Trait datafusion::exec::SimpleRelation

pub trait SimpleRelation {
    fn scan<'a>(
        &'a mut self
    ) -> Box<Iterator<Item = Result<Rc<RecordBatch>>> + 'a>;
    fn schema<'a>(&'a self) -> &'a Schema;
}

trait for all relations (a relation is essentially just an iterator over rows with a known schema)

Required Methods

Important traits for Box<R>

impl<R> Read for Box<R> where
    R: Read + ?Sized, impl<W> Write for Box<W> where
    W: Write + ?Sized, impl<I> Iterator for Box<I> where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

fn scan<'a>(&'a mut self) -> Box<Iterator<Item = Result<Rc<RecordBatch>>> + 'a>

scan all records in this relation

fn schema<'a>(&'a self) -> &'a Schema

get the schema for this relation

Implementors

• impl SimpleRelation for AggregateRelation

• impl SimpleRelation for FilterRelation

• impl SimpleRelation for LimitRelation

• impl SimpleRelation for ProjectRelation