_TYPE_BLOB type code in prepared statement protocol.

Added explanation of hidden SELECT of UNION in output of EXPLAIN SELECT statement.

mysql command-line client now supports multiple -e options. (Bug#591)

New myisam_data_pointer_size system variable. See Section 5.2.2, “System Variables”.

The --log-warnings server option now is enabled by default. Disable with --skip-log-warnings.

The --defaults-file=file_name option now requires that the filename must exist (safety fix). (Bug#3413)

mysqld_multi now creates the log in the directory named by datadir (from the [mysqld] section in my.cnf or compiled in), not in /tmp. Thanks to Christian Hammers from Debian Security Team for reporting this. (CVE-2004-0388)

SHOW GRANTS with no FOR clause or with FOR CURRENT_USER() shows the privileges for the current session.

The improved character set support introduced in MySQL 4.1.0 for the MyISAM and HEAP storage engines is now available for InnoDB as well.

A name of “Primary” no longer can be specified as an index name. (That name is reserved for the PRIMARY KEY if the table has one.) (Bug#856)

MySQL now issues a warning when a SET or ENUM column with duplicate values in the list is created. (Bug#1427)

Now SQL_SELECT_LIMIT variable has no influence on subqueries. (Bug#2600)

UNHEX() function implemented. See Section 12.3, “String Functions”.

The mysql command-line client no longer stores in the history file multiple copies of identical queries that are run consecutively.

Multi-line statements in the mysql command-line client now are stored in the history file as a single line.

UUID() function implemented. Note that it does not work with replication yet. See Section 12.9.4, “Miscellaneous Functions”.

Prepared statements with all types of subqueries fixed.

MySQL now supports up to 64 indexes per table.

MyISAM tables now support keys up to 1000 bytes long.

MyISAM and InnoDB tables now support index prefix lengths up to 1000 bytes long.

If you try to create a key with a key part that is too long, and it is safe to auto-truncate it to a smaller length, MySQL now does so. A warning is generated, rather than an error.

The ft_boolean_syntax variable now can be changed while the server is running. See Section 5.2.2, “System Variables”.

REVOKE ALL PRIVILEGES, GRANT FROM user_list is changed to a more consistent REVOKE ALL PRIVILEGES, GRANT OPTION FROM user_list. (Bug#2642)

Internal string-to-number conversion now supports only SQL:2003 compatible syntax for numbers. In particular, '0x10'+0 does not work anymore. (Actually, it worked only on some systems before, such as Linux. It did not work on others, such as FreeBSD or Solaris. Making these queries OS-independent was the goal of this change.) Use CONV() to convert hexadecimal numbers to decimal. Example: CONV(MID('0x10',3),16,10)+0.

mysqlhotcopy now works on NetWare.

ALTER TABLE DROP PRIMARY KEY no longer drops the first UNIQUE index if there is no primary index. (Bug#2361)

Added latin1_spanish_ci (Modern Spanish) collation for the latin1 character set.

Added the ENGINE table option as a synonym for the TYPE option for CREATE TABLE and ALTER TABLE.

Added the --default-storage-engine server option as a synonym for --default-table-type.

Added the storage_engine system variable as a synonym for table_type.

Added init_connect and init_slave system variables. The values should be SQL statements to be executed when each client connects or each time a slave's SQL thread starts, respectively.

C API enhancement: SERVER_QUERY_NO_INDEX_USED and SERVER_QUERY_NO_GOOD_INDEX_USED flags are now set in the server_status field of the MYSQL structure. It is these flags that make the query to be logged as slow if mysqld was started with --log-slow-queries --log-queries-not-using-indexes.

For replication of MEMORY (HEAP) tables: Made the master automatically write a DELETE FROM statement to its binary log when a MEMORY table is opened for the first time since master's startup. This is for the case where the slave has replicated a non-empty MEMORY table, then the master is shut down and restarted: the table is now empty on master; the DELETE FROM empties it on slave too. Note that even with this fix, between the master's restart and the first use of the table on master, the slave still has out-of-date data in the table. But if you use the init-file option to populate the MEMORY table on the master at startup, it ensures that the failing time interval is zero. (Bug#2477)

When a session having open temporary tables terminates, the statement automatically written to the binary log is now DROP TEMPORARY TABLE IF EXISTS instead of DROP TEMPORARY TABLE, for more robustness.

