Dear MySQL users, MySQL 5.5.28 is a new version of the 5.5 production release of the world's most popular open source database. MySQL 5.5.28 is recommended for use on production systems.
MySQL 5.5 includes several high-impact enhancements to improve the performance and scalability of the MySQL Database, taking advantage of the latest multi-CPU and multi-core hardware and operating systems. In addition, with release 5.5, InnoDB is now the default storage engine for the MySQL Database, delivering ACID transactions, referential integrity and crash recovery by default. MySQL 5.5 also provides a number of additional enhancements including: - Significantly improved performance on Windows, with various Windows specific features and improvements - Higher availability, with new semi-synchronous replication and Replication Heart Beat - Improved usability, with Improved index and table partitioning, SIGNAL/RESIGNAL support and enhanced diagnostics, including a new Performance Schema monitoring capability. For a more complete look at what's new in MySQL 5.5, please see the following resources: MySQL 5.5 is GA, Interview with Tomas Ulin: http://dev.mysql.com/tech-resources/interviews/thomas-ulin-mysql-55.html Documentation: http://dev.mysql.com/doc/refman/5.5/en/mysql-nutshell.html Whitepaper: What's New in MySQL 5.5: http://dev.mysql.com/why-mysql/white-papers/mysql-wp-whatsnew-mysql-55.php If you are running a MySQL production level system, we would like to direct your attention to MySQL Enterprise Edition, which includes the most comprehensive set of MySQL production, backup, monitoring, modeling, development, and administration tools so businesses can achieve the highest levels of MySQL performance, security and uptime. http://mysql.com/products/enterprise/ For information on installing MySQL 5.5.28 on new servers, please see the MySQL installation documentation at http://dev.mysql.com/doc/refman/5.5/en/installing.html For upgrading from previous MySQL releases, please see the important upgrade considerations at: http://dev.mysql.com/doc/refman/5.5/en/upgrading.html MySQL Database 5.5.28 is available in source and binary form for a number of platforms from our download pages at: http://dev.mysql.com/downloads/mysql/ The following section lists the changes in the MySQL source code since the previous released version of MySQL 5.5. It may also be viewed online at: http://dev.mysql.com/doc/refman/5.5/en/news-5-5-28.html Enjoy! Changes in MySQL 5.5.28 (2012-September-28) Functionality Added or Changed * The internal interface of the Thread Pool plugin has changed. Old versions of the plugin will work with current versions of the server, but versions of the server older than 5.5.28 will not work with current versions of the plugin. Bugs Fixed * InnoDB: Certain information_schema tables originally introduced in MySQL 5.6 are now also available in MySQL 5.5 and MySQL 5.1: INNODB_BUFFER_PAGE, INNODB_BUFFER_PAGE_LRU, and INNODB_BUFFER_POOL_STATS. (Bug #13113026) * InnoDB: When a SELECT ... FOR UPDATE, UPDATE, or other SQL statement scanned rows in an InnoDB table using a < or <= operator in a WHERE clause, the next row after the affected range could also be locked. This issue could cause a lock wait timeout for a row that was not expected to be locked. The issue occurred under various isolation levels, such as READ COMMITTED and REPEATABLE READ. (Bug #11765218) * Partitioning: For tables using PARTITION BY HASH or PARTITION BY KEY, when the partition pruning mechanism encountered a multi-range list or inequality using a column from the partitioning key, it continued with the next partitioning column and tried to use it for pruning, even if the previous column could not be used. This caused partitions which possibly matched one or more of the previous partitioning columns to be pruned away, leaving partitions that matched only the last column of the partitioning key. This issue was triggered when both of the following conditions were met: 1. The columns making up the table's partitioning key were used in the same order as in the partitioning key definition by a SELECT statement's WHERE clause as in the column definitions; 2. The WHERE condition used with the last column of the partitioning key was satisfied only by a single value, while the condition testing some previous column from the partitioning key was satisfied by a range of values. An example of a statement creating a partitioned table and a query against this for which the issue described above occurred is shown here: CREATE TABLE t1 ( c1 INT, c2 INT, PRIMARY KEY(c2, c1) ) PARTITION BY KEY() # Use primary key as partitioning key PARTITIONS 2; SELECT * FROM t1 WHERE c2 = 2 AND c1 <> 2; This issue is resolved by ensuring that partition pruning skips any remaining partitioning key columns once a partition key column that cannot be used in pruning is encountered. (Bug #14342883) * Partitioning: The buffer for the row currently read from each partition used for sorted reads was allocated on open and freed only when the partitioning handler was closed or destroyed. For SELECT statements on tables with many partitions and large rows, this could cause the server to use excessive amounts of memory. This issue has been addressed by allocating buffers for reads from partitioned tables only when they are needed and freeing them immediately once they are no longer needed. As part of this fix, memory is now allocated for reading from rows only in partitions that have not been pruned (see Partition Pruning (http://dev.mysql.com/doc/refman/5.5/en/partitioning-pruning.h tml)). (Bug #13025132) References: See also Bug #11764622, Bug #14537277. * Replication: On 64-bit Windows platforms, values greater than 4G for the max_binlog_cache_size and max_binlog_stmt_cache_size system variables were truncated to 4G. This caused LOAD DATA INFILE to fail when trying to load a file larger than 4G in size, even when max_binlog_cache_size was set to a value greater than this. (Bug #13961678) * Replication: In master-master replication with --log-slave-updates enabled, setting a user variable and then performing inserts using this variable caused the Exec_master_log_position column in the output of SHOW SLAVE STATUS not to be updated. (Bug #13596613) * The RPM spec file now also runs the test suite on the new binaries, before packaging them. (Bug #14318456) * The libmysqlclient_r client library exported symbols from yaSSL that conflict with OpenSSL. If a program linked against that library and libcurl, it could crash with a segmentation fault. (Bug #14068244) * The argument for LIMIT must be an integer, but if the argument was given by a placeholder in a prepared statement, the server did not reject noninteger values such as '5'. (Bug #13868860) * The Thread Pool plugin did not respect the wait_timeout timeout for client sessions. (Bug #13699303) * CHECK TABLE and REPAIR TABLE could crash if a key definition differed in the .frm and .MYI files of a MyISAM table. Now the server produces an error. (Bug #13555854) * A query for a FEDERATED table could return incorrect results when the underlying table had a compound index on two columns and the query included an AND condition on the columns. (Bug #12876932) * mysqlhotcopy failed for databases containing views. (Bug #62472, Bug #13006947, Bug #12992993) * The argument to the --ssl-key option was not verified to exist and be a valid key. The resulting connection used SSL, but the key was not used. (Bug #62743, Bug #13115401) * Adding a LIMIT clause to a query containing GROUP BY and ORDER BY could cause the optimizer to choose an incorrect index for processing the query, and return more rows than required. (Bug #54599, Bug #11762052) * mysqlbinlog did not accept input on the standard input when the standard input was a pipe. (Bug #49336, Bug #11757312) On behalf of the MySQL/ORACLE Build Team Hery Ramilison -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql