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_posts/2012-05-09-bullet-4-released.markdown

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+---
+layout: post
+title: bullet 4.0.0 released
+categories:
+- rails
+- bullet
+---
+[bullet][1] is designed to help you reduce the number of db queries, such as
+adding eager loading to kill n+1 queries and removing unused eager
+loadings.
+
+bullet works well in activerecord from 2.1 to 3.2 before, today I
+released bullet 4.0.0, it starts to support mongoid (>= 2.4.1) now.
+
+Why does bullet need to support mongoid?
+Does mongo also have n+1 queries issue?
+
+The answer is yes, check out the [performance metric of mongoid eager
+loading][2], about 40% performance improved. 1 year ago I already
+created a gem [mongoid-eager-loading][3] to add eager loading feature
+in mongoid, it is deprecated as mongoid has already supported eager
+loading natively.
+
+Be aware that bullet for mongoid doesn't support 2 level deep eager
+loading and counter cache because they are not supported in mongoid so
+far.
+
+What about mongomapper, I'd like to support it in future, but I have no
+experience in it, does anybody have interests to implement it? Feel free
+to contact me.
+
+Another big improvement in 4.0.0 is much better integration tests. If
+you check out the source code, you will see I separate different
+integration tests for activerecord 2, activerecord 3 and mongoid, I also
+add these integration tests to different Gemfiles, and ask travis to
+test all of them for bullet, see the [build result][4].
+
+If you have any problems to use bullet gem, feel free to mail me, tweet
+me or open an issue on github.
+
+[1]: https://github.com/flyerhzm/bullet
+[2]: http://mongoid.org/performance.html
+[3]: https://github.com/flyerhzm/mongoid-eager-loading
+[4]: http://travis-ci.org/#!/flyerhzm/bullet/builds/1283580