OutOfMemoryException returning large set of data f

问题:

We created a Web API which queries the Oracle Database and returns the result in JSON format. If the data returned is very large it throws an Out of Exception issue. So it was suggested in the other question the issue is because loading that entire result set into memory before serializing it out to the HttpResponseMessage.

So created the below classes

[JsonConverter(typeof(OracleDataTableJsonResponseConverter))]
public sealed class OracleDataTableJsonResponse
{
public string ConnectionString { get; private set; }
public string QueryString { get; private set; }
public OracleParameter[] Parameters { get; private set; }

public OracleDataTableJsonResponse(string connStr, string strQuery, OracleParameter[] prms)
{
    this.ConnectionString = connStr;
    this.QueryString = strQuery;
    this.Parameters = prms;
}
}

class OracleDataTableJsonResponseConverter : JsonConverter
 {
public override bool CanConvert(Type objectType)
{
    return objectType == typeof(OracleDataTableJsonResponse);
}

public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
    throw new NotImplementedException("OracleDataTableJsonResponse is only for writing JSON.  To read, deserialize into a DataTable");
}

public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
    var response = (OracleDataTableJsonResponse)value;

    using (var dbconn = new OracleConnection(response.ConnectionString))
    {
        using (var selectCommand = new OracleCommand(response.QueryString, dbconn))
        {
            if (response.Parameters != null)
                selectCommand.Parameters.AddRange(response.Parameters);
            using (var reader = selectCommand.ExecuteReader())
            {
                writer.WriteDataTable(reader, serializer);
            }
        }
    }
}
}

public static class JsonExtensions
{
public static void WriteDataTable(this JsonWriter writer, IDataReader reader, JsonSerializer serializer)
{
    if (writer == null || reader == null || serializer == null)
        throw new ArgumentNullException();
    writer.WriteStartArray();
    while (reader.Read())
    {
        writer.WriteStartObject();
        for (int i = 0; i < reader.FieldCount; i++)
        {
            writer.WritePropertyName(reader.GetName(i));
            serializer.Serialize(writer, reader[i]);
        }
        writer.WriteEndObject();
    }
    writer.WriteEndArray();
}
}

And the API Controller as

public HttpResponseMessage Getdetails([FromUri] string[] id)
{
    var prms = new List<OracleParameter>();
    var connStr = ConfigurationManager.ConnectionStrings["PDataConnection"].ConnectionString;
    var inconditions = id.Distinct().ToArray();
    var strQuery = @"SELECT 
                   STCD_PRIO_CATEGORY_DESCR.DESCR AS CATEGORY, 
                   STCD_PRIO_CATEGORY_DESCR.SESSION_NUM AS SESSION_NUMBER, 
                   Trunc(STCD_PRIO_CATEGORY_DESCR.START_DATE) AS SESSION_START_DATE, 
                   STCD_PRIO_CATEGORY_DESCR.START_DATE AS SESSION_START_TIME , 
                   Trunc(STCD_PRIO_CATEGORY_DESCR.END_DATE) AS SESSION_END_DATE, 
                     FROM 
                     STCD_PRIO_CATEGORY_DESCR, 
                     WHERE 
                    STCD_PRIO_CATEGORY_DESCR.STD_REF IN(";
    var sb = new StringBuilder(strQuery);
    for (int x = 0; x < inconditions.Length; x++)
    {
        sb.Append(":p" + x + ",");
        var p = new OracleParameter(":p" + x, OracleDbType.NVarchar2);
        p.Value = inconditions[x];
        prms.Add(p);
    }
    if (sb.Length > 0)// Should this be inconditions.Length > 0  ?
        sb.Length--;
    strQuery = sb.Append(")").ToString();

    var returnObject = new { data = new OracleDataTableJsonResponse(connStr, strQuery, prms.ToArray()) };
    var response = Request.CreateResponse(HttpStatusCode.OK, returnObject, MediaTypeHeaderValue.Parse("application/json"));
    ContentDispositionHeaderValue contentDisposition = null;
    if (ContentDispositionHeaderValue.TryParse("inline; filename=ProvantisStudyData.json", out contentDisposition))
    {
        response.Content.Headers.ContentDisposition = contentDisposition;
    }
    return response;
 }

The Out of Memory exception still exists

Wat could be the issue any help is greatly appreciated. I am new to the ASP.NET and Oracle connections and kind of stuck here. Any help is greatly appreciated