// ColumnScanner returns a single scanner across all the Row Groups
func (fd *FileDescriptor) ColumnScanner(colname string) (*column.Scanner, error) {
elementSchema := fd.Schema().ColumnByName(colname).SchemaElement
chunks, err := fd.meta.GetColumnChunks(colname)
if err != nil {
return nil, fmt.Errorf("could not get columnChunks: %s", err)
}
return column.NewScanner(fd, elementSchema, chunks), nil
}
func (rg *RowGroupScanner) NewColumnScanners() []*column.Scanner {
var columnScanners []*column.Scanner
for idx, columnSchema := range rg.columns {
chunk := rg.rowGroup.GetColumns()[idx]
columnScanners = append(columnScanners, column.NewScanner(rg.r, columnSchema, []*thrift.ColumnChunk{chunk}))
}
return columnScanners
}