The MySQL server now returns an error if SET SQL_LOG_BIN or SET SQL_LOG_UPDATE is issued by a user without the SUPER privilege (in previous versions it just silently ignored the statement in this case).

Changed that when the MySQL server has binary logging disabled (that is, no --log-bin option was used), then no transaction binary log cache is allocated for connections. This should save binlog_cache_size bytes of memory (32KB by default) for every connection.

Added Binlog_cache_use and Binlog_cache_disk_use status variables that count the number of transactions that used transaction binary log and that had to flush this temporary binary log to disk instead of using only the in-memory buffer. They can be used for tuning the binlog_cache_size system variable.

Added option --replicate-same-server-id.

The Mac OS X Startup Item has been moved from the directory /Library/StartupItems/MySQL to /Library/StartupItems/MySQLCOM to avoid a file name collision with the MySQL Startup Item installed with Mac OS X Server. See Section 2.13.2, “Mac OS X Notes”.

Added option --to-last-log to mysqlbinlog, for use in conjunction with --read-from-remote-server.

The FLOAT and DECIMAL types now obey (precision,scale) settings. (Bug#10897)

Added the mysql_set_local_infile_handler() and mysql_set_local_infile_default() C API functions.

Fixed check of EXPLAIN of UNION. (Bug#3639)

Fixed a bug in a query that used DISTINCT and ORDER BY by column's real name, while the column had an alias, specified in SELECT clause. (Bug#3681)

mysqld could crash when a table was altered and used at the same time. This was a 4.1.2-specific bug. (Bug#3643).

Fixed bug when using impossible WHERE with PROCEDURE ANALYSE(). (Bug#2238).

Fixed security problem in new authentication where password was not checked for changed GRANT accounts until FLUSH PRIVILEGES was executed. (Bug#3404)

Fixed crash of GROUP_CONCAT() on expression with ORDER BY and external ORDER BY in a query. (Bug#3752)

Fixed a bug in ALL/SOME subqueries in case of optimization (key field present in subquery). (Bug#3646)

Fixed a bug in SHOW GRANTS and EXPLAIN SELECT character set conversion. (Bug#3403)

Prepare statements parameter do not cause error message as fields used in select list but not included in ORDER BY list.

UNION statements did not consult SQL_SELECT_LIMIT value when set. This is now fixed properly, which means that this limit is applied to the top level query, unless LIMIT for entire UNION is used.

Fixed a bug in multiple-table UPDATE statements that resulted in an error when one of the tables was not updated but was used in the nested query, contained therein.

Fixed mysql_stmt_send_long_data() behavior on second execution of prepared statement and in case when long data had zero length. (Bug#1664)

Fixed crash on second execution of prepared statement with UNION. (Bug#3577)

Fixed incorrect results of aggregate functions in subquery with empty result set. (Bug#3505)

You can now call mysql_stmt_attr_set(..., STMT_ATTR_UPDATE_MAX_LENGTH) to tell the client library to update MYSQL_FIELD->max_length when doing mysql_stmt_store_result(). (Bug#1647).

Added support for unsigned integer types to prepared statement API (Bug#3035).

Fixed crash in prepared statements when subquery in the FROM clause with parameter used. (Bug#3020)

Fixed unknown error when negative value bind to unsigned. (Bug#3223)

Fixed aggregate function in prepared statements. (Bug#3360)

Incorrect error message when wrong table used in multiple-table DELETE statement in prepared statements. (Bug#3411)

Requiring UPDATE privilege for tables which are not updated in multiple-table UPDATE statement in prepared statements.

