Struct NullGraphStore 

pub struct NullGraphStore;

A no-op GraphStore that returns empty results for all queries.

Used by the RDF planner to satisfy the expression evaluator’s store requirement. SPARQL expression functions (STR, LANG, DATATYPE, etc.) operate on already-materialized values in DataChunk columns and never call store methods.

Trait Implementations

impl GraphStore for NullGraphStore

fn get_node(&self, _: NodeId) -> Option<Node>

Returns a node by ID (latest visible version at current epoch).

fn get_edge(&self, _: EdgeId) -> Option<Edge>

Returns an edge by ID (latest visible version at current epoch).

fn get_node_versioned( &self, _: NodeId, _: EpochId, _: TransactionId, ) -> Option<Node>

Returns a node visible to a specific transaction.

fn get_edge_versioned( &self, _: EdgeId, _: EpochId, _: TransactionId, ) -> Option<Edge>

Returns an edge visible to a specific transaction.

fn get_node_at_epoch(&self, _: NodeId, _: EpochId) -> Option<Node>

Returns a node using pure epoch-based visibility (no transaction context).

fn get_edge_at_epoch(&self, _: EdgeId, _: EpochId) -> Option<Edge>

Returns an edge using pure epoch-based visibility (no transaction context).

fn get_node_property(&self, _: NodeId, _: &PropertyKey) -> Option<Value>

Gets a single property from a node without loading all properties.

fn get_edge_property(&self, _: EdgeId, _: &PropertyKey) -> Option<Value>

Gets a single property from an edge without loading all properties.

fn get_node_property_batch( &self, ids: &[NodeId], _: &PropertyKey, ) -> Vec<Option<Value>>

Gets a property for multiple nodes in a single batch operation.

fn get_nodes_properties_batch( &self, ids: &[NodeId], ) -> Vec<FxHashMap<PropertyKey, Value>>

Gets all properties for multiple nodes in a single batch operation.

fn get_nodes_properties_selective_batch( &self, ids: &[NodeId], _: &[PropertyKey], ) -> Vec<FxHashMap<PropertyKey, Value>>

Gets selected properties for multiple nodes (projection pushdown).

fn get_edges_properties_selective_batch( &self, ids: &[EdgeId], _: &[PropertyKey], ) -> Vec<FxHashMap<PropertyKey, Value>>

Gets selected properties for multiple edges (projection pushdown).

fn neighbors(&self, _: NodeId, _: Direction) -> Vec<NodeId>

Returns neighbor node IDs in the specified direction.

fn edges_from(&self, _: NodeId, _: Direction) -> Vec<(NodeId, EdgeId)>

Returns (target_node, edge_id) pairs for edges from a node.

fn out_degree(&self, _: NodeId) -> usize

Returns the out-degree of a node (number of outgoing edges).

fn in_degree(&self, _: NodeId) -> usize

Returns the in-degree of a node (number of incoming edges).

fn has_backward_adjacency(&self) -> bool

Whether backward adjacency is available for incoming edge queries.

fn node_ids(&self) -> Vec<NodeId>

Returns all non-deleted node IDs, sorted by ID.

fn nodes_by_label(&self, _: &str) -> Vec<NodeId>

Returns node IDs with a specific label.

fn node_count(&self) -> usize

Returns the total number of non-deleted nodes.

fn edge_count(&self) -> usize

Returns the total number of non-deleted edges.

fn edge_type(&self, _: EdgeId) -> Option<ArcStr>

Returns the type string of an edge.

fn find_nodes_by_property(&self, _: &str, _: &Value) -> Vec<NodeId>

Finds all nodes with a specific property value. Uses indexes when available.

fn find_nodes_by_properties(&self, _: &[(&str, Value)]) -> Vec<NodeId>

Finds nodes matching multiple property equality conditions.

fn find_nodes_in_range( &self, _: &str, _: Option<&Value>, _: Option<&Value>, _: bool, _: bool, ) -> Vec<NodeId>

Finds nodes whose property value falls within a range.

fn node_property_might_match( &self, _: &PropertyKey, _: CompareOp, _: &Value, ) -> bool

Returns true if a node property predicate might match any nodes. Uses zone maps for early filtering.

fn edge_property_might_match( &self, _: &PropertyKey, _: CompareOp, _: &Value, ) -> bool

Returns true if an edge property predicate might match any edges.

fn statistics(&self) -> Arc<Statistics>

Returns the current statistics snapshot (cheap Arc clone).

fn estimate_label_cardinality(&self, _: &str) -> f64

Estimates cardinality for a label scan.

fn estimate_avg_degree(&self, _: &str, _: bool) -> f64

Estimates average degree for an edge type.

fn current_epoch(&self) -> EpochId

Returns the current MVCC epoch.

fn all_node_ids(&self) -> Vec<NodeId>

Returns all node IDs including uncommitted/PENDING versions.

fn edge_type_versioned( &self, id: EdgeId, epoch: EpochId, transaction_id: TransactionId, ) -> Option<ArcStr>

Returns the type string of an edge visible to a specific transaction.

fn has_property_index(&self, _property: &str) -> bool

Returns true if a property index exists for the given property.

fn all_labels(&self) -> Vec<String>

Returns all label names in the database.

fn all_edge_types(&self) -> Vec<String>

Returns all edge type names in the database.

fn all_property_keys(&self) -> Vec<String>

Returns all property key names used in the database.

fn is_node_visible_at_epoch(&self, id: NodeId, epoch: EpochId) -> bool

Checks if a node is visible at the given epoch without building the full Node.

fn is_node_visible_versioned( &self, id: NodeId, epoch: EpochId, transaction_id: TransactionId, ) -> bool

Checks if a node is visible to a specific transaction without building the full Node.

fn is_edge_visible_at_epoch(&self, id: EdgeId, epoch: EpochId) -> bool

Checks if an edge is visible at the given epoch without building the full Edge.

fn is_edge_visible_versioned( &self, id: EdgeId, epoch: EpochId, transaction_id: TransactionId, ) -> bool

Checks if an edge is visible to a specific transaction without building the full Edge.

fn filter_visible_node_ids(&self, ids: &[NodeId], epoch: EpochId) -> Vec<NodeId>

Filters node IDs to only those visible at the given epoch (batch).

fn filter_visible_node_ids_versioned( &self, ids: &[NodeId], epoch: EpochId, transaction_id: TransactionId, ) -> Vec<NodeId>

Filters node IDs to only those visible to a transaction (batch).

fn get_node_history(&self, _id: NodeId) -> Vec<(EpochId, Option<EpochId>, Node)>

Returns all versions of a node with their creation/deletion epochs, newest first.

fn get_edge_history(&self, _id: EdgeId) -> Vec<(EpochId, Option<EpochId>, Edge)>

Returns all versions of an edge with their creation/deletion epochs, newest first.