1.5 MySQL Development History

This section describes the general MySQL development history, provides an overview about features that have been implemented in previous series and that are new in MySQL 5.5, the release series covered in this manual. The maturity level of this release series is general availability. Information about maturity levels can be found in Section 2.1.1, “Which MySQL Version and Distribution to Install”.

Before upgrading from one release series to the next, please see the notes in Section 2.11.1, “Upgrading MySQL”.

The most requested features and the versions in which they were implemented are summarized in the following table.

FeatureMySQL Series
R-trees4.1 (for the MyISAM storage engine)
Stored procedures and functions5.0
XA transactions5.0
Triggers5.0 and 5.1
Event scheduler5.1
Pluggable storage engine API5.1
Plugin API5.1
InnoDB Plugin5.1
Row-based replication5.1
Server log tables5.1
Scalability and performance improvements5.1 (with InnoDB Plugin)
DTrace support5.5
InnoDB as default storage engine5.5
Semisynchronous replication5.5
SIGNAL/RESIGNAL support in stored routines5.5
Performance Schema5.5
Supplementary Unicode characters5.5