Struct datafusion::datasource::empty::EmptyTable

pub struct EmptyTable { /* private fields */ }

A table with a schema but no data.

Implementations

impl EmptyTable

pub fn new(schema: SchemaRef) -> Self

Initialize a new EmptyTable from a schema.

pub fn with_partitions(self, partitions: usize) -> Self

Creates a new EmptyTable with specified partition number.

Trait Implementations

impl TableProvider for EmptyTable

fn as_any(&self) -> &dyn Any

Returns the table provider as Any so that it can be downcast to a specific implementation.

fn schema(&self) -> SchemaRef

Get a reference to the schema for this table

fn table_type(&self) -> TableType

Get the type of this table for metadata/catalog purposes.

fn scan<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, _state: &'life1 SessionState, projection: Option<&'life2 Vec<usize>>, _filters: &'life3 [Expr], _limit: Option<usize> ) -> Pin<Box<dyn Future<Output = Result<Arc<dyn ExecutionPlan>>> + Send + 'async_trait>>where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait,

Create an ExecutionPlan that will scan the table. The table provider will be usually responsible of grouping the source data into partitions that can be efficiently parallelized or distributed.

fn get_table_definition(&self) -> Option<&str>

Get the create statement used to create this table, if available.

fn get_logical_plan(&self) -> Option<&LogicalPlan>

Get the Logical Plan of this table, if available.

fn supports_filter_pushdown( &self, _filter: &Expr ) -> Result<TableProviderFilterPushDown>

Tests whether the table provider can make use of a filter expression to optimise data retrieval.

fn statistics(&self) -> Option<Statistics>

Get statistics for this table, if available