List <>和查詢之間的搜索性能

Question

我使用SDK從Staging到Microsoft Dynamic CRM進行數據遷移，但我對速度性能有疑問。

我在使用List<>和SQL Query搜索現有數據的性能之間存在一些疑問。

我的問題是

1. 在List<>搜索現有數據和Query from DataBase逐行Query from DataBase比較快（ 在列表中約有100,000個對象或在數據庫中有100,000個記錄 ）。如果使用此方法，請立即連接數據庫。
2. 我認為數據庫使用index應該比在對象列表中搜索更快？ 但是如果我使用查詢來搜索現有數據（100,000條記錄），則必須打開並查詢100,000次

謝謝。

Answer 1

示例（顯然，您想對此進行優化-這只是一個想法）：

private Dictionary<string, HashSet<person>> peopleList = new Dictionary<string, HashSet<person>>();
    public void loadPeople()

    {
        List<person> people = new List<person>();
        people.Add(new person() { firstName = "Shirley", lastName = "Kotarski", age = 45 });
        people.Add(new person() { firstName = "Bob", lastName = "Smith", age = 24 });
        people.Add(new person() { firstName = "Bill", lastName = "Jones", age = 32 });
        people.Add(new person() { firstName = "Jim", lastName = "Hostettler", age = 19 });
        people.Add(new person() { firstName = "Ralph", lastName = "Billings", age = 27 });
        people.Add(new person() { firstName = "Eddir", lastName = "Johnson", age = 58 });
        for (int i = 65; i < 91; i++)
        {//Partitions based on first letter of first name
            string charI = ((char)i).ToString();
            string key = charI;
            peopleList.Add(key, new HashSet<person>(people.Where(p => p.firstName.Substring(0, 1) == charI).ToArray()));

        }
    }
    public void processListOfPeople()
    {
        for (int i = 65; i < 91; i++)
        {
            string charI = ((char)i).ToString();
            string key = charI;
            List<person> people = peopleList[key].ToList();
         }
    }
    public person lookupPerson(string firstName)
    {
        person p = new so_Win.person();
        string key = firstName.Substring(0, 1);
        return peopleList[key].Where(m => m.firstName == firstName).ToArray()[0];
    }