graphiti/graphiti_core/search/search_utils.py

"""
Copyright 2024, Zep Software, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""

import logging
from collections import defaultdict
from time import time
from typing import Any

import numpy as np
from numpy._typing import NDArray
from typing_extensions import LiteralString

from graphiti_core.driver.driver import GraphDriver
from graphiti_core.edges import EntityEdge, get_entity_edge_from_record
from graphiti_core.graph_queries import (
    get_nodes_query,
    get_relationships_query,
    get_vector_cosine_func_query,
)
from graphiti_core.helpers import (
    RUNTIME_QUERY,
    lucene_sanitize,
    normalize_l2,
    semaphore_gather,
)
from graphiti_core.nodes import (
    ENTITY_NODE_RETURN,
    CommunityNode,
    EntityNode,
    EpisodicNode,
    get_community_node_from_record,
    get_entity_node_from_record,
    get_episodic_node_from_record,
)
from graphiti_core.search.search_filters import (
    SearchFilters,
    edge_search_filter_query_constructor,
    node_search_filter_query_constructor,
)

logger = logging.getLogger(__name__)

RELEVANT_SCHEMA_LIMIT = 10
DEFAULT_MIN_SCORE = 0.6
DEFAULT_MMR_LAMBDA = 0.5
MAX_SEARCH_DEPTH = 3
MAX_QUERY_LENGTH = 32


def fulltext_query(query: str, group_ids: list[str] | None = None, fulltext_syntax: str = ''):
    group_ids_filter_list = (
        [fulltext_syntax + f"group_id:'{lucene_sanitize(g)}'" for g in group_ids] if group_ids is not None else []
    )
    group_ids_filter = ''
    for f in group_ids_filter_list:
        group_ids_filter += f if not group_ids_filter else f' OR {f}'

    group_ids_filter += ' AND ' if group_ids_filter else ''

    lucene_query = lucene_sanitize(query)
    # If the lucene query is too long return no query
    if len(lucene_query.split(' ')) + len(group_ids or '') >= MAX_QUERY_LENGTH:
        return ''

    full_query = group_ids_filter + '(' + lucene_query + ')'

    return full_query


async def get_episodes_by_mentions(
    driver: GraphDriver,
    nodes: list[EntityNode],
    edges: list[EntityEdge],
    limit: int = RELEVANT_SCHEMA_LIMIT,
) -> list[EpisodicNode]:
    episode_uuids: list[str] = []
    for edge in edges:
        episode_uuids.extend(edge.episodes)

    episodes = await EpisodicNode.get_by_uuids(driver, episode_uuids[:limit])

    return episodes


async def get_mentioned_nodes(
    driver: GraphDriver, episodes: list[EpisodicNode]
) -> list[EntityNode]:
    episode_uuids = [episode.uuid for episode in episodes]

    query = """
        MATCH (episode:Episodic)-[:MENTIONS]->(n:Entity) WHERE episode.uuid IN $uuids
        RETURN DISTINCT
            n.uuid As uuid, 
            n.group_id AS group_id,
            n.name AS name,
            n.created_at AS created_at, 
            n.summary AS summary,
            labels(n) AS labels,
            properties(n) AS attributes
        """

    records, _, _ = await driver.execute_query(
        query,
        uuids=episode_uuids,
        routing_='r',
    )

    nodes = [get_entity_node_from_record(record) for record in records]

    return nodes


async def get_communities_by_nodes(
    driver: GraphDriver, nodes: list[EntityNode]
) -> list[CommunityNode]:
    node_uuids = [node.uuid for node in nodes]

    query = """
    MATCH (c:Community)-[:HAS_MEMBER]->(n:Entity) WHERE n.uuid IN $uuids
    RETURN DISTINCT
        c.uuid As uuid, 
        c.group_id AS group_id,
        c.name AS name,
        c.created_at AS created_at, 
        c.summary AS summary
    """

    records, _, _ = await driver.execute_query(
        query,
        uuids=node_uuids,
        routing_='r',
    )

    communities = [get_community_node_from_record(record) for record in records]

    return communities


async def edge_fulltext_search(
    driver: GraphDriver,
    query: str,
    search_filter: SearchFilters,
    group_ids: list[str] | None = None,
    limit=RELEVANT_SCHEMA_LIMIT,
) -> list[EntityEdge]:
    # fulltext search over facts
    fuzzy_query = fulltext_query(query, group_ids, driver.fulltext_syntax)
    if fuzzy_query == '':
        return []

    filter_query, filter_params = edge_search_filter_query_constructor(search_filter)

    query = (
        get_relationships_query('edge_name_and_fact', db_type=driver.provider)
        + """
        YIELD relationship AS rel, score
        MATCH (n:Entity)-[r:RELATES_TO]->(m:Entity)
        WHERE r.group_id IN $group_ids """
        + filter_query
        + """
        WITH r, score, startNode(r) AS n, endNode(r) AS m
        RETURN
            r.uuid AS uuid,
            r.group_id AS group_id,
            n.uuid AS source_node_uuid,
            m.uuid AS target_node_uuid,
            r.created_at AS created_at,
            r.name AS name,
            r.fact AS fact,
            r.episodes AS episodes,
            r.expired_at AS expired_at,
            r.valid_at AS valid_at,
            r.invalid_at AS invalid_at,
            properties(r) AS attributes
        ORDER BY score DESC LIMIT $limit
        """
    )

    records, _, _ = await driver.execute_query(
        query,
        params=filter_params,
        query=fuzzy_query,
        group_ids=group_ids,
        limit=limit,
        routing_='r',
    )

    edges = [get_entity_edge_from_record(record) for record in records]

