> On Fri, Apr 22, 2011 at 9:22 PM, Shawn Milochik <sh...@milochik.com> wrote: >> >> This was mentioned in Eric Florenzano's talk at DjangoCon 2010. Each >> version has gotten slower. >> >> I haven't heard anything about the cause or plans to fix this, though. >> If you've got a good test suite you can always use tools like Python's >> profile module to track down slowdowns in your Django code and >> contribute that knowledge to the developers' list. >>
On Sat, Apr 23, 2011 at 11:26 AM, Peter Portante <peter.a.porta...@gmail.com> wrote: > Is there a plan in place to address this? No - there isn't a plan to address this, because it isn't clear what "this" is. While it is known that there has been a slowdown between versions, that slowdown has been accompanied by a massive increase in functionality -- for example, the 1.1->1.2 transition introduced support for multiple databases. To the best of my knowledge, the performance slowdown highlighted by Eric at Djangocon was relatively small - 5-10%, not on the order of 30-50% slowdown. This matches with my personal experience of upgrading. There are two performance issues in database operations that I'm aware of that people commonly point to. Firstly -- deep cloning of query sets. Cloning a queryset is an expensive operation, and if you are making extensive use of operations that clone (e.g., very long chains of complex filters) you may see performance issues. This isn't something that can be easily avoided -- in order to preserve the API guarantees of a query set, deep cloning is required. Secondly, the backwards compatibility infrastructure introduced in order to support multiple databases. In order to guarantee backwards compatibility, the value preparation methods on fields needed to use some moderately expensive introspection methods. However because these methods were introduced for 1.2, and we're currently preparing 1.4, these introspection methods have just been removed from trunk. Beyond these two issues -- we're always interested in improving performance, so if you can identify a specific performance issue, we're happy to look at it. The more evidence you can provide (profile runs, sample queries that are observably slower, and so on), the easier it will be to address these problems. Yours, Russ Magee %-) -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