Fixed prepared statement support for INSERT, REPLACE, CREATE, DELETE, SELECT, DO, SET and SHOW. All other commands are prohibited via prepared statement interface. (Bug#3398, Bug#3406, Bug#2811)

Fixed a lot of bugs in GROUP_CONCAT(). (Bug#2695, Bug#3381, Bug#3319)

Added optimization that allows for prepared statements using a large number of tables or tables with a large number of columns to be re-executed significantly faster. (Bug#2050)

Fixed bug that caused execution of prepared statements to fail then table that this statement were using left table cache. This bug showed up as if this prepared statement used random garbage as column names or as server crashes. (Bug#3307)

Fixed a problem resulting from setting the character_set_results variable to NULL. (Bug#3296)

Fixed query cache statistics.

Fixed bug in ANALYZE TABLE on a BDB table inside a transaction that hangs server thread. (Bug#2342)

Fixed a symlink vulnerability in the mysqlbug script. (Bug#3284, CVE-2004-0381)

Fixed a bug in parallel repair (myisamchk -p, myisam_repair_threads); sometimes the repair process failed to repair a table. (Bug#1334)

A query that uses both UNION [DISTINCT] and UNION ALL now works correctly. (Bug#1428)

Table default character set affects LONGBLOB columns. (Bug#2821)

CONCAT_WS() makes the server die in case of illegal mix of collations. (Bug#3087)

UTF8 charset breaks joins with mixed column/string constant. (Bug#2959)

Fixed DROP DATABASE to report number of tables deleted.

Fixed bug in privilege checking of ALTER TABLE RENAME. (Bug#3270, CVE-2004-0835)

Fixed memory leak in the client library when statement handle was freed on closed connection (call to mysql_stmt_close after mysql_close). (Bug#3073)

Fixed server segmentation faults when processing malformed prepared statements. (Bug#2795, Bug#2274)

Fixed using subqueries with OR and AND functions. (Bug#2838)

Fixed comparison of tables/database names with --lower_case_table_names option. (Bug#2880)

Removed try to check NULL if index built on column where NULL is impossible in IN subquery optimization. (Bug#2393)

Fixed incorrect parsing of subqueries in the FROM clause. (Bug#2421)

Fixed processing of RAND() in subqueries with static tables. (Bug#2645)

Fixed bug with quoting of table names in mysqldump for various values of sql_mode of server. (Bug#2591)

Fixed bug with storing values that are out of range for DOUBLE and FLOAT columns. (Bug#2082)

Fixed bug with compiling --with-pstack with binutils 2.13.90. (Bug#1661)

Fixed a bug in the GRANT system. When a password was assigned to an account at the global level and then privileges were granted at the database level (without specifying any password), the existing password was replaced temporarily in memory until the next FLUSH PRIVILEGES operation or the server was restarted. (Bug#2953)

Fixed a bug in full-text search on multi-byte character set (such as UTF8) that appeared when a search word was shorter than a matching word from the index (for example, searching for “Uppsala” when table data contain “Uppsa*la”). (Bug#3011)

Fixed a bug that made Max_used_connections to be less than the actual maximum number of connections in use simultaneously.

Fixed calculation of Index_length in HEAP table status for BTREE indexes. (Bug#2719)

Fixed mysql_stmt_affected_rows() call to always return number of rows affected by given statement. (Bug#2247)

Fixed crash in MATCH ... AGAINST() on a phrase search operator with a missing closing double quote. (Bug#2708)

Fixed output of mysqldump --tab. (Bug#2705)

Fix for a bug in UNION operations that prevented proper handling of NULL columns. This happened only if a column in the first SELECT node was NOT NULL. (Bug#2508)

Fix for a bug in UNION operations with InnoDB storage engine, when some columns from one table were used in one SELECT statement and some were used in another SELECT statement. (Bug#2552)

Fixed a few years old bug in the range optimizer that caused a segmentation fault on some very rare queries. (Bug#2698)

Fixed bug with SHOW CREATE TABLE ... which didn't properly double quotes. (Bug#2593)

Queries with subqueries in FROM clause locks all tables at once for now. This also fixed bugs in EXPLAIN of subqueries in FROM output. (Bug#2120)

Fixed bug with mysqldump not quoting “tricky” names correctly. (Bug#2592)

Fix for a bug that prevented table / column privileges from being loaded on startup. (Bug#2546)

Fixed bug in replication with CREATE TABLE ... LIKE ... that resulted in a statement not being written to the binary log. (Bug#2557)

Fixed memory leak in INSERT ... ON DUPLICATE KEY UPDATE .... (Bug#2438)

Fixed bug in the parser, making the syntax CONVERT(expr,type) legal again.

