Struct Project 

pub struct Project<'a> { /* private fields */ }

Per-row scalar projection. Each (alias, expr) pair is evaluated against the input row and written under alias in the output. The child schema is replaced with the output aliases.

Implementations

impl Project<'static>

pub fn new( child: Box<dyn PhysicalOperator>, projections: Vec<(String, ScalarExpr)>, params: Vec<SQLParam>, ) -> Self

pub fn appending( child: Box<dyn PhysicalOperator>, projections: Vec<(String, ScalarExpr)>, params: Vec<SQLParam>, ) -> Self

Variant that keeps every input column in the output and appends the projections at the end. Used by aggregate / window paths.

impl<'a> Project<'a>

pub fn with_evaluator( child: Box<dyn PhysicalOperator + 'a>, projections: Vec<(String, ScalarExpr)>, evaluator: SharedExpressionEvaluator<'a>, ) -> Self

pub fn appending_with_evaluator( child: Box<dyn PhysicalOperator + 'a>, projections: Vec<(String, ScalarExpr)>, evaluator: SharedExpressionEvaluator<'a>, ) -> Self

Trait Implementations

impl PhysicalOperator for Project<'_>

fn row_schema(&self) -> &RowSchema

Complete logical-to-physical row layout emitted by this operator. Every Batch returned by Self::next must carry this exact schema; operators must reject a child that violates that invariant.

fn output_ordering(&self) -> &[PhysicalOrder]

Leading output ordering known to be preserved by this operator.

fn open(&mut self) -> ExecResult<()>

fn next(&mut self) -> ExecResult<Option<Batch>>

fn close(&mut self) -> ExecResult<()>

fn schema(&self) -> &[String]

Schema column names in logical output order.

fn estimated_cardinality(&self) -> Option<u64>

Planner/runtime cardinality estimate for choosing physical strategies. None means the operator cannot provide a useful estimate. The value is advisory rather than a correctness bound.

fn consume_into_aggregate( &mut self, _executor: &mut dyn AggregateExecutor, ) -> ExecResult<bool>

Let a leaf consume its native projected rows directly into an aggregate executor. Returning false promises that no input was consumed, so the caller can fall back to ordinary Batch pulls.