ios - How to update all records as quickly as possible? -

i need update records same value. , don't want iteration on objects since takes 2 seconds on 2000 objects. have users locally , receive users id's server. want set property 'requested' false except users return server-

how done (which totally wrong!):

iterating thru users (about 2000 of them) , correcting requested value.

nsfetchrequest * allusers = [[nsfetchrequest alloc] init]; [allusers setentity:[nsentitydescription entityforname:@"user" inmanagedobjectcontext:context]]; nsarray *users = [context executefetchrequest:allusers error:&error];  nsarray *userids = [json objectforkey:@"users_ids"]; (user *user in users) {     if ([userids containsobject:user.userid]) {         user.requested = [nsnumber numberwithbool:yes];     } else {         user.requested = [nsnumber numberwithbool:no];     }     user.requested = [nsnumber numberwithbool:no]; } [context save:nil]; 

my idea how it:

set requested=false every object sql-like 1 statement. going thru id's returned server (20 on average) , setting requested=true those.

// update users set requested = false 1=1  nsarray *userids = [json objectforkey:@"users_ids"]; (int = 0; < [userids count]; i++) {     user *user = [user userwithserverid:[userids[i] integervalue] usingmanagedobjectcontext:context];     user.requested = [nsnumber numberwithbool:yes]; } [context save:nil]; 

so how update records 1 "query" ? or have better idea how implement (more performance efficient way of doing iteration perhaps) ?

putting in background thread solution (perhaps), still optimise first before putting in background thread.

thank you!

you still have fetch objects can in 1 line.

[[fetchedresultscontroller fetchedobjects] makeobjectsperformselector:@selector(setyourvalue:) withobject:[nsnumber numberwithbool:yes]]; 

or cycle array

nsarray *objects = [context executefetchrequest:allrequest error:&error]; [objects setvalue:[nsnumber numberwithbool:yes] forkey:@"user_ids"]; //now save changes back. [context save:&error];