MySQL Community Edition is a freely downloadable version of the world's most popular open source database that is supported by an active community of open source developers and enthusiasts.
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
# Bugs Fixed
* InnoDB Storage Engine: This fix improves the performance of instrumentation code for InnoDB buffer pool operations.
* InnoDB Storage Engine: Data from BLOB columns could be lost if the server crashed at a precise moment when other columns were being updated in an InnoDB table.
* InnoDB Storage Engine: Lookups using secondary indexes could give incorrect matches under a specific set of conditions. The conditions involve an index defined on a column prefix, for a BLOB or other long column stored outside the index page, with a table using the Barracuda file format.
* InnoDB Storage Engine: This fix corrects cases where the MySQL server could hang or abort with a long semaphore wait message. (This is a different issue than when these symptoms occurred during a CHECK TABLE statement.)
* Replication: Issuing the following statements, in the order shown, could cause a deadlock between the user thread and I/O thread:
STOP SLAVE SQL_THREAD;
* Internal conversion of zero to binary and back could yield a result with incorrect precision.
* Valgrind warnings generated by filesort operations were fixed.
* Several improvements were made to the libedit library bundled with MySQL distributions, and that is available for all platforms that MySQL supports except Windows.
- Navigation keys did not work for UTF-8 input.
- Word navigation and delete operations did not work for UTF-8 input with Cyrillic characters.
- Nonlatin characters were corrupted in overwrite mode for UTF-8 input.
- Long queries caused the statement history file to become corrupted.
- The Alt key caused history operations to fail.
* The help message for mysql_install_db did not indicate that it supports the --defaults-file, --defaults-extra-file and --no-defaults options.
* An assertion designed to detect zero-length sort keys also was raised when the entire key set fit in memory.
* myisampack could create corrupt FULLTEXT indexes when compressing tables.
* OPTIMIZE TABLE could corrupt MyISAM tables if myisam_use_mmap was enabled.
* If MySQL was configured with --without-plugin-innobase and --with-plugin-innodb_plugin, to suppress building the built-in InnoDB storage engine and build the InnoDB Plugin instead, the innochecksum utility was not built.
* A linking problem prevented the FEDERATED storage engine plugin from loading.
* On Fedora, certain accesses to /var/lib/mysql/HOSTNAME.err were blocked by SELinux policy, which made the server fail at startup with the message: Manager of pid-file quit without updating file
* For FEDERATED tables, loss of connection to the remote table during some insert operations could cause a server crash.