问大型sql选择的超时

EN

List<int> klienter = FundneKlienter.Keys.ToList();

if (klienter.Count > 0)
{
    Dictionary<int, String> klientNavne = new Dictionary<int, string>(klienter.Count);
    String sql = "SELECT [0],[1] FROM [Tabel] WHERE [0] IN " + klienter.ToSqlList();

    using (SqlCommand cmd = new SqlCommand(sql, _connection))
    using (SqlDataReader sr = cmd.ExecuteReader())
        if (sr.HasRows)
            while (sr.Read())
                klientNavne.Add(int.Parse(sr["0"].ToString()), sr["1"].ToString());