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  • MySQL
    December 15, 2009

MySQL 5.5 milestone 2 released

Guest Author


MySQL has released its second milestone of the new series, inaugurated this year with MySQL 5.4.

The new installment, MySQL 5.5-m2, has several new features, of which the most notables ones are semi-synchronous replication, exception handling through in stored routines through SIGNAL and RESIGNAL, and partitioning enhancements.

A quick overview of partitioning and semi-synchronous replication is available in this blog. Hours after the release, Roland Bouman published a very charming example of how useful the new SIGNAL feature can be.

The new release, available in the usual MySQL download pages, comes with an enhanced user manual.

This release shows that MySQL is moving forward in the path of its new development cycle, leaving behind its previous inflexible model that was stalling innovation and contribution. With this agile cycle, mature features are added more dynamically, while the ones in need of more development are sent to the next milestone, without side effects.

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Comments ( 4 )
  • sapphirecat Friday, December 18, 2009

    You know, these MySQL releases have gotten really confusing. Just recently, there was a huge banner on dev.mysql.com to download 5.4 for "stability and performance", which turned out to be beta if you clicked on it, with 5.1 being the (recommended) GA release.

    Now 5.4 and the giant banners have basically vanished from the site, replaced by some understated news of the 5.5 beta (calling it "m2" as if there was an "m1" there in the past). In the download section, 5.1 is still the recommended GA release.

    Is MySQL going on permanent beta or something? Did 5.4 ever stabilize? All my weak search skills can find are the announcement of the new "drop unstable features from branches" development plans, and talking about Azalea.

  • Giuseppe Maxia Saturday, December 19, 2009

    Version 5.1 is still the recommended GA release.

    Version 5.4 has evolved into 5.5.

    MySQL is not a permanent beta. This is the new release model.

    Please read Kaj's blog, already mentioned in the text, for more information.


  • WTFever Monday, December 21, 2009

    Ditto for sapphirecat's comments. Where is the explanation of what happened to 5.4? I was under the impression that 5.4 would be first be released towards the end of 2009.

    5.4 looked to be a nice interim release with primarily bug fixes and performance enhancements that could ship on-time.

    Now it's "evolved" into 5.5, grown new features and will be released mid-2010?


    Wonder now if I'll check back in mid-2010 and see a new "evolved" 5.6 scheduled for 2011? ugh.

  • Jeffrey Pugh Monday, December 21, 2009

    Giuseppe has given the short answer and I strongly suggest reading Kaj's blog.

    Antony, it's called Milestone 2 because 5.4 was Milestone 1 on the way to the next GA.

    Thanks for your comments about our communication - we can always improve it. But in trying to be open about our development process, you get to hear more than you probably want about what we're doing when plans change.

    That all said, I suggest you and others are probably more interested in what's in Milestone 2. I'd encourage you to download it and try it.

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