Struct SubqueryExecutor 

pub struct SubqueryExecutor {
    pub runtime: Arc<ExecutionRuntime>,
    pub bindings: Arc<QueryBindings>,
    pub runners: HashMap<u64, SubqueryRunner>,
}

Per-operator subquery execution facility.

Each Filter/Project/Assign operator instance holds exactly one executor with its own runner instances; nothing is shared across partitions. Execution is always synchronous and serial within the operator’s own next() call stack, so the runners need no cross-thread locks.

Fields

runtime: Arc<ExecutionRuntime>

Shared runtime used to re-materialize nested sub-plans (storage, cancellation, parameters).

bindings: Arc<QueryBindings>

Bindings used to materialize nested sub-plans (parameter-free).

runners: HashMap<u64, SubqueryRunner>

Compiled runners keyed by stable SubqueryBody.id.

Implementations

impl SubqueryExecutor

pub fn from_specs( runtime: Arc<ExecutionRuntime>, bindings: Arc<QueryBindings>, specs: &[SubqueryRunnerSpec], ) -> Self

Build a per-operator executor from the immutable runner specs of an arena spec. Each call creates fresh runner state, so every operator instance (and every parallel partition) is isolated.

pub fn is_empty(&self) -> bool

Whether this executor hosts any compiled subqueries.

pub fn execute_exists( &self, body: &SubqueryBody, layout: Arc<SlotLayout>, row: Vec<Value>, ) -> Result<bool, ExpressionError>

EXISTS: whether the subquery produces at least one row.

Non-correlated: evaluated once on the first call and cached. Correlated: re-executed per row with the current row as the frame. Group-Join form: answered from the materialized key→aggregate table (the key is present iff at least one right row matched).

pub fn execute_contains( &self, body: &SubqueryBody, layout: Arc<SlotLayout>, row: Vec<Value>, value: &Value, ) -> Result<bool, ExpressionError>

IN: whether value occurs in the subquery result column.

NULL never matches, mirroring the conjunctive keys_match path. Non-correlated: the result set is collected once (NULLs removed) into a HashSet and probed per row. Group-Join form: the lookup value is compared against the aggregated result of the row’s key.

pub fn execute_scalar( &self, body: &SubqueryBody, layout: Arc<SlotLayout>, row: Vec<Value>, ) -> Result<Value, ExpressionError>

Scalar subquery: the first result value, or NULL when the subquery returns no rows.

Non-correlated: evaluated once on the first call and cached. Correlated: re-executed per row with the current row as the frame. Group-Join form: answered from the materialized key→aggregate table; a missing key yields NULL.

Trait Implementations

impl Debug for SubqueryExecutor

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

Formats the value using the given formatter.