{ "iisSettings": { "windowsAuthentication": false, "anonymousAuthentication": true, "iisExpress": { "applicationUrl": "http://localhost:55556/", "sslPort": 0 } }

I am new to C# and am using asp.net core 2.0 on my mac . I have a simple code that gets data from the database and just output it to the browser . I am doing stress testing and simulating how the systems handle 100 requests. The first request takes 2.5 seconds and the 100th request takes a whopping 13 seconds. I know that it is my code because I have the same exact query done in Golang to the same database and the first request takes 47 ms and the 100th request takes 14 ms . The SQL code just returns Json in string format from the database which is postgres . I am trying this now that way I don't get any surprises later on . The database is on my computer so everything should return right away . I am using the package NPGSQL version 3.2.5 and got my code running from following this example http://www.npgsql.org/doc/index.html .

public string getData()
        {
            string results = "";
            string connection = "connection to database";
                using (var conn = new NpgsqlConnection(connection))
            {
                 conn.Open();
                using (var cmd = new NpgsqlCommand("select json_build_object('Locations', array_to_json(array_agg(t))) from (SELECT latitudes,county,longitudes," +"statelong,thirtylatmin,thirtylatmax,thirtylonmin,thirtylonmax,city" +" FROM zips where city='Chicago' ORDER BY city limit 5) t", conn))
                     using (var reader =  cmd.ExecuteReader())
                        while (reader.Read())
                        results =  reader.GetString(0);


                }

            return results;
        }

I also did the test and made everything asynchronous which improved the first request time to 712 ms but the 100th request took even longer 17 seconds .

public async Task<string> B()
{
    string results = "";
    string connection = "my connection";
        using (var conn = new NpgsqlConnection(connection))
    {
        await conn.OpenAsync();
        using (var cmd = new NpgsqlCommand("select json_build_object('Locations', array_to_json(array_agg(t))) from (SELECT latitudes,county,longitudes," +"statelong,thirtylatmin,thirtylatmax,thirtylonmin,thirtylonmax,city" +" FROM zips where city='Chicago' ORDER BY city limit 5) t", conn))
        using (var reader = await cmd.ExecuteReaderAsync())
            while (await reader.ReadAsync())
                results =  reader.GetString(0);

        }

    return results;
}

The images of the test can be found here essentially the results are

.net core 2.0 Sync: 1st request = 2.5 seconds    : 100th request = 13 seconds

.net core 2.0 Async: 1st request = 717 milli-seconds    : 100th request = 17 seconds

Golang: 1st request = 47 milliseconds   : 100th request = 14 milliseconds

  I'm either missing something with optimization or maybe the library NPGSQL has some big issues . I do not know why there is such a big difference in request times between the Go version and the .net core version . I would like to use the .net core version in production however the performance issue would not allow it . Any suggestions for making this faster ? Again I am using .net core version 2.0 on Mac and the postgres database . I have not changed anything in .net core as far as settings go . Also I don't know if it is relevant but I am using localhost:5002

{"iisSettings": {"windowsAuthentication": false,"anonymousAuthentication": true,"iisExpress": {"applicationUrl": "http://localhost:55556/","sslPort": 0
    }
  },"profiles": {"IIS Express": {"commandName": "IISExpress","launchBrowser": true,"environmentVariables": {"ASPNETCORE_ENVIRONMENT": "Development"
      }
    },"Yisly": {"commandName": "Project","launchBrowser": true,"environmentVariables": {"ASPNETCORE_ENVIRONMENT": "Development"
      },"applicationUrl": "http://localhost:5002/"
    }
  }
}