Struct Section 

struct Section {
    bytes: Bytes,
    metadata: ArrowReaderMetadata,
}

One Parquet section of the cached blob, with its footer parsed ONCE. Re-opening a ParquetRecordBatchReaderBuilder per row group re-parses the whole footer each time, which is quadratic in the row-group count — hundreds of milliseconds on a model that streamed a few hundred batches.

Fields

bytes: Bytes

metadata: ArrowReaderMetadata

Implementations

impl Section

fn open(bytes: Bytes) -> Option<Self>

fn read_all(&self) -> Option<RecordBatch>

The whole table as one RecordBatch, however many row groups it has (none included).

fn row_groups(&self) -> usize

fn read_row_group(&self, index: usize) -> Option<RecordBatch>

Read row group index as one RecordBatch. The reader’s batch size is pinned to the group’s own row count so it yields a single batch instead of fragments that would then have to be copied back together.