Type Alias DfSendableRecordBatchStream

pub type DfSendableRecordBatchStream = Pin<Box<dyn RecordBatchStream<Item = Result<RecordBatch, DataFusionError>> + Send>>;

Trait for a [Stream] of RecordBatches that can be passed between threads

This trait is used to retrieve the results of DataFusion execution plan nodes.

The trait is a specialized Rust Async [Stream] that also knows the schema of the data it will return (even if the stream has no data). Every RecordBatch returned by the stream should have the same schema as returned by schema.

Error Handling

Once a stream returns an error, it should not be polled again (the caller should stop calling next) and handle the error.

However, returning Ready(None) (end of stream) is likely the safest behavior after an error. Like [Stream]s, RecordBatchStreams should not be polled after end of stream or returning an error. However, also like [Stream]s there is no mechanism to prevent callers polling so returning Ready(None) is recommended.

Aliased Type

struct DfSendableRecordBatchStream {}