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Comment by trinix912 | Hacker News Reader

It’d be interesting to see a performance comparison of SwiftData vs. (objc?) CoreData vs. plain XML for large datasets. I recall plain XMLs being faster than CoreData a few years ago in certain scenarios.

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“Combining Core Data’s proven persistence technology and Swift’s modern concurrency features, SwiftData enables you to add persistence to your app quickly”

Isn't SwiftData mostly a wrapper around CoreData?

Most definitely

Then there probably won't be a difference in performance

There certainly could be. SwiftData @Models aren't subclasses of NSManagedObject, and don't have to use the Objective-C runtime for dispatch, or the KVC-style property accessors that Core Data uses.

The fact that it is built atop Core Data's persistent stores, cloud sync, etc. doesn't mean that it's a fascade in front of the Objective-C APIs.

It just makes it easier to use - meaning less glue code. Making CoreData Swift + SwiftUI native approach. Where currently you'd have to make a Core Data class wrapped by a @Observable Class.

It is a good addition. CoreData, is ok, but is not really used from serous apps. At least, none of the large ones that I have worked on.

Either use flat files (serialized json) to save and restore state, or just Sqlite directly.

Super interested to understand more of this - I've worked on lots of serious apps, but not more than the scale of "banking app with ~1m users and 6 iOS devs"

And do you mind telling what did those apps use? CoreData, SQLite, json files. Also do "serious" apps use Firebase anymore?

think about apps that have billions of users, they build their own wrappers around sqlite.

they also have their own version of firebase. firebase is the open source version of what google uses inside. sometimes big tech open sources parts of their technology (if its coded nice to dissect).

https://engineering.fb.com/2023/02/06/ios/facebook-ios-app-a...

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