I would use CLucene for this. It isn't as easy to use as CoreData (it is written in C++, so you'll need some Objective-C++ as a shim at a minimum), but it is powerful and VERY fast.
-Heath >From my iTouch4 On Jul 14, 2011, at 1:17 PM, Indragie Karunaratne <cocoa...@indragie.com> wrote: > Hi guys, > > I'm working on a search feature in one of my Core Data based apps and I'm > trying to gather everyone's tips on search optimization to get it as fast as > I possibly can. The search needs to be fast enough that it can deliver > near-instantaneous results for database of 20,000+ objects. > > What I've done so far (as far as optimization goes) > - Implemented the technique shown in WWDC 2010 session 137, creating a > keyword entity and creating a to-many relationship from my main object > entities to it. The keyword entity's 'name' attribute is indexed, and > keywords are created during the initial import procedure by splitting apart > relevant strings in the main entities and normalizing them (stripped of case > and diacritics) > - Using >= and < binary comparators instead of BEGINSWITH, etc. My predicate > format is: SUBQUERY(keywords, $keyword, ($keyword.name >= $LB) AND > ($keyword.name < $UB)).@count != 0 > > Where $LB is the lower bounds string and $UB is upper bounds. I create a > compound AND predicate using this format and the array of search terms. > > Right now, I'm executing a fetch once (when the user types the first letter) > using a fetch batch size of about 20, and then narrowing down the search > results using NSArray's -filteredArrayUsingPredicate method as they continue > typing. I also prefetch the "keywords" relationship because this is used to > filter. The part that takes up the most time, obviously, is the initial > fetch. There's a noticeable delay of ~1-2s on a library of around 15,000 > objects. Time profiling shows that it is indeed the fetch that is causing the > delay: > > http://cl.ly/3a1b2022452M2V323f2H > > One other thing thats worth noting is that I have to fetch multiple entities > for the results. All of the entities have a "ranking" attribute, but I can't > fetch more than one at once so I'm forced to fetch them separately, combine > them into a single array, and then sort manually via > -sortedArrayUsingDescriptors. > > Any tips on how to speed this up would be greatly > appreciated._______________________________________________ > > 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/heath.borders%40gmail.com > > This email sent to heath.bord...@gmail.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
