持續蓬勃發展的資料庫軟體Mysql官方將Mysql 5列為能作為正式平台之用，日前也釋出了各平台的Mysql 5.0.19版本，這是睽違數個月的更新，更動幅度與修正、加強的地方非常多。
Mysql 5.0.19更新下載頁面
Mysql 5.0.19功能與bug更新列表
新增加的功能如下：
Incompatible change: The InnoDB storage engine no longer ignores trailing spaces when comparing BINARY or VARBINARY column values. This means that (for example) the binary values 'a' and 'a ' are now regarded as unequal any time they are compared, as they are in MyISAM tables. (Bug #14189)
See Section 11.4.2, “The BINARY and VARBINARY Types” for more information about the BINARY and VARBINARY types.
The result type of the GROUP_CONCAT() function is now VARCHAR only if the the value of the group_concat_max_len system variable is less than or equal to 512. Otherwise, this funciton returns a BLOB. (Bug #14169)
Added the mysql_upgrade program that checks all tables for incompatibilities with the current version of MySQL Server and repairs them if necessary. This program should be run for each MySQL upgrade (rather than mysql_fix_privilege_tables). See Section 5.6.2, “mysql_upgrade — Check Tables for MySQL Upgrade”.
Added the FOR UPGRADE option for the CHECK TABLE statement. This option checks whether tables are incompatible with the current version of MySQL Server. Also added the –check-upgrade to mysqlcheck that invokes CHECK TABLE with the FOR UPGRADE option.
mysql no longer terminates data value display when it encounters a NUL byte. Instead, it displays NUL bytes as spaces. (Bug #16859)
Added the –wait-timeout option to mysqlmanager to allow configuration of the timeout for dropping an inactive connection, and increased the default timeout from 30 seconds to 28,800 seconds (8 hours). (Bug #12674)
A number of performance issues were resolved that had previously been encountered when using statements that repeatedly invoked stored functions. For example, calling BENCHMARK() using a stored function executed much more slowly than when invoking it with inline code that accomplished the same task. In most cases the two should now execute with approximately the same speed. (Bug #15014, Bug #14946)
libmysqlclient now uses versioned symbols with GNU ld. (Bug #3074)
NDB Cluster: More descriptive warnings are now issued when inappropriate logging parameters are set in config.ini. (Formerly, the warning issued was simply Could not add logfile destination.) (Bug #11331)
Added the –port-open-timeout option to mysqld to control how many seconds the server should wait for the TCP/IP port to become free if it cannot be opened. (Bug #15591)
Repeated invocation of my_init() and my_end() caused corruption of character set data and connection failure. (Bug #6536)
Two new Hungarian collations are included: utf8_hungarian_ci and ucs2_hungarian_ci. These support the correct sort order for Hungarian vowels. However, they do not support the correct order for sorting Hungarian consonant contractions; this issue will be fixed in a future release.
Wording of error 1329 changed to No data – zero rows fetched, selected, or processed. (Bug #15206)
The INFORMATION_SCHEMA now skips data contained in unlistable/unreadable directories rather than returning an error. (Bug #15851)
InnoDB now caches a list of unflushed files instead of scanning for unflushed files during a table flush operation. This improves performance when –innodb-file-per-table is set on a system with a large number of InnoDB tables. (Bug #15653)
The message for error 1109 changed from Unknown table … in order clause to Unknown table … in field list. (Bug #15091)
The mysqltest utility now converts all CR/LF combinations to LF to allow test cases intended for Windows to work properly on UNIX-like systems. (Bug #13809)
The mysql_ping function will now retry if the reconnect flag is set and error CR_SERVER_LOST is encountered during the first attempt to ping the server. (Bug #14057)
mysqldump now surrounds the DEFINER, SQL SECURITY DEFINER and WITH CHECK OPTION clauses of a CREATE VIEW statement with "not in version" comments to prevent errors in earlier versions of MySQL. (Bug #14871)
New charset command added to mysql command-line client. By typing charset name or C name (such as C UTF8), the client character set can be changed without reconnecting. (Bug #16217)
Bugs fixed:
Setting the myisam_repair_threads system variable to a value larger than 1 could cause corruption of large MyISAM tables. (Bug #11527)
When using the GROUP_CONCAT() function where the group_concat_max_len system variable was greater than 512, the type of the result was BLOB only if the query included an ORDER BY clause; otherwise the result was a VARCHAR. (Bug #14169)
The length of a VARCHAR() column that used the utf8 character set would increase each time the table was re-created in a stored procedure or prepared statement, eventually causing the CREATE TABLE statement to fail. (Bug #13134)
type_decimal failed with the prepared statement protocol. (Bug #17826)
The MySQL server could crash with out of memory errors when performing aggregate functions on a DECIMAL column. (Bug #17602)
A stored procedure failed to return data the first time it was called per connection. (Bug #17476)
Using DROP FUNCTION IF EXISTS func_name to drop a user-defined function caused a server crash if the server was running with the –skip-grant-tables option. (Bug #17595)
Using ALTER TABLE to increase the length of a BINARY(M) column caused column values to be padded with spaces rather than 0x00 bytes. (Bug #16857)
