When we use CoreData , UserDefaults, Keychain

Question

iOS has more than one local databases like CoreData, Keychain, UserDefault. All 3 databases do the same thing, Saving, Updating, Selecting, etc. Are there any different between them, like security, memory or speed? When using (CoreData, UserDefaults, Keychain) more powerful than others?

Each have completely different uses. Please read the documentation for each and then update your question with more details about what you need clarified. — rmaddy, Jan 25 '19 at 22:57

score 6 · Answer 1 · edited Jan 25 '19 at 22:55

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Not everything , but in short

Userdefaults : is used for saving settings data. It's not to be used for temporary data across viewControllers. It's the fastest as it's plist file or a dictionary when it comes to running state of the app
CoreData : is a relational database used for large data storage , creates models automatically from simple UI and it's a sqlite-based
Keychain : is the most secure and always used for sensitive data like tokens , passwords etc. But it's also the slowest one as it's a c - wrapper.

edited Jan 25 '19 at 22:55

mfaani

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answered Jan 25 '19 at 22:43

Shehata Gamal

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Thanks to answer me . I used them randomly. Now I have some idea about them. – Omer Tekbiyik Jan 25 '19 at 22:47
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Core Data is not specifically a database or backed by SQLite. That's just the most common use. – rmaddy Jan 25 '19 at 22:59
CoreData is not a database ?? it is even it's UI supports that it's a relational also – Shehata Gamal Jan 25 '19 at 23:02
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Core Data is for managing object graphs. It support 4 possible persistence models. The SQLite database is just one of the 4 options. – rmaddy Jan 25 '19 at 23:21
Core data is an object graph mapper. Just because Core Data is a data persistent doesn't mean that it is a database – Aji Saputra Raka Siwi Jul 21 '21 at 07:16

score 1 · Answer 2 · answered Jan 25 '19 at 22:37

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NSCoding/NSKeyedArchiver vs. Core Data doesn't directly answer your question. But it's very helpful. Long story short: Core data is a pain in the neck but when it comes to modeling, querying, traversing and persisting complex object graphs, there is no substitute for Core Data. Core Data is a big hammer, but not every problem is a nail—much less a sufficiently large nail.

KeyChain is more like a vault. You store small limited information in it e.g. password. You don't store the entire database in it. It acts like a gatekeeper "Can this user open the app? Yes? Ok let's open up our data base and show core data entries..."

UserDefaults are like the last page a user was at. You may store a single custom object, but don't store a big record of it.

answered Jan 25 '19 at 22:37

mfaani

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Thanks to answer me . I used them randomly. Now I have some idea about them. – Omer Tekbiyik Jan 25 '19 at 22:47
the userdefault shouldn't be used to store objects at all even if small – Shehata Gamal Jan 25 '19 at 22:48
@Sh_Khan I don't get you. Can you clarify? I'm asking because I also see: [`set(_:forKey:)`](https://developer.apple.com/documentation/foundation/userdefaults/1414067-set) – mfaani Jan 25 '19 at 22:50
@Honey this used for data like `[1,2,"awea",1.22]` what i meant is that it's not for a custom object – Shehata Gamal Jan 25 '19 at 22:58

When we use CoreData , UserDefaults, Keychain

2 Answers2