Fixed parsing of short-form IP addresses in INET_ATON(). (Bug#2310)

Fixed a bug in CREATE ... SELECT that sometimes caused a string column with a multi-byte character set (such as utf8) to have insufficient length to hold the data.

Fixed a rare table corruption on adding data (INSERT, REPLACE, UPDATE, etc. but not DELETE) to a FULLTEXT index. (Bug#2417)

Compile the MySQL-client RPM package against libreadline instead of libedit. (Bug#2289)

Fix for a crashing bug that was caused by not setting vio_timeout() virtual function for all protocols. This bug occurred on Windows. (Bug#2025)

Fix for a bug that caused mysql client program to erroneously cache the value of the current database. (Bug#2025)

Fix for a bug that caused client/server communication to be broken when mysql_set_server_option() or mysql_get_server_option() were invoked. (Bug#2207)

Fix for a bug that caused wrong results when CAST() was applied on NULL to signed or unsigned integer column. (Bug#2219)

Fix for a crashing bug that occurred in the mysql client program when database name was longer then expected. (Bug#2221)

Fixed a bug in CHECK TABLE that sometimes resulted in a spurious error Found key at page ... that points to record outside datafile for a table with a FULLTEXT index. (Bug#2190)

Fixed bug in GRANT with table-level privilege handling. (Bug#2178)

Fixed bug in ORDER BY on a small column. (Bug#2147)

Fixed a bug with the INTERVAL() function when 8 or more comparison arguments are provided. (Bug#1561)

Packaging: Fixed a bug in the Mac OS PKG postinstall script (mysql_install_db was called with an obsolete argument).

Packaging: Added missing file mysql_create_system_tables to the server RPM package. This bug was fixed for the 4.1.1 RPMs by updating the MySQL-server RPM from MySQL-server-4.1.1-0 to MySQL-server-4.1.1-1. The other RPMs were not affected by this change.

Fixed a bug in myisamchk and CHECK TABLE that sometimes resulted in a spurious error Found key at page ... that points to record outside datafile for a table with a FULLTEXT index. (Bug#1977)

Fixed a hang in full-text indexing of strings in multi-byte (all besides utf8) charsets. (Bug#2065)

Fixed a crash in full-text indexing of UTF8 data. (Bug#2033)

Replication: a rare race condition in the slave SQL thread that could lead to an incorrect complaint that the relay log is corrupted. (Bug#2011)

Replication: If a client connects to a slave server and issues an administrative statement for a table (for example, OPTIMIZE TABLE or REPAIR TABLE), this could sometimes stop the slave SQL thread. This does not lead to any corruption, but you must use START SLAVE to get replication going again. (Bug#1858)

Replication: in the slave SQL thread, a multiple-table UPDATE could produce an incorrect complaint that some record was not found in one table, if the UPDATE was preceded by a INSERT ... SELECT. (Bug#1701)

Replication: sometimes the master gets a non-fatal error during the execution of a statement but finally the statements succeeds (for example, a write to a MyISAM table first receives "no space left on device" but is able to finally complete, see Section A.4.3, “How MySQL Handles a Full Disk”); the bug was that the master forgot to reset the error code to 0 after success, so the error code got into its binary log, thus making the slave giving false alarms like "did not get the same error as on master". (Bug#2083)

Removed a misleading "check permissions on master.info" from a replication error message, because the cause of the problem could be different from permissions. (Bug#2121)

Fixed a crash when the replication slave was unable to create the first relay log. (Bug#2145)

ALTER DATABASE caused the client to hang if the database did not exist. (Bug#2333)

Multiple-table DELETE statements were never replicated by the slave if there were any --replicate-*-table options. (Bug#2527)

Fixed bug in ALTER TABLE RENAME, when rename to the table with the same name in another database silently dropped destination table if it existed. (Bug#2628)

