MySQL 5.5 released the Milestone 2 developer version yesterday. Prior to this, the last stable version of MySQL was MySQL 5.1, released a year ago. For MySQL 5.5, the team adopted a new version upgrade model to incorporate some new features planned to debut in MySQL 6.0. What does the new model bring to MySQL? Let's take a look. Although Oracle's acquisition of Sun is still awaiting the final result, and the industry is also very worried about the future fate of the open source database MySQL, Sun's developers continue to work hard to develop the open source database. One of the fruits of their labor is the recently released MySQL 5.5 Milestone 2 developer version. The new version introduces many new features, some of which were originally prepared for MySQL 6.0.
For the past two years, the MySQL community has been discussing MySQL version 6.0. The most recent stable release of MySQL is version 5.1, which debuted a year ago after much controversy and repeated delays.
Following the launch of MySQL version 5.1, the MySQL development team changed the model for launching new versions to support a faster and more stable version upgrade cycle. Since then, some features planned to be launched in version 6.0 have been unveiled in advance.
Sun spokesman Steve Curry noted, "As part of this new model, we have implemented many features originally planned for version 6.0 into MySQL version 5.5 ahead of schedule, and there will certainly be a MySQL 6.0 version in the future. , but we haven’t decided yet what new upgraded features it will include.”
Currie said he believes users will be excited about the many new features in the MySQL 5.5 milestone version, including performance and scalability improvements.
◆MySQL 5.5 adds a new semi-synchronous replication function. Now, in addition to the default asynchronous replication function, MySQL users have another replication function to choose from.
According to the MySQL 5.5 version announcement, "Before returning to the session executing the replicated transaction, the Master will suspend execution of the commit until the slave confirms that it has received and recorded the replicated transaction." In contrast, in the asynchronous replication function, the Master The client will log the event directly without knowing whether the slave actually processed the replication transaction.
◆MySQL 5.5 adds improved partitioning syntax. In this new version of the database, there are many new database partitioning options, including user-defined RANGE COLUMNS partitioning options.
MySQL official said, "When users partition a table based on RANGE COLUMNS or LIST COLUMNS, they can define ranges or lists based on multi-column values, and can associate up to 16 columns."
◆In the MySQL 5.5 milestone version, support for the SQL standard SINGAL and RESINGNAL statements has also been added. Both the SINGNAL statement and the RESINGNAL statement ensure that an error status can be returned to the database Hander.
MySQL official said, "Without SINGNAL, if you want the program to return an error, you must resort to roundabout solutions such as deliberately pointing to a bad table. RESINGNAL can both handle errors and return error information. Otherwise, by executing within the Handler A SQL statement that activates the Handler will be destroyed."
From MySQL 5.1 to MySQL 5.5
For now, the MySQL 5.5 milestone version is still a developer version and is not suitable for use in a formal production environment. But this does not mean that Sun does not want people to try this new version. Currie said that the work of MySQL 5.5 testers is very important and can help Sun receive feedback and estimate progress.
If you want to upgrade from the current version 5.1 to 5.5, which is still in the development version, users do not need to explore the upgrade method on their own. Curry said, "We are providing a large amount of migration information to help users complete the upgrade process and encourage them to become familiar with the new version's functions. We do not want users to encounter any trouble in this process."
As for when MySQL 5.5 will end the current developer milestone version and be officially released, Curry said it has not yet been finalized.
He said, "We will have a clearer idea after getting preliminary feedback from the community, customers and internal QA in the future. Through this new milestone version model, we are working hard to improve all functions of the database. The initial user feedback is satisfactory. , but it’s too early to say when it will be officially released. We are excited to bring this new version to the community and they will tell us how to develop this software.”