How to disable WAL journal mode

Question

https://developer.apple.com/library/ios/releasenotes/DataManagement/WhatsNew_CoreData_iOS/

I am having trouble in disabling journal mode.

My code is:

Answer 1

From Apple Technical Documentation: Technical Q&A QA1809

NSDictionary *options = @{NSSQLitePragmasOption:@{@"journal_mode":@"DELETE"}};
if (! [persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
                                            configuration:nil
                                            URL:storeURL
                                            options:options
                                            error:&error]) {
    // error handling.
}

Edit 2020:

SwiftUI + iOS 14 (Xcode 12 beta 6)

When you create a new project with SwiftUI and check CoreData template, your new project has this code in Persistence.swift file:

struct PersistenceController {
    static let shared = PersistenceController()

    //...

    let container: NSPersistentContainer

    init(inMemory: Bool = false) {
        container = NSPersistentContainer(name: "db_name")
        if inMemory {
            container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
        }
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                //...
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
    }
}

Now, you can add the following block of code after init container (container = NSPersistentContainer(name: "db_name"))

if let url = container.persistentStoreDescriptions.first?.url {
    let storeDescription = NSPersistentStoreDescription(url: url)
    storeDescription.setValue("DELETE" as NSObject, forPragmaNamed: "journal_mode")
    container.persistentStoreDescriptions = [storeDescription]
}