How should I handle the initialization of a prepopulated database ?

[leonardkrief]

Hi all
~2 years experienced dev, new to Swift and GRDB

I am trying to setup a GRDB stack onto my app
My app is a dictionnary that will rely on a static database (basically all the words and translations) that will weigh ~200MB

I tried to follow the best practices as shown in the Demo Apps, and I ended up with an AppDatabase class that I call at the launch of my app and that handles the initialization of my database (run migrations + populates it). But it seems to me that it always run the migrations + the populateDb function at the launch of the app. This is not what I expect as it will take a lot of time for my app to open everytime...
I guess I could also preload an already existing database, but I am not sure...

Would I still be able to rely on the GRDB associationRelationships like hasMany, belongsTo like in my examples below ?
Could you give me the best practice to handle such matter ?

Here are my files that I simplified for this example, my database schema is way bigger and complex than that:

//
//  Migration_01_CreateTables.swift
//  GRDBPlayground
//
//  Created by Léos on 28/07/2024.
//

import GRDB

struct Migration_01_CreateTables {
    static func performMigration(migrator: inout DatabaseMigrator) {
        migrator.registerMigration("CreateTables") { db in
            // Create wordboxes table
            try db.create(table: "wordboxes") { t in
                t.autoIncrementedPrimaryKey("id")
                t.column("name", .text).notNull()
            }
            
            // Create translations table
            try db.create(table: "translations") { t in
                t.autoIncrementedPrimaryKey("id")
                t.column("wordboxID", .integer).notNull().references("wordboxes")
                t.column("text", .text).notNull()
            }
        }
    }
}

//
//  models.swift
//  GRDBPlayground
//
//  Created by Léos on 27/07/2024.
//
import Foundation
import GRDB

enum Language: String {
    case english = "en"
    case french = "fr"
}

struct Translation: Codable {
    var id: Int64?
    var wordboxID: Int64?
    var text: String
}

extension Translation: FetchableRecord, MutablePersistableRecord {
    static var databaseTableName: String {
        return "translations"
    }
    
    enum Columns: String, ColumnExpression {
        case id, wordboxID, text
    }
    
    static let wordbox = belongsTo(WordBox.self)
    var wordbox: QueryInterfaceRequest<WordBox> {
        return request(for: Translation.wordbox)
    }
    
    mutating func didInsert(with rowID: Int64, for column: String?) {
        id = rowID
    }
}

struct WordBox: Codable {
    var id: Int64?
    var name: String
}

extension WordBox: FetchableRecord, MutablePersistableRecord {
    static var databaseTableName: String {
        return "wordboxes"
    }
    
    enum Columns: String, ColumnExpression {
        case id, name
    }
    
    static let translations = hasMany(Translation.self)
    var translations: QueryInterfaceRequest<Translation> {
        return request(for: WordBox.translations)
    }
    
    mutating func didInsert(with rowID: Int64, for column: String?) {
        id = rowID
    }
}

//
//  AppDatabase.swift
//  GRDBPlayground
//
//  Created by Léos on 27/07/2024.
//

import Foundation
import GRDB
import os.log

struct AppDatabase {
    private let dbWriter: any DatabaseWriter
    
    init(_ dbWriter: any DatabaseWriter) throws {
        self.dbWriter = dbWriter
        try migrator.migrate(dbWriter)
    }
    
    private static let sqlLogger = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "SQL")
    
    public static func makeConfiguration(_ base: Configuration = Configuration()) -> Configuration {
        var config = base
        
        if ProcessInfo.processInfo.environment["SQL_TRACE"] != nil {
            config.prepareDatabase { db in
                db.trace {
                    os_log("%{public}@", log: sqlLogger, type: .debug, String(describing: $0))
                }
            }
        }
        
#if DEBUG
        config.publicStatementArguments = true
#endif
        
        return config
    }
    
    private var migrator: DatabaseMigrator {
        var migrator = DatabaseMigrator()
        
#if DEBUG
        migrator.eraseDatabaseOnSchemaChange = true
#endif
        
        // Register migrations
        Migration_01_CreateTables.performMigration(migrator: &migrator)
        
        return migrator
    }
}

extension AppDatabase {
    static let shared = makeShared()
    
    private static func makeShared() -> AppDatabase {
        do {
            let fileManager = FileManager.default
            let appSupportURL = try fileManager.url(
                for: .applicationSupportDirectory, in: .userDomainMask,
                appropriateFor: nil, create: true)
            let directoryURL = appSupportURL.appendingPathComponent("Database", isDirectory: true)
            try fileManager.createDirectory(at: directoryURL, withIntermediateDirectories: true)
            
            let databaseURL = directoryURL.appendingPathComponent("db.sqlite")
            NSLog("Database stored at \(databaseURL.path)")
            let dbPool = try DatabasePool(
                path: databaseURL.path,
                configuration: AppDatabase.makeConfiguration()
            )
            
            let appDatabase = try AppDatabase(dbPool)
            
            // Populate the database if it is empty
//            try appDatabase.populate()
            
            return appDatabase
        } catch {
            fatalError("Unresolved error \(error)")
        }
    }
}

extension AppDatabase {
    var reader: DatabaseReader {
        dbWriter
    }
}

//
//  GRDBPlaygroundApp.swift
//  GRDBPlayground
//
//  Created by Léos on 27/07/2024.
//

import SwiftUI

@main
struct GRDBPlaygroundApp: App {
    init() {
        // Initialize the shared database instance
        _ = AppDatabase.shared
    }
    
    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(\.appDatabase, AppDatabase.shared)
        }
    }
}

struct AppDatabaseKey: EnvironmentKey {
    static let defaultValue: AppDatabase = AppDatabase.shared
}

extension EnvironmentValues {
    var appDatabase: AppDatabase {
        get { self[AppDatabaseKey.self] }
        set { self[AppDatabaseKey.self] = newValue }
    }
}