Module index 

Property index support for efficient lookups.

This module provides property indexes that transform O(n) property scans into O(log n) or O(1) lookups, dramatically improving query performance on large graphs.

Index Types

Type	Use Case	Lookup Complexity
BTreeIndex	Range queries, ordered iteration	O(log n) + O(k)
UniqueIndex	Exact match with uniqueness constraint	O(1) average

Example

use interstellar::index::IndexBuilder;
use interstellar::storage::Graph;

let graph = Graph::new();

// Create a B+ tree index for range queries
graph.create_index(
    IndexBuilder::vertex()
        .label("person")
        .property("age")
        .build()
        .unwrap()
).unwrap();

// Create a unique index for O(1) lookups with uniqueness constraint
graph.create_index(
    IndexBuilder::vertex()
        .label("user")
        .property("email")
        .unique()
        .build()
        .unwrap()
).unwrap();

// Queries automatically use indexes when applicable
let adults = graph.gremlin().v()
    .has_label("person")
    .has_where("age", p::gte(18))
    .to_list();

How It Works

1. Index Creation: When you create an index, existing data is scanned and indexed. The index is then maintained automatically on insert/update/delete.

2. Automatic Selection: Filter steps like has_value() and has_where() check for applicable indexes and use them when beneficial.

3. Transparent Integration: Both the Gremlin-style traversal API and GQL queries benefit from indexes without any API changes.

Structs

BTreeIndex

B+ tree index for range queries.

IndexBuilder

Fluent builder for index creation.

IndexFilter

A filter that can potentially use an index.

IndexSpec

Specification for creating an index.

IndexStatistics

Statistics for query optimization.

UniqueIndex

Hash-based unique index with O(1) lookup.

Enums

ElementType

Element type for indexing.

IndexError

Errors that can occur during index operations.

IndexPredicate

Predicates that can use indexes.

IndexType

Type of index structure.

Traits

PropertyIndex

Trait for property index implementations.