Struct datafusion_physical_expr::expressions::RowNumber

pub struct RowNumber { /* private fields */ }

row_number expression

Implementations

impl RowNumber

pub fn new(name: impl Into<String>) -> Self

Create a new ROW_NUMBER function

Trait Implementations

impl BuiltInWindowFunctionExpr for RowNumber

fn as_any(&self) -> &dyn Any

Return a reference to Any that can be used for downcasting

fn field(&self) -> Result<Field>

The field of the final result of evaluating this window function.

fn expressions(&self) -> Vec<Arc<dyn PhysicalExpr>>

Expressions that are passed to the PartitionEvaluator.

fn name(&self) -> &str

Human readable name such as "MIN(c2)" or "RANK()". The default implementation returns placeholder text.

fn get_result_ordering(&self, schema: &SchemaRef) -> Option<PhysicalSortExpr>

Returns the ordering introduced by the window function, if applicable. Most window functions don’t introduce an ordering, hence the default value is None. Note that this information is used to update ordering equivalences.

fn create_evaluator(&self) -> Result<Box<dyn PartitionEvaluator>>

Create a PartitionEvaluator for evaluating the function on a particular partition.

fn evaluate_args(&self, batch: &RecordBatch) -> Result<Vec<ArrayRef>>

Evaluate window function’s arguments against the input window batch and return an ArrayRef.

fn reverse_expr(&self) -> Option<Arc<dyn BuiltInWindowFunctionExpr>>

Construct a new BuiltInWindowFunctionExpr that produces the same result as this function on a window with reverse order. The return value of this function is used by the DataFusion optimizer to avoid re-sorting the data when possible.

impl Debug for RowNumber

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

Formats the value using the given formatter.