A large BIGINT value specified in a WHERE clause could be treated differently depending on whether it is specified as a quoted string. (For example, WHERE bigint_col = 17666000000000000000 versus WHERE bigint_col = '17666000000000000000'). (Bug #9088)
A natural join between INFORMATION_SCHEMA tables failed. (Bug #17523)
A memory leak caused warnings on slaves for certain statements that executed without warning on the master. (Bug #16175)
The embedded server did not allow binding of columns to the MYSQL_TYPE_VAR_STRING data type in prepared statements. (Bug #12070)
The embedded server failed various tests in the automated test suite. (Bug #9630, Bug #9631, Bug #9633, Bug #10801, Bug #10911, Bug #10924, Bug #10925, Bug #10926, Bug #10930, Bug #15433)
Instance Manager erroneously accepted a list of instance identifiers for the START INSTANCE and STOP INSTANCE commands (should accept only a single identifier). (Bug #12813)
For a transaction that used MyISAM and InnoDB tables, interruption of the transaction due to a dropped connection on a master server caused slaves to lose synchrony. (Bug #16559)
SELECT with GROUP BY on a view can cause a server crash. (Bug #16382)
If the query optimizer transformed a GROUP BY clause in a subquery, it did not also transform the HAVING clause if there was one, producing incorrect results. (Bug #16603)
SUBSTRING_INDEX() could yield inconsistent results when applied with the same arguments to consecutive rows in a query. (Bug #14676)
The parser allowed CREATE AGGREGATE FUNCTION for creating stored functions, even though AGGREGATE does not apply. (It is used only for CREATE FUNCTION only when creating user-defined functions.) (Bug #16896)
Data truncations on non-UNIQUE indexes could crash InnoDB when using multi-byte character sets. (Bug #17530)
Triggers created without BEGIN and END clauses could not be properly restored from a mysqldump file. (Bug #16878)
The RENAME TABLE statement did not move triggers to the new table. (Bug #13525)
Clients compiled from source with the –without-readline did not save command history from session to session. (Bug #16557)
Stored routines that contained only a single statement were not written properly to the dumpfile when using mysqldump. (Bug #14857)
For certain MERGE tables, the optimizer wrongly assumed that using index_merge/intersection was too expensive. (Bug #17314)
Executing a SHOW CREATE VIEW query of an invalid view caused the mysql_next_result function of libMySQL.dll to hang. (Bug #15943)
BIT fields were not properly handled when using row-based replication. (Bug #13418)
Issuing GRANT EXECUTE on a procedure would display any warnings related to the creation of the procedure. (Bug #7787)
NDB Cluster: ndb_delete_all would run out of memory on tables containing BLOB columns. (Bug #16693)
NDB Cluster: UNIQUE keys in Cluster tables were limited to 225 bytes in length. (Bug #15918)
In a highly concurrent environment, a server crash or deadlock could result from execution of a statement that used stored functions or activated triggers coincident with alteration of the tables used by these functions or triggers. (Bug #16593)
Previously, a stored function invocation was written to the binary log as DO func_name() if the invocation changes data and occurs within a non-logged statement, or if the function invokes a stored procedure that produces an error. These invocations now are logged as SELECT func_name() instead for better control over error code checking (slave servers could stop due to detecting a different error than occurred on the master). (Bug #14769)
CHECKSUM TABLE returned different values on MyISAM table depending on whether the QUICK or EXTENDED options were used. (Bug #8841)
MySQL server dropped client connection for certain SELECT statements against views defined that used MERGE algorithm. (Bug #16260)
A call to the IF() function using decimal arguments could return incorrect results. (Bug #16272)
A statement containing GROUP BY and HAVING clauses could return incorrect results when the HAVING clause contained logic that returned FALSE for every row. (Bug #14927)
Using GROUP BY on column used in WHERE clause could cause empty set to be returned. (Bug #16203)
For a MySQL 5.0 server, using MySQL 4.1 tables in queries with a GROUP BY clause could result in buffer overrun or a server crash. (Bug #16752)
SET sql_mode = N, where N > 31, did not work properly. (Bug #13897)
NDB Cluster: Cluster log file paths were truncated to 128 characters. They may now be as long as MAX_PATH (the maximum path length permitted by the operating system). (Bug #17411)
The mysql_stmt_store_result() C API function could not be used for a prepared statement if a cursor had been opened for the statement. (Bug #14013)
The mysql_stmt_sqlstate() C API function incorrectly returned an empty string rather than '00000' when no error occurred. (Bug #16143)
Using the TRUNCATE() function with a negative number for the second argument on a BIGINT column returned incorrect results. (Bug #8461)
Instance Manager searched wrong location for password file on some platforms. (Bug #16499)
NDB Cluster: Following multiple forced shutdowns and restarts of data nodes, DROP DATABASE could fail. (Bug #17325)
NDB Cluster: An UPDATE with an inner join failed to match any records if both tables in the join did not have a primary key. (Bug #17257)
NDB Cluster: A DELETE with a join in the WHERE clause failed to retrieve any records if both tables in the join did not have a primary key. (Bug #17249)