The MySQL server did not report any error if a statement (submitted through mysql_real_query() or mysql_stmt_prepare()) was terminated by garbage characters. This can happen if you pass a wrong length parameter to these functions. The result was that the garbage characters were written into the binary log. (Bug#2703)

Fixed bug in client library that caused mysql_stmt_fetch and mysql_stmt_store_result() to hang if they were called without prior call of mysql_stmt_execute(). Now they give an error instead. (Bug#2248)

Made clearer the error message that one gets when an update is refused because of the --read-only option. (Bug#2757)

Fixed that --replicate-wild-*-table rules apply to ALTER DATABASE when the table pattern is %, as is the case for CREATE DATABASE and DROP DATABASE. (Bug#3000)

Fixed that when a Rotate event is found by the slave SQL thread in the middle of a transaction, the value of Relay_Log_Pos in SHOW SLAVE STATUS remains correct. (Bug#3017)

Corrected the master's binary log position that InnoDB reports when it is doing a crash recovery on a slave server. (Bug#3015)

Changed the column Seconds_Behind_Master in SHOW SLAVE STATUS to never show a value of -1. (Bug#2826)

Changed that when a DROP TEMPORARY TABLE statement is automatically written to the binary log when a session ends, the statement is recorded with an error code of value zero (this ensures that killing a SELECT on the master does not result in a superfluous error on the slave). (Bug#3063)

Changed that when a thread handling INSERT DELAYED (also known as a delayed_insert thread) is killed, its statements are recorded with an error code of value zero (killing such a thread does not endanger replication, so we thus avoid a superfluous error on the slave). (Bug#3081)

Fixed deadlock when two START SLAVE commands were run at the same time. (Bug#2921)

Fixed that a statement never triggers a superfluous error on the slave, if it must be excluded given the --replicate-* options. The bug was that if the statement had been killed on the master, the slave would stop. (Bug#2983)

The --local-load option of mysqlbinlog now requires an argument.

Fixed a segmentation fault when running LOAD DATA FROM MASTER after RESET SLAVE. (Bug#2922)

mysqlbinlog --read-from-remote-server read all binary logs following the one that was requested. It now stops at the end of the requested file, the same as it does when reading a local binary log. There is an option --to-last-log to get the old behavior. (Bug#3204)

Fixed mysqlbinlog --read-from-remote-server to print the exact positions of events in the "at #" lines. (Bug#3214)

Fixed a rare error condition that caused the slave SQL thread spuriously to print the message Binlog has bad magic number and stop when it was not necessary to do so. (Bug#3401)

Fixed the Exec_master_log_pos column and its disk image in the relay-log.info file to be correct if the master had version 3.23. (The value was too big by six bytes.) This bug does not exist in MySQL 5.0. (Bug#3400)

Fixed mysqlbinlog not to forget to print a USE statement under rare circumstances where the binary log contained a LOAD DATA INFILE statement. (Bug#3415)

Fixed a memory corruption when replicating a LOAD DATA INFILE when the master had version 3.23. Some smaller problems remain in this setup, See Section 6.7, “Replication Features and Known Problems”. (Bug#3422)

Multiple-table DELETE statements were always replicated by the slave if there were some --replicate-*-ignore-table options and no --replicate-*-do-table options. (Bug#3461)

Fixed a crash of the MySQL slave server when it was built with --with-debug and replicating itself. (Bug#3568)

Fixed that in some replication error messages, a very long query caused the rest of the message to be invisible (truncated), by putting the query last in the message. (Bug#3357)

Fixed a bug in REPAIR TABLE that resulted sometimes in a corrupted table, if the table contained FULLTEXT indexes and many words of different lengths that are considered equal (which is possible in certain collations, such as latin1_german2_ci or utf8_general_ci). (Bug#3835)

Fixed a crash of mysqld that was started with binary logging disabled, but with a non-zero value for the expire_logs_days system variable. (Bug#3807)

If server-id was not set using startup options but with SET GLOBAL, the replication slave still complained that it was not set. (Bug#3829)