Skip to main content

The differences between Core Data and a Database



DatabaseCore Data
Primary function is storing and fetching dataPrimary function is graph management (although reading and writing to disk is an important supporting feature)
Operates on data stored on disk (or minimally and incrementally loaded)Operates on objects stored in memory (although they can be lazily loaded from disk)
Stores "dumb" dataWorks with fully-fledged objects that self-manage a lot of their behavior and can be subclassed and customized for further behaviors
Can be transactional, thread-safe, multi-userNon-transactional, single threaded, single user (unless you create an entire abstraction around Core Data which provides these things)
Can drop tables and edit data without loading into memoryOnly operates in memory
Perpetually saved to disk (and often crash resilient)Requires a save process
Can be slow to create millions of new rowsCan create millions of new objects in-memory very quickly (although saving these objects will be slow)
Offers data constraints like "unique" keysLeaves data constraints to the business logic side of the program

Comments

Popular posts from this blog

Understanding of Size Classes?

Size Classes are an abstraction of how a device should be categorized depending on its screen dimensions. Apple defined two categorizations for both vertical and horizontal sizes called “Regular” and “Compact”. The former specifies a big space, while the latter specifies a small” space. How big or small exactly? Here, “big” and “small” are not intended to be measured in inches. iOS Size Classes Apple has introduced many devices like iPhone, iPad with different screen sizes and resolution. Also after iOS 8 apple has supported multitasking in iPad. So for the developers to develop a common or single UI for all the devices apple has introduced the concept of an adaptive layout by combining auto layout and size classes. What is adaptive layout: The adaptive layout is a method of building the apps based on the size and characteristics of the container instead of a targeting a particular device. We can create a single layout to work on all...

What Is a Closure?

Closures are self contained chunks of code that can be passed around and used in your code. Closures can capture and store references to any constants or variables from the context in which they are defined. This is know as closing over those variables, hence the name closures. Closures are use intensively in the Cocoa frameworks – which are used to develop iOS or Mac applications. Functions are a special kind of closures. There are three kinds of closures: global functions  – they have a name and cannot capture any values nested functions  – they have a name and can capture values from their enclosing functions closure expressions  – they don’t have a name and can capture values from their context The thing to keep in mind for the moment is that you already have an intuition about closures. They are almost the same as functions but don’t necessarily have a name. // a closure that has no parameters and return a String var hello: () -> ( String ) = { ...