MySQL AB last week released an alpha preview of the latest version of its flagship open-source database,
MySQL 5.0.
The company will announce pricing and release dates when MySQL 5.0 is formally announced in early January, a spokeswoman said. MySQL's site lists potential new features, including stored procedures based on the SQL-99 framework, which is similar to Oracle PL/SQL. According to documentation on the site, the SQL-99 framework accommodates external languages and provides compatibility with PL/SQL and T-SQL, for example.
Other planned features include elementary cursor support, the ability to specify explicitly that an RTREE index be created for MyISAM tables and dynamic length rows for HEAP tables.
In a move that promises to enhance standards compliance, improve portability and ease migration, the new release may include true VARCHAR support. This enhancement will support columns longer than 255 characters with no stripping of trailing whitespace.
If planned enhancements are implemented, MySQL 5.0 should also be speedier than previous releases. One enhancement will affect the SHOW COLUMNS FROM table_name command, which is used by the MySQL client to enable expanded column names. A targeted enhancement for 5.0 is that the command opens only the definition file as opposed to the whole table. In addition, DELETE on MYISAM tables should be able to use record cache. Better in-memory (HEAP) tables will also resize rows dynamically and handle rows faster with less copying.
Based on the planned enhancements list, MySQL 5.0 will gain better internationalization features as well. When using the SET CHARACTER SET command, the software will translate the whole query instead of translating only strings. Such translated characters can be used in database, table and column names.
Finally, Version 5.0 is slated to resolve an issue with the RENAME TABLE command. In the current version of the database, using this command in an active MERGE table renders the table vulnerable to corruption.
Although Version 5.0 is still in alpha, Uppsala, Sweden-based MySQL does recommend the product's Standard binaries for most users. MySQL has incorporated the InnoDB storage engine—an open-source transactional storage engine from Innobase Oy Inc., of Helsinki, Finland—into those binaries. A Max version also includes features such as the Berkeley DB storage engine and other features that haven't yet undergone thorough testing, including OpenSSL support, user-defined functions and BIG_TABLE support. Future versions of Standard binaries will include those features after they have matured and are stable, according to MySQL's site.
The MySQL site warns that Debug binaries now include extra debug information that is not intended for general consumption, because the extra code may slow down database instances.
Editor's note: This story was updated to reflect the fact that new features are based on plans detailed on MySQL's site and have not as yet been verified by the company.
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