ios - Sqlite or Core Data to update more then 50000 records -

i'm using coredata project. when api returns 54000 objects app need update, user has wait 2 hours. it's major problem current project , thinking use sqlite , not using coredata anymore update thousands of objects.

is right decision use sqlite or there suggestion coredata? can't decide. great. thank you.

here doing:

nsmanagedobjectcontext *privateobjectcontext = [appdelegate appdelegate].privatemanagedobjectcontext;     [privateobjectcontext performblock:^{        int = 1;       (nsdictionary *item in itemlist) {             i++;              [fetchrequest setpredicate:[nspredicate predicatewithformat:                                         @"itemid == %@",[item objectforkey:@"item_id"]                                         ]];             nserror *error;             nsmutablearray *inventories = [[nsmutablearray alloc]initwitharray:                                            [privateobjectcontext executefetchrequest:fetchrequest                                                                                error:&error]];             itemmanagedobject *itemmo;              if(inventories.count){                 itemmo = inventories.firstobject;             }else{                 itemmo = [nsentitydescription insertnewobjectforentityforname:@"itemobject"                                                        inmanagedobjectcontext:privateobjectcontext];             }             [itemmo preparewithdictionary:item];         }          nserror *error;         if (![privateobjectcontext save:&error]) {             completionhandler(no);         } } 

2 hours long. that's weird.

yet can massage code having core data less work. less work.

1. perform single fetch request instead of 54k fetch requests
2. don't call managed object property setter when property value not change, no object unnecessarily flagged dirty, , core data not have perform costly useless update of object when "save" method invoked.

this dramatically reduce amount of work performed core data, , performance of application.

the second point easy, verbose: compare each individual property values dictionary values before calling setters.

the first point requires algorithm change:

perform single fetch request, sorted id (with [nsfetchrequest setsortdescriptors:])

sort dictionaries id (with [nsarray sortedarray...])

synchronize 2 sorted lists (it paramount both lists sorted):

nsenumerator *itemmoenum = [itemmos objectenumerator]; nsenumerator *dicenum = [dictionaries objectenumerator]; itemmanagedobject *itemmo = [itemmoenum nextobject]; nsdictionary *itemdic = [dicenum nextobject];  while (itemdic) {     nscomparisonresult comparison = itemmo ? [itemdic[@"item_id"] compare:itemmo.itemid] : nsorderedascending;     switch (comparison) {         case nsorderedsame:             // id present in both lists: update             [itemmo preparewithdictionary:itemdic];              itemmo = [itemmoenum nextobject];             itemdic = [dicenum nextobject];             break;          case nsorderedascending: {             // id present in dictionaries: create             itemmo = [nsentitydescription insertnewobjectforentityforname:@"itemobject"                                           inmanagedobjectcontext:privateobjectcontext];             [itemmo preparewithdictionary:itemdic];              itemdic = [dicenum nextobject];         } break;          case nsordereddescending:             // id present in managed object: delete or nothing             itemmo = [itemmoenum nextobject];             break;     } }  while (itemmo) {     // id present in managed object: delete or nothing     itemmo = [itemmoenum nextobject]; } 

and save.

finally, maybe sqlite faster (see https://github.com/groue/grdb.swift/wiki/performance attempt @ comparing performance of core data sqlite libraries).

but sqlite won't turn slow algorithm fast one.