I'm having 2 entities CDChatConversation and CDMessage. CDConversation having to many relationship with messages. I want to fetch all conversation with sorting of lastMessage's datetime attribute which is kind of Date.

Currently I'm using following predicate and FetchRequest but I think this will take more time when I'm having more data.

func getChatConversationSorted() throws -> [CDChatConversation] {
    let fetchRequest: NSFetchRequest<CDMessage> = CDMessage.fetchRequest()
    let timePredicate = NSPredicate(format: "dateTime = conversation.messages.@max.dateTime")
    fetchRequest.predicate = timePredicate
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: #keyPath(CDMessage.dateTime), ascending: false)]
    let fetchedMessages = try context.fetch(fetchRequest)
    let fetchedConversations = fetchedMessages.compactMap({$0.conversation})
    return fetchedConversations
}

How can I directly predicate on CDChatConversation?