Technology Overview

This article describes the basic features provided by Core Data, and reasons why it might be appropriate for you to adopt the technology.

Core Data Features

The Core Data framework provides generalized and automated solutions to common tasks associated with object life-cycle and object graph management, including persistence. Its features include:

Why Should You Use Core Data?

There are a number of reasons why it may be appropriate for you to use Core Data. One of the simplest metrics is that, with Core Data, the amount of code you write to support the model layer of your application is typically 50% to 70% smaller as measured by lines of code. This is primarily due to the features listed above—the features Core Data provides are features you don’t have to implement yourself. Moreover they’re features you don’t have to test yourself, and in particular you don’t have to optimize yourself.

Core Data has a mature code base whose quality is maintained through unit tests, and is used daily by millions of customers in a wide variety of applications. The framework has been highly optimized over several releases. It takes advantage of information provided in the model and runtime features not typically employed in application-level code. Moreover, in addition to providing excellent security and error-handling, it offers best memory scalability of any competing solution. Put another way: you could spend a long time carefully crafting your own solution optimized for a particular problem domain, and not gain any performance advantage over what Core Data offers for free for any application.

In addition to the benefits of the framework itself, Core Data integrates well with the OS X tool chain. The model design tools allow you to create your schema graphically, quickly and easily. You can use templates in the Instruments application to measure Core Data’s performance, and to debug various problems. On OS X desktop, Core Data also integrates with Interface Builder to allow you to create user interfaces from your model. These aspects help to further shorten your application design, implementation, and debugging cycles.

What Core Data Is Not

Having given an overview of what Core Data is and does, and why it may be useful, it is also useful to correct some common misperceptions and state what it is not.