Thursday, March 18, 2010

MySQL 5.1.45

MySQL is a relational database management system (RDBMS) that has more than 6 million installations. MySQL stands for "My Structured Query Language". The program runs as a server providing multi-user access to a number of databases.MySQL project has made its source code available under the terms of the GNU General Public License, as well as under a variety of proprietary agreements. MySQL is owned and sponsored by a single for-profit firm, the Swedish company MySQL AB, now a subsidiary of Sun Microsystems. As of 2009 Oracle Corporation began the process of acquiring Sun Microsystems.MySQL is often used in free software projects that require a full-featured database management system, such as WordPress, phpBB and other software built on the LAMP software stack. It is also used in very high-scale World Wide Web products including Wikipedia, Google and Facebook
MySQL's HOMEPAGE: www.mysql.com
MySQL's TYPE: (Open Source)
MySQL's DOWNLOAD: MySQL 5.1.45
MySQL's SIZE: 39.61 MB
MySQL's GOOGLE HITS: 22 Millions +

MySQL delivers enterprise features, including:

  • Partitioning to improve performance and management of very large database environments
  • Row-based/Hybrid Replication for improved replication security
  • Event Scheduler to create and schedule jobs that perform various database tasks
  • XPath Support
  • Dynamic General/Slow Query Log
  • Performance/Load Testing Utility (mysqlslap)
  • Improved! Full Text Search (faster, new dev templates)
  • Improved! Archive engine (better compression, more features)
  • Improved! User session and problem SQL identification
  • Improved! MySQL embedded library (libmysqld)
  • Additional INFORMATION_SCHEMA objects
  • Faster data import operations (parallel file load)
  • ACID Transactions to build reliable and secure business critical applications
  • Stored Procedures to improve developer productivity
  • Triggers to enforce complex business rules at the database level
  • Views to ensure sensitive information is not compromised
  • Information Schema to provide easy access to metadata
  • Pluggable Storage Engine Architecture for maximum flexibility
  • Archive Storage Engine for historical and audit data

MySQL 5.1.45 Improvements:

# Bugs fixed:

* Partitioning: Attempting to drop a partitioned table from one connection while waiting for the completion of an ALTER TABLE that had been issued from a different connection, and that changed the storage engine used by the table, could cause the server to crash. (Bug#42438)
* Replication: Adding an index to a table on the master caused the slave to stop logging slow queries to the slow query log. (Bug#50620)
* Replication: Queries which were written to the slow query log on the master were not written to the slow query log on the slave. (Bug#23300) See also Bug#48632.
* mysqld_multi failed due to a syntax error in the script. (Bug#51468)
* Referring to a subquery result in a HAVING clause could produce incorrect results. (Bug#50995)
* Use of filesort plus the join cache normally is preferred to a full index scan. But it was used even if the index is clustered, in which case, the clustered index scan can be faster. (Bug#50843)
* For debug builds, SHOW BINARY LOGS caused an assertion to be raised if binary logging was not enabled. (Bug#50780)
* Incorrect handling of BIT columns in temporary tables could lead to spurious duplicate-key errors. (Bug#50591)
* Full-text queries that used the truncation operator (*) could enter an infinite loop. (Bug#50351)
* mysqltest no longer lets you execute an SQL statement on a connection after doing a send command, unless you do a reap first. This was previously accepted but could produce unpredictable results. (Bug#49269)
* For debug builds on Windows, warnings about incorrect use of debugging directives were written to the error log. The directives were rewritten to eliminate these messages. (Bug#49025)
* Building MySQL on Fedora Core 12 64-bit failed, due to errors in comp_err. (Bug#48864)
* An ARZ file missing from the database directory caused the server to crash. (Bug#48757)
* Slow CALL statements were not always logged to the slow query log because execution time for multiple-statement stored procedures was assessed incorrectly. (Bug#47905)
* Failure to open a view with a nonexistent DEFINER was improperly handled and the server would crash later attempting to lock the view. (Bug#47734)
* If EXPLAIN encountered an error in the query, a memory leak occurred. (Bug#45989)
* Grouping by a subquery in a query with a DISTINCT aggregate function led to incorrect and unordered grouping values. (Bug#45640)
* Propagation of a large unsigned numeric constant in WHERE expressions could lead to incorrect results. This also affected EXPLAIN EXTENDED, which printed incorrect numeric constants in such transformed WHERE expressions. (Bug#45360)
* Valgrind warnings about uninitialized variables in optimizer code were silenced. (Bug#45195)
* flush_cache_records() did not correctly check for errors that should cause statement execution to stop, leading to a server crash. (Bug#39022)
* When building MySQL when using a different target directory (for example using the VPATH environment variable), the build of the embedded readline component would fail. (Bug#35250)
* INSERT INTO ... VALUES(DEFAULT) failed to insert the correct value for ENUM columns. For MyISAM tables, an empty value was inserted. For CSV tables, the table became corrupt. (Bug#33717)

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