Crate lance_graph 

Lance Graph Query Engine

This crate provides graph query capabilities for Lance datasets using Cypher syntax. It interprets Lance datasets as property graphs and translates Cypher queries into DataFusion SQL queries for execution.

Features

• Cypher query parsing and AST representation
• Graph pattern matching on columnar data
• Property graph interpretation of Lance datasets
• Translation to optimized SQL via DataFusion
• Support for nodes, relationships, and properties

Example

use lance_graph::{CypherQuery, GraphConfig, Result};

let config = GraphConfig::builder()
    .with_node_label("Person", "person_id")
    .with_relationship("KNOWS", "src_person_id", "dst_person_id")
    .build()?;

let query = CypherQuery::new("MATCH (p:Person) WHERE p.age > 30 RETURN p.name")?
    .with_config(config);

// Execute against a dataset (would need actual dataset integration)
// let results = query.execute(&dataset).await?;

Re-exports

pub use config::GraphConfig;

pub use config::NodeMapping;

pub use config::RelationshipMapping;

pub use error::GraphError;

pub use error::Result;

pub use lance_vector_search::VectorSearch;

pub use query::CypherQuery;

pub use query::ExecutionStrategy;

pub use sql_query::SqlQuery;

pub use table_readers::DeltaTableReader;

pub use table_readers::default_table_readers;

pub use table_readers::ParquetTableReader;

Modules

ast

Abstract Syntax Tree for Cypher queries

case_insensitive

Case-insensitive string utilities

config

Graph configuration for mapping Lance datasets to property graphs

datafusion_planner

DataFusion-based physical planner for graph queries

error

Error types for the Lance graph query engine

lance_native_planner

Lance Native physical planner (placeholder)

lance_vector_search

Lance Vector Search API for lance-graph

logical_plan

Logical planning for graph queries

parameter_substitution

parser

Cypher query parser

query

High-level Cypher query interface for Lance datasets

semantic

Semantic analysis for graph queries

sql_catalog

Bridge between catalog connectors and the SQL query engine.

sql_query

Direct SQL query interface for Lance datasets

table_readers

Built-in TableReader implementations for common data formats.

Structs

CatalogInfo

Metadata about a catalog (top-level namespace).

ColumnInfo

Metadata about a column in a table.

Connector

Bundles a CatalogProvider with TableReaders for convenient use.

DirNamespace

A namespace that resolves table names relative to a base directory or URI.

InMemoryCatalog

A simple in-memory catalog useful for tests and bootstrap wiring.

SchemaInfo

Metadata about a schema (second-level namespace within a catalog).

SimpleTableSource

A trivial logical table source with a fixed schema.

TableInfo

Full table metadata including columns and storage information.

UnityCatalogConfig

Configuration for connecting to a Unity Catalog server.

UnityCatalogProvider

Unity Catalog REST API client.

Enums

CatalogError

Errors that can occur during catalog operations.

DataSourceFormat

Data format of the underlying storage.

TableType

Type of table (managed vs external).

Constants

MAX_VARIABLE_LENGTH_HOPS

Maximum allowed hops for variable-length relationship expansion (e.g., *1..N)

Traits

CatalogProvider

Abstract trait for browsing an external catalog.

GraphSourceCatalog

A minimal catalog to resolve node labels and relationship types to logical table sources.

TableReader

Reads table data in a specific format and registers it into a DataFusion SessionContext.

Type Aliases

CatalogResult