Trait datafusion::exec::SimpleRelation
[−]
[src]
pub trait SimpleRelation { fn scan<'a>(
&'a self,
ctx: &'a ExecutionContext
) -> Box<Iterator<Item = Result<Row, ExecutionError>> + 'a>; fn schema<'a>(&'a self) -> &'a Schema; }
trait for all relations (a relation is essentially just an iterator over tuples with a known schema)
Required Methods
fn scan<'a>(
&'a self,
ctx: &'a ExecutionContext
) -> Box<Iterator<Item = Result<Row, ExecutionError>> + 'a>
&'a self,
ctx: &'a ExecutionContext
) -> Box<Iterator<Item = Result<Row, ExecutionError>> + 'a>
scan all records in this relation
fn schema<'a>(&'a self) -> &'a Schema
get the schema for this relation
Implementors
impl SimpleRelation for CsvRelation
impl SimpleRelation for FilterRelation
impl SimpleRelation for SortRelation
impl SimpleRelation for ProjectRelation
impl SimpleRelation for LimitRelation