Struct EmptyTable

pub struct EmptyTable { /* private fields */ }

An empty plan that is useful for testing and generating plans without mapping them to actual 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 Debug for EmptyTable

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

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 dyn Session, 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 for scanning the table with optionally specified projection, filter and limit, described below.

fn constraints(&self) -> Option<&Constraints>

Get a reference to the constraints of the table. Returns:

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

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

fn get_logical_plan(&self) -> Option<Cow<'_, LogicalPlan>>

Get the LogicalPlan of this table, if available.

fn get_column_default(&self, _column: &str) -> Option<&Expr>

Get the default value for a column, if available.

fn supports_filters_pushdown( &self, filters: &[&Expr], ) -> Result<Vec<TableProviderFilterPushDown>, DataFusionError>

Specify if DataFusion should provide filter expressions to the TableProvider to apply during the scan.

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

Get statistics for this table, if available Although not presently used in mainline DataFusion, this allows implementation specific behavior for downstream repositories, in conjunction with specialized optimizer rules to perform operations such as re-ordering of joins.

fn insert_into<'life0, 'life1, 'async_trait>( &'life0 self, _state: &'life1 dyn Session, _input: Arc<dyn ExecutionPlan>, _insert_op: InsertOp, ) -> Pin<Box<dyn Future<Output = Result<Arc<dyn ExecutionPlan>, DataFusionError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Return an ExecutionPlan to insert data into this table, if supported.