c# – 如何有效地使用大数据集中LINQ并行中的子句或选择

我有大约250,000条记录标记为Boss,每个Boss有2到10名职员.我每天都需要了解员工的详细信息.大约有1,000,000名员工.我正在使用 Linq获取每日工作人员的唯一列表.考虑以下C#LINQ和模型

void Main()
{

    List<Boss> BossList = new List<Boss>()
    {
        new Boss()
        {
            EmpID = 101,Name = "Harry",Department = "Development",Gender = "Male",Employees = new List<Person>()
            {
                new Person() {EmpID = 102,Name = "Peter",Gender = "Male"},new Person() {EmpID = 103,Name = "emma Watson",Gender = "Female"},}
        },new Boss()
        {
            EmpID = 104,Name = "Raj",Employees = new List<Person>()
                    {
                        new Person() {EmpID = 105,Name = "Kaliya",..... ~ 250,000 Records ......

    };

    List<Person> staffList = BossList
    .SelectMany(x =>
        new[] { new Person { Name = x.Name,Department = x.Department,Gender = x.Gender,EmpID = x.EmpID } }
        .Concat(x.Employees))
    .GroupBy(x => x.EmpID) //Group by employee ID
    .Select(g => g.First()) //And select a single instance for each unique employee
    .ToList();
}

public class Person
{
    public int EmpID { get; set; }
    public string Name { get; set; }
    public string Department { get; set; }
    public string Gender { get; set; }
}

public class Boss
{
    public int EmpID { get; set; }
    public string Name { get; set; }
    public string Department { get; set; }
    public string Gender { get; set; }
    public List<Person> Employees { get; set; }
}

在上面的LINQ中我得到了不同员工或员工名单,该列表包含超过1,000条记录.从获得的列表中我需要搜索“Raj”

staffList.Where(m => m.Name.ToLowerInvariant().Contains("Raj".ToLowerInvariant()));

对于此操作,获得结果需要3到5分钟.

我怎么能让它更有效率.请帮助我……

IEnumerable<Person> staff = BossList 
    .Concat(BossList
        .SelectMany(x => x.Employees)
    )
    .distinctBy(p => p.EmpId)
    .ToList()

public static IEnumerable<TSource> distinctBy<TSource,TKey>
    (this IEnumerable<TSource> source,Func<TSource,TKey> keySelector)
{
    var seenKeys = new HashSet<TKey>();
    foreach (TSource element in source)
    {
        if (seenKeys.Add(keySelector(element)))
        {
            yield return element;
        }
    }
}

staffList.Where(m => m.Name.Equals("Raj",StringComparison.InvariantCultureIgnoreCase));