Struct OptionalMatchNode 

pub struct OptionalMatchNode {
    pub outer: Arc<LogicalPlan>,
    pub optional: Arc<LogicalPlan>,
    pub join_keys: Vec<(usize, usize)>,
    pub inner_keep_idx: Vec<usize>,
    /* private fields */
}

Physical node for OPTIONAL MATCH (LEFT OUTER semantics with openCypher null-shaping over a sub-plan).

The physical layer (OptionalMatchExec in M13) left-joins the outer (mandatory) input against the optional sub-plan on the shared pattern variables (join_keys), preserving every outer row and setting the optional-side columns to null when there is no match — distinct from a SQL LEFT JOIN only in that the shared join-key columns are not duplicated on the output (they belong to the outer side).

Output schema

outer fields, followed by the optional fields that are not join keys, each made nullable (an unmatched outer row nulls them all).

Fields

outer: Arc<LogicalPlan>

The outer (mandatory) input.

optional: Arc<LogicalPlan>

The optional sub-plan.

join_keys: Vec<(usize, usize)>

Shared-variable join keys as (outer_col_idx, inner_col_idx) pairs, resolved against the qualified input schemas at lowering time.

inner_keep_idx: Vec<usize>

Inner (optional-side) column indices to append to the output, in order. Excludes every shared-variable column — not merely the join-key columns — because a shared variable’s whole node (e.g. a in MATCH (a) OPTIONAL MATCH (a)-[:R]->(b)) is carried by the outer side; appending its columns again would duplicate the var_<shared> fields.

Implementations

impl OptionalMatchNode

pub fn new( outer: Arc<LogicalPlan>, optional: Arc<LogicalPlan>, join_keys: Vec<(usize, usize)>, inner_keep_idx: Vec<usize>, ) -> Self

Create an optional-match node.

inner_keep_idx lists the optional plan’s column indices to append to the output (every column of a shared variable already excluded — those live on the outer side). Passed by the lowerer, which resolves them against the qualified inner schema, so this crate needs no graphforge-rel/graphforge-storage dependency. The node appends the corresponding fields to the outer schema as nullable columns (an unmatched outer row nulls them all).

Trait Implementations

impl Clone for OptionalMatchNode

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for OptionalMatchNode

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

Formats the value using the given formatter.

impl Eq for OptionalMatchNode

impl Hash for OptionalMatchNode

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for OptionalMatchNode

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for OptionalMatchNode

fn partial_cmp(&self, _other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for OptionalMatchNode

impl UserDefinedLogicalNodeCore for OptionalMatchNode

fn name(&self) -> &str

Return the plan’s name.

fn inputs(&self) -> Vec<&LogicalPlan>

Return the logical plan’s inputs.

fn schema(&self) -> &DFSchemaRef

Return the output schema of this logical plan node.

fn expressions(&self) -> Vec<Expr>

Returns all expressions in the current logical plan node. This should not include expressions of any inputs (aka non-recursively). These expressions are used for optimizer passes and rewrites.

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

Write a single line, human readable string to f for use in explain plan.

fn with_exprs_and_inputs( &self, _exprs: Vec<Expr>, inputs: Vec<LogicalPlan>, ) -> DfResult<Self>

Create a new UserDefinedLogicalNode with the specified children and expressions. This function is used during optimization when the plan is being rewritten and a new instance of the UserDefinedLogicalNode must be created.

fn check_invariants( &self, _check: InvariantLevel, ) -> Result<(), DataFusionError>

Perform check of invariants for the extension node.

fn prevent_predicate_push_down_columns(&self) -> HashSet<String>

A list of output columns (e.g. the names of columns in self.schema()) for which predicates can not be pushed below this node without changing the output.

fn necessary_children_exprs( &self, _output_columns: &[usize], ) -> Option<Vec<Vec<usize>>>

Returns the necessary input columns for this node required to compute the columns in the output schema

fn supports_limit_pushdown(&self) -> bool

Returns true if a limit can be safely pushed down through this UserDefinedLogicalNode node.