The error message returned by perror –ndb was prefixed with OS error code: instead of NDB error code:. (Bug #17235)
NDB Cluster: In some cases, LOAD DATA INFILE did not load all data into NDB tables. (Bug #17081)
NDB Cluster: The REDO log would become corrupted (and thus unreadable) in some circumstances, due to a failure in the query handler. (Bug #17295)
NDB Cluster: No error message was generated for setting NoOfFragmentLogFiles too low. (Bug #13966)
NDB Cluster: No error message was generated for setting MaxNoOfAttributes too low. (Bug #13965)
Binary distributions for Solaris contained files with group ownership set to the non-existing wheel group. Now the bin group is used. (Bug #15562)
The DECIMAL data type was not being handled correctly with prepared statements. (Bug #16511)
The SELECT privilege was required for triggers that performed no selects. (Bug #15196)
The UPDATE privilege was required for triggers that performed no updates. (Bug #15166)
CAST(… AS TIME) operations returned different results when using versus not using prepared-statement protocol. (Bug #15805)
Improper memory handling for stored routine variables could cause memory overruns and binary log corruption. (Bug #15588)
Killing a long-running query containing a subquery could cause a server crash. (Bug #14851)
A FULLTEXT query in a prepared statement could result in unexpected behavior. (Bug #14496)
A RETURN statement within a trigger caused a server crash. RETURN now is disallowed within triggers. To exit immediately, use LEAVE. (Bug #16829)
STR_TO_DATE(1,NULL) caused a server crash. (Bug #15828)
An invalid stored routine could not be dropped. (Bug #16303)
When evaluation of the test in a CASE failed in a stored procedure that contained a CONTINUE handler, execution resumed at the beginning of the CASE statement instead of at the end. (Bug #16568)
An INSERT statement in a stored procedure corrupted the binary log. (Bug #16621)
When MyODBC or any other client called my_init()/my_end() several times, it caused corruption of charset data stored in once_mem_pool. (Bug #11892)
When multiple handlers are created for the same MySQL error number within nested blocks, the outermost handler took precedence. (Bug #15011)
Certain LEAVE statements in stored procedures were not properly optimized. (Bug #15737)
Setting InnoDB path settings to an empty string caused InnoDB storage engine to crash upon server startup. (Bug #16157)
InnoDB used full explicit table locks in trigger processing. (Bug #16229)
Server crash when dropping InnoDB constraints named TABLENAME_ibfk_0. (Bug #16387)
Corrected race condition when dropping the adaptive hash index for a B-tree page in InnoDB. (Bug #16582)
MYSQL_OPT_RECONNECT option was modified by calls to the mysql_real_connect() function. (Bug #15719)
InnoDB: After upgrading an InnoDB table having a VARCHAR BINARY column created in MySQL 4.0 to MySQL 5.0, update operations on the table would cause the server to crash. (Bug #16298)
Trying to compile the server on Windows generated a stack overflow warning due to a recursive definition of the internal Field_date::store() method. (Bug #15634)
The use of LOAD INDEX within a stored routine was permitted and caused the server to crash. Note: LOAD INDEX statements within stored routines are not supported, and now yield an error if attempted. This behavior is intended. (Bug #14270)
The mysqlbinlog utility did not output DELIMITER statements, causing syntax errors for stored routine creation statements. (Bug #11312)
NDB Cluster returned incorrect Can't find file error for OS error 24, changed to Too many open files. (Bug #15020)
Performing a RENAME TABLE on an InnoDB table when the server is started with the –innodb-file-per-table and the data directory is a symlink caused a server crash. (Bug #15991)
The mysql_stmt_attr_get function returned an unsigned int instead of a boolean for STMT_ATTR_UPDATE_MAX_LENGTH. (Bug #16144)
Multi-byte path names for LOAD DATA and SELECT … INTO OUTFILE caused errors. Added the character_set_filesystem system variable, which controls the interpretation of string literals that refer to filenames. (Bug #12448)
Certain subqueries where the inner query is the result of a aggregate function would return different results on MySQL 5.0 than on MySQL 4.1. (Bug #15347)
Attempts to create FULLTEXT indexes on VARCHAR columns larger than 1000 bytes resulted in error. (Bug #13835)
Characters in the gb2312 and euckr character sets which did not have Unicode mappings were truncated. (Bug #15377)
Certain nested LEFT JOIN operations were not properly optimized. (Bug #16393)
GRANT statements specifying schema names that included underscore characters (i.e. my_schema) did not match if the underscore was escaped in the GRANT statement (i.e. GRANT ALL ON `my_schema` …). (Bug #14834)
Running out of diskspace in the location specified by the tmpdir option resulted in incorrect error message. (Bug #14634)
Test suite sp test left behind tables when the test failed that could cause future tests to fail. (Bug #15866)
UPDATE statement crashed multi-byte character set FULLTEXT index if update value was almost identical to initial value only differing in some spaces being changed to . (Bug #16489)
A SELECT query which contained a GROUP_CONCAT() and an ORDER BY clause against the INFORMATION_SCHEMA resulted in an empty result set. (Bug #15307)
The –replicate-do and –replicate-ignore option
