Brtdku

I want to disable the journal mode in my core data app.
This is the code:

- (NSPersistentContainer *)persistentContainer {

// The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it.

@synchronized (self) {

    if (_persistentContainer == nil) {

        _persistentContainer = [[NSPersistentContainer alloc] initWithName:@"My_App"];



        NSURL *url = [[self applicationFilesDirectory] URLByAppendingPathComponent:@"My_App.sqlite"];

        NSPersistentStoreDescription *description=[[NSPersistentStoreDescription alloc]initWithURL:url];

        NSMutableDictionary *pragmaOptions=[NSMutableDictionary dictionary];

        [pragmaOptions setObject:@"DELETE" forKey:@"journal_mode"];

        [description setOption:pragmaOptions forKey:@"NSQlitePragmaOptions"];

        _persistentContainer.persistentStoreDescriptions=@[description];

        [_persistentContainer loadPersistentStoresWithCompletionHandler:^(NSPersistentStoreDescription *storeDescription, NSError *error) {

            if (error != nil) {

                // Replace this implementation with code to handle the error appropriately.

                // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.



                /*

                 Typical reasons for an error here include:

                 * The parent directory does not exist, cannot be created, or disallows writing.

                 * The persistent store is not accessible, due to permissions or data protection when the device is locked.

                 * The device is out of space.

                 * The store could not be migrated to the current model version.

                 Check the error message to determine what the actual problem was.

                */

                NSLog(@"Unresolved error %@, %@", error, error.userInfo);

                abort();

            }

        }];

    }

}



return _persistentContainer;}

I also verified with this:

NSArray *descriptionArray=[_persistentContainer persistentStoreDescriptions];

NSPersistentStoreDescription * description=[descriptionArray objectAtIndex:0];

NSLog(@"%@",description.options);

and the result of NSLog is:

{

NSInferMappingModelAutomaticallyOption = 1;

NSMigratePersistentStoresAutomaticallyOption = 1;

NSQlitePragmaOptions =     {

    "journal_mode" = DELETE;

};

but when I restart my app I always find in the application directory all the three file My_App.sqlite, My_App.sqlite-shm and My_App.sqlite-wal.

Why doesn't it work?