dispatch_async
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, (unsigned long)NULL), ^(void) { [self getResultSetFromDB:docids]; });
iOS, Android, Unity3D Education blog,
http://iphonedevsdk.com/forum/iphone-sdk-development/14403-nstimer-examples.html
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, (unsigned long)NULL), ^(void) { [self getResultSetFromDB:docids]; });