Is swiftData just not useable with large data?

Is SwiftData not designed for large datasets? How to create many instances of my Data Model?

I have a loop where I iterate over a CSV file of 30k+ lines. Totalling around 230k elements. I intend to save this data into SwiftData. However it takes around 90 seconds. In previous versions of my app I was using coreData. Then it took just 3 seconds. So after much investigation I have concluded the delay comes from creating instances of the Data Model. To Test this I have :

• Removed any saves into SwiftData. So only creation of the Model Object occurs.

• Created an exact copy of the SwiftData Model class but admitted the @Model macro

• set isAutosaveEnabled to false

When I run my loop with the copy class it takes 3 seconds. So It must be creating the SwiftData model instances that causes the *30 delay.

The code using swiftData @Model. This loop takes 90+ seconds to complete

    class TimetableData {
     
        var arrivalTime : Int = 0
        var departureTime: Int = 0
        var departureRoute : Int = 0
        var directionOfTravel : Int = 0
        var dutyNumber : Int = 0
        var facilityIdentifier : String = ""
        var locationType : String = ""
        var mode : String = ""
        var nonStopStatus : Int = 0
        var recordIdentifier : String = ""
        var timetableIdentifier : Int = 0
        var trainNumber : String = ""
        var tripNumber : Int = 0
        var tripStartSite : String = ""
        var uniqueLocationCode : String = ""
        
        init(arrivalTime: Int = 0, departureTime: Int = 0, departureRoute: Int = 0, directionOfTravel: Int = 0, dutyNumber: Int = 0, facilityIdentifier: String = "", locationType: String = "", mode: String = "", nonStopStatus: Int = 0, recordIdentifier: String = "", timetableIdentifier: Int = 0, trainNumber: String = "", tripNumber: Int = 0, tripStartSite: String = "", uniqueLocationCode: String = "") {
        
            self.name = name
            self.arrivalTime = arrivalTime
            self.departureTime = departureTime
            self.departureRoute = departureRoute
            self.directionOfTravel = directionOfTravel
            self.dutyNumber = dutyNumber
            self.facilityIdentifier = facilityIdentifier
            self.locationType = locationType
            self.mode = mode
            self.nonStopStatus = nonStopStatus
            self.recordIdentifier = recordIdentifier
            self.timetableIdentifier = timetableIdentifier
            self.trainNumber = trainNumber
            self.tripNumber = tripNumber
            self.tripStartSite = tripStartSite
            self.uniqueLocationCode = uniqueLocationCode
        }
        
    }
 
 
for line in CSVFile {  
 
var columnValue = line.components(separatedBy: ",")
 
let timeTableDataEntry  = TimetableData (
                     
                            arrivalTime: Int(columnValue[0])!,
                            departureTime: Int(columnValue[1])!,
                            departureRoute: Int(columnValue[2])!,
                            directionOfTravel: Int(columnValue[3])!,
                            dutyNumber: Int(columnValue[4])!,
                            facilityIdentifier: columnValue[5],
                            locationType: columnValue[6],
                            mode: columnValue[7],
                            nonStopStatus: Int(columnValue[8])!,
                            recordIdentifier:  columnValue[9],
                            timetableIdentifier: Int(columnValue[10])!,
                            trainNumber: columnValue[11],
                            tripNumber: Int(columnValue[12])!,
                            tripStartSite: columnValue[13],
                            uniqueLocationCode:columnValue[14]
                        )
 
}
 

Then The exact same code but omitting the @Model takes around just 3 second.

   class TimetableDataForTesting {
 
        var arrivalTime : Int = 0
        var departureTime: Int = 0
        var departureRoute : Int = 0
        var directionOfTravel : Int = 0
        var dutyNumber : Int = 0
        var facilityIdentifier : String = ""
        var locationType : String = ""
        var mode : String = ""
        var nonStopStatus : Int = 0
        var recordIdentifier : String = ""
        var timetableIdentifier : Int = 0
        var trainNumber : String = ""
        var tripNumber : Int = 0
        var tripStartSite : String = ""
        var uniqueLocationCode : String = ""
 
        init(arrivalTime: Int = 0, departureTime: Int = 0, departureRoute: Int = 0, directionOfTravel: Int = 0, dutyNumber: Int = 0, facilityIdentifier: String = "", locationType: String = "", mode: String = "", nonStopStatus: Int = 0, recordIdentifier: String = "", timetableIdentifier: Int = 0, trainNumber: String = "", tripNumber: Int = 0, tripStartSite: String = "", uniqueLocationCode: String = "") {
 
            self.name = name
            self.arrivalTime = arrivalTime
            self.departureTime = departureTime
            self.departureRoute = departureRoute
            self.directionOfTravel = directionOfTravel
            self.dutyNumber = dutyNumber
            self.facilityIdentifier = facilityIdentifier
            self.locationType = locationType
            self.mode = mode
            self.nonStopStatus = nonStopStatus
            self.recordIdentifier = recordIdentifier
            self.timetableIdentifier = timetableIdentifier
            self.trainNumber = trainNumber
            self.tripNumber = tripNumber
            self.tripStartSite = tripStartSite
            self.uniqueLocationCode = uniqueLocationCode
        }
 
    }
 
 
for line in CSVFile {  
 
var columnValue = line.components(separatedBy: ",")
 
let timeTableDataEntry  = TimetableDataForTesting (
 
                            arrivalTime: Int(columnValue[0])!,
                            departureTime: Int(columnValue[1])!,
                            departureRoute: Int(columnValue[2])!,
                            directionOfTravel: Int(columnValue[3])!,
                            dutyNumber: Int(columnValue[4])!,
                            facilityIdentifier: columnValue[5],
                            locationType: columnValue[6],
                            mode: columnValue[7],
                            nonStopStatus: Int(columnValue[8])!,
                            recordIdentifier:  columnValue[9],
                            timetableIdentifier: Int(columnValue[10])!,
                            trainNumber: columnValue[11],
                            tripNumber: Int(columnValue[12])!,
                            tripStartSite: columnValue[13],
                            uniqueLocationCode:columnValue[14]
                        )
 
}