/// <summary> /// Test read, to be defined /// </summary> public DataSet Read() { _meta = ReadMetadata(); var ds = new DataSet(new Schema(_meta)); var cols = new List <IList>(); foreach (Thrift.RowGroup rg in _meta.Row_groups) { foreach (Thrift.ColumnChunk cc in rg.Columns) { var p = new PColumn(cc, ds.Schema, _input, _thrift, _options); string columnName = string.Join(".", cc.Meta_data.Path_in_schema); try { IList column = p.Read(columnName); cols.Add(column); } catch (Exception ex) { throw new ParquetException($"fatal error reading column '{columnName}'", ex); } } } ds.AddColumnar(cols); return(ds); }