private static void RunSearch()
    {
        var hostWeb = "my site";
        using (ClientContext ctx = new ClientContext(new Uri(hostWeb)))
        {
            DataTable resultDataTable = new DataTable();
            DataColumn titleCol = new DataColumn("Title");
            DataColumn pathCol = new DataColumn("Path");
            resultDataTable.Columns.Add(titleCol);
            resultDataTable.Columns.Add(pathCol);

            int currentRowIindex = 0;
            var resultTable = GetSearchResults(0, ctx, "allow");

            if (null != resultTable && resultTable.TotalRowsIncludingDuplicates > 0)
            {
                while(resultTable.TotalRowsIncludingDuplicates > resultDataTable.Rows.Count)
                {
                    foreach(var resultRow in resultTable.ResultRows)
                    {
                        DataRow row = resultDataTable.NewRow();
                        row["Title"] = resultRow["Title"];
                        row["Path"] = resultRow["Path"];
                        resultDataTable.Rows.Add(row);
                    }
                    currentRowIindex = resultDataTable.Rows.Count;
                    resultTable = null;
                    resultTable = GetSearchResults(currentRowIindex, ctx, "allow");
                    if(null != resultTable&&resultTable.TotalRowsIncludingDuplicates > 0)
                    {
                        if (resultTable.RowCount <= 0)
                        {
                            break;

                        }
                        else
                            break;
                    }

                }
                Console.WriteLine("Total Results: {0}", resultDataTable.Rows.Count);
                Console.ReadLine();
            }
        }
    }

private static ResultTable GetSearchResults(int startIndex, ClientContext clientContext, string searchValue)
    {
        ClientResult<ResultTableCollection> results = null;
        try
        {
            KeywordQuery keywordQuery = new KeywordQuery(clientContext);
            SearchExecutor searchExecutor = new SearchExecutor(clientContext);
            keywordQuery.StartRow = startIndex;
            keywordQuery.QueryText = searchValue;
            keywordQuery.RowLimit = 500;
            keywordQuery.RowsPerPage = 500;
            keywordQuery.TrimDuplicates = true;
            keywordQuery.SortList.Add("Rank", SortDirection.Descending);
            keywordQuery.Timeout = 10000; //10 minutes
            results = searchExecutor.ExecuteQuery(keywordQuery);
            clientContext.ExecuteQuery();
            return results.Value.FirstOrDefault(v => v.TableType.Equals(KnownTableTypes.RelevantResults));
        }
        catch (Exception)
        {
            throw;
        }
    }