You may wonder what’s going on since we released Bugzilla 4.4rc1 on November 13. Well, very few bugs have been reported which seems to indicate that 4.4rc1 is pretty stable. But we also found that running some queries were very slow since Bugzilla 4.2. Bugzilla 4.2 got a major rewrite of its search code (Bugzilla::Search), where the focus was readability, maintainability and the removal of some hacks, but this new code had some severe performance impact for some queries, especially those involving subselects in MySQL. That’s why several bugs related to performance have been filed since we released 4.4rc1 and we decided that they were critical enough to fix them in the 4.4 branch rather than waiting another year to include them in Bugzilla 5.0 only. As it’s unclear if these recent changes can have negative impact on some queries, or break some other ones, we decided that a 2nd release candidate was necessary to give admins and developers some time to test the new code and give us feedback before 4.4 final. There is no ETA for 4.4rc2 yet, but it will probably be somewhere in January 2013.
If you have some queries which you consider as being very slow, I would be interested in hearing you about them: which criteria did you use, which columns are displayed in buglists, which Bugzilla installation did you use for your testing, are you logged in or logged out, etc…? Please don’t run your queries on Bugzilla 3.x or older. I’m really not interested in such old installations (and the code changed too much anyway with what we have in 4.4). In my own testing, I found that some queries which were previously timing out now run in a few seconds only. Of course, the time taken to execute these queries highly depends on the data you have in your DB and so only relative timing matters.