pub fn get_column_iterator<R>(
reader: R,
row_group: &RowGroupMetaData,
field_name: &str,
page_filter: Option<Arc<dyn Fn(&Descriptor, &DataPageHeader) -> bool + Sync + Send>>,
scratch: Vec<u8>,
max_page_size: usize
) -> ColumnIterator<R>Expand description
Returns a ColumnIterator of column chunks corresponding to field.
Contrarily to get_page_iterator that returns a single iterator of pages, this iterator
iterates over columns, one by one, and returns a PageReader per column.
For primitive fields (e.g. i64), ColumnIterator yields exactly one column.
For complex fields, it yields multiple columns.
max_page_size is the maximum number of bytes allowed.