iosobjective-ccore-datapersistent-storagewal

How to disable WAL journal mode


https://developer.apple.com/library/ios/releasenotes/DataManagement/WhatsNew_CoreData_iOS/

I am having trouble in disabling journal mode.

My code is:

static NSManagedObjectContext *managedObjectContext(){
static NSManagedObjectContext *context = nil;
if (context != nil) {
    return context;
}

NSString * const NSSQLitePragmasOption;

NSSQLitePragmasOption : @{ @"journal_mode" : @"DELETE" };

@autoreleasepool {
    context = [[NSManagedObjectContext alloc] init];
    
    NSPersistentStoreCoordinator *coordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:managedObjectModel()];
    [context setPersistentStoreCoordinator:coordinator];
    
    NSString *STORE_TYPE = NSSQLiteStoreType;

    NSString *path = @"ExerciseDB";
    NSURL *url = [NSURL fileURLWithPath:[path stringByAppendingPathExtension:@"sqlite"]];
 
    NSError *error;
    NSPersistentStore *newStore = [coordinator addPersistentStoreWithType:STORE_TYPE configuration:nil URL:url options:NSSQLitePragmasOption error:&error];
    
    if (newStore == nil) {
        NSLog(@"Store Configuration Failure %@", ([error localizedDescription] != nil) ? [error localizedDescription] : @"Unknown Error");
    }
}
return context;
}

How would I go about disabling journal mode WAL.

Thanks


Solution

  • To disable WAL mode, set the journal_mode to DELETE

    NSMutableDictionary *pragmaOptions = [NSMutableDictionary dictionary];
    [pragmaOptions setObject:@"DELETE" forKey:@"journal_mode"];
    
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, pragmaOptions, NSSQLitePragmasOption, nil];
    [_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:options error:&error]