Struct ApplyOperator 

pub struct ApplyOperator { /* private fields */ }

Apply (lateral join) operator.

Evaluates inner once for each row of outer. The result schema is outer_columns ++ inner_columns. If the inner plan produces zero rows for a given outer row, that outer row is omitted (inner join semantics).

When param_state is set, outer row values for the specified column indices are injected into the shared ParameterState before each inner execution, allowing the inner plan’s ParameterScanOperator to read them.

Implementations

impl ApplyOperator

pub fn new(outer: Box<dyn Operator>, inner: Box<dyn Operator>) -> Self

Creates a new Apply operator (uncorrelated: no parameter injection).

pub fn new_correlated( outer: Box<dyn Operator>, inner: Box<dyn Operator>, param_state: Arc<ParameterState>, param_col_indices: Vec<usize>, ) -> Self

Creates a correlated Apply operator that injects outer row values.

param_state is shared with a ParameterScanOperator in the inner plan. param_col_indices specifies which outer columns to inject (by index).

pub fn with_optional(self, inner_column_count: usize) -> Self

Enables optional (left-join) semantics with the given inner column count.

When enabled, outer rows that produce no inner results will be emitted with NULL values for the inner columns instead of being dropped.

pub fn with_exists_mode(self, keep_matches: bool) -> Self

Enables EXISTS mode: semi-join (keep_matches=true) or anti-join (keep_matches=false). Inner columns are NOT appended to the output.

Trait Implementations

impl Operator for ApplyOperator

fn next(&mut self) -> OperatorResult

Pulls the next batch of data. Returns None when exhausted.

fn reset(&mut self)

Resets to initial state so you can iterate again.

fn name(&self) -> &'static str

Returns a name for debugging/explain output.