> Date: Fri, 16 Jan 2009 13:03:24 +0100 > From: Matteo Manferdini <mat.maili...@gmail.com> > Subject: Long load time of managed object context > > I'm testing performance in my application, to see how it behaves with > a big load of data inside of it. My application is core data based and > uses array controllers in entity mode to fetch data. > > What I discovered is that my app fetched all the managed objects > present in core data, so I set the fetch predicate of array > controllers at startup. This reduced dramatically the number of > objects fetched. The problem though is that my app still takes a lot > of time to start when is full of data. > > I ran the app within instruments, and the core data fetches instrument > confirms that this is not the problem (my app fetches only 20-30 > objects when starts). But running it under Shark I can see that for > 4-5 seconds after startup the only call on the stack is to the app > managed object context. So I think it has something to do with > interaction between managed object context and data stored, even if I > don't fetch all the data. If I empty the app or leave little data > inside of it, it starts very quickly. > > Does somebody know why this happens? Am I missing something obvious? > Why does it take so much to the managed object context to load if I > only fetch few objects? I always read that core data scales well and > the programming guide states that 10.000 objects are not much for core > data, but in my app it makes a big difference, so I'm wondering where > I am wrong.
You don't say what format you're using, but if you're using XML, the entire XML file has to be loaded and parsed, even before you fetch any objects. m. -- matt neuburg, phd = m...@tidbits.com, http://www.tidbits.com/matt/ pantes anthropoi tou eidenai oregontai phusei Among the 2007 MacTech Top 25, http://tinyurl.com/2rh4pf AppleScript: the Definitive Guide, http://tinyurl.com/2ouo3b Take Control of Customizing Leopard, http://tinyurl.com/2t9629 TidBITS, Mac news and reviews since 1990, http://www.tidbits.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
