如何提高核心数据性能?

我的应用程序有一个uisearchbar,允许用户输入搜索关键字。每个按键都执行一个核心数据查询,以便在搜索栏中的文本更改时显示结果。

问题是搜索栏的击键滞后得很厉害…当然是因为提取速度慢。有什么办法提高性能吗?

我的核心数据由包含1000个对象的sqlite数据存储进行备份。

// searchKeyword is the string appears in UISearchBar
// Both title and author may contain several words so I can't use BEGINSWITH
NSPredicate* predicate = [NSPredicate predicateWithFormat:@"(author CONTAINS[c] %@) OR (title CONTAINS[c] %@)", searchKeyword, searchKeyword];

NSEntityDescription* entity = [NSEntityDescription entityForName:@"Book" inManagedObjectContext:managedObjectContext];

NSFetchRequest* request = [[NSFetchRequest alloc] init];
[request setEntity:entity];
[request setPredicate:predicate];
[request setFetchLimit:10];

NSSortDescriptor* sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"title" ascending:YES];
NSArray* sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[request setSortDescriptors:sortDescriptors];

[sortDescriptor release];
[sortDescriptors release];

execute request and fetch the results
fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request
                                managedObjectContext:managedObjectContext
                                sectionNameKeyPath:nil
                                cacheName:nil];
NSError* error = nil;
BOOL success = [fetchedResultsController performFetch:&error];
[request release];