    return edges


async def edge_similarity_search(
    driver: GraphDriver,
    search_vector: list[float],
    source_node_uuid: str | None,
    target_node_uuid: str | None,
    search_filter: SearchFilters,
    group_ids: list[str] | None = None,
    limit: int = RELEVANT_SCHEMA_LIMIT,
    min_score: float = DEFAULT_MIN_SCORE,
) -> list[EntityEdge]:
    # vector similarity search over embedded facts
    query_params: dict[str, Any] = {}

    filter_query, filter_params = edge_search_filter_query_constructor(search_filter)
    query_params.update(filter_params)

    group_filter_query: LiteralString = 'WHERE r.group_id IS NOT NULL'
    if group_ids is not None:
        group_filter_query += '\nAND r.group_id IN $group_ids'
        query_params['group_ids'] = group_ids
        query_params['source_node_uuid'] = source_node_uuid
        query_params['target_node_uuid'] = target_node_uuid

        if source_node_uuid is not None:
            group_filter_query += '\nAND (n.uuid IN [$source_uuid, $target_uuid])'

        if target_node_uuid is not None:
            group_filter_query += '\nAND (m.uuid IN [$source_uuid, $target_uuid])'

    query = (
        RUNTIME_QUERY
        + """
        MATCH (n:Entity)-[r:RELATES_TO]->(m:Entity)
        """
        + group_filter_query
        + filter_query
        + """
        WITH DISTINCT r, """
        + get_vector_cosine_func_query('r.fact_embedding', '$search_vector', driver.provider)
        + """ AS score
        WHERE score > $min_score
        RETURN
            r.uuid AS uuid,
            r.group_id AS group_id,
            startNode(r).uuid AS source_node_uuid,
            endNode(r).uuid AS target_node_uuid,
            r.created_at AS created_at,
            r.name AS name,
            r.fact AS fact,
            r.episodes AS episodes,
            r.expired_at AS expired_at,
            r.valid_at AS valid_at,
            r.invalid_at AS invalid_at,
            properties(r) AS attributes
        ORDER BY score DESC
        LIMIT $limit
        """
    )
    records, header, _ = await driver.execute_query(
        query,
        params=query_params,
        search_vector=search_vector,
        source_uuid=source_node_uuid,
        target_uuid=target_node_uuid,
        group_ids=group_ids,
        limit=limit,
        min_score=min_score,
        routing_='r',
    )

    edges = [get_entity_edge_from_record(record) for record in records]

    return edges


async def edge_bfs_search(
    driver: GraphDriver,
    bfs_origin_node_uuids: list[str] | None,
    bfs_max_depth: int,
    search_filter: SearchFilters,
    limit: int,
) -> list[EntityEdge]:
    # vector similarity search over embedded facts
    if bfs_origin_node_uuids is None:
        return []

    filter_query, filter_params = edge_search_filter_query_constructor(search_filter)

    query = (
        """
                                    UNWIND $bfs_origin_node_uuids AS origin_uuid
                                    MATCH path = (origin:Entity|Episodic {uuid: origin_uuid})-[:RELATES_TO|MENTIONS]->{1,3}(n:Entity)
                                    UNWIND relationships(path) AS rel
                                    MATCH (n:Entity)-[r:RELATES_TO]-(m:Entity)
                                    WHERE r.uuid = rel.uuid
                                    """
        + filter_query
        + """  
                RETURN DISTINCT
                    r.uuid AS uuid,
                    r.group_id AS group_id,
                    startNode(r).uuid AS source_node_uuid,
                    endNode(r).uuid AS target_node_uuid,
                    r.created_at AS created_at,
                    r.name AS name,
                    r.fact AS fact,
                    r.episodes AS episodes,
                    r.expired_at AS expired_at,
                    r.valid_at AS valid_at,
                    r.invalid_at AS invalid_at,
                    properties(r) AS attributes
                LIMIT $limit
        """
    )

    records, _, _ = await driver.execute_query(
        query,
        params=filter_params,
        bfs_origin_node_uuids=bfs_origin_node_uuids,
        depth=bfs_max_depth,
        limit=limit,
        routing_='r',
    )

    edges = [get_entity_edge_from_record(record) for record in records]

    return edges


async def node_fulltext_search(
    driver: GraphDriver,
    query: str,
    search_filter: SearchFilters,
    group_ids: list[str] | None = None,
    limit=RELEVANT_SCHEMA_LIMIT,
) -> list[EntityNode]:
    # BM25 search to get top nodes
    fuzzy_query = fulltext_query(query, group_ids, driver.fulltext_syntax)
    if fuzzy_query == '':
        return []
    filter_query, filter_params = node_search_filter_query_constructor(search_filter)

    query = (
        get_nodes_query(driver.provider, 'node_name_and_summary', '$query')
        + """
        YIELD node AS n, score
            WITH n, score
            LIMIT $limit
            WHERE n:Entity
        """
        + filter_query
        + ENTITY_NODE_RETURN
        + """
        ORDER BY score DESC
        """
    )
    records, header, _ = await driver.execute_query(
        query,
        params=filter_params,
        query=fuzzy_query,
        group_ids=group_ids,
        limit=limit,
        routing_='r',
    )

    nodes = [get_entity_node_from_record(record) for record in records]

    return nodes


async def node_similarity_search(
    driver: GraphDriver,
    search_vector: list[float],
    search_filter: SearchFilters,
    group_ids: list[str] | None = None,
    limit=RELEVANT_SCHEMA_LIMIT,
    min_score: float = DEFAULT_MIN_SCORE,
) -> list[EntityNode]:
    # vector similarity search over entity names
    query_params: dict[str, Any] = {}

    group_filter_query: LiteralString = 'WHERE n.group_id IS NOT NULL'
    if group_ids is not None:
        group_filter_query += ' AND n.group_id IN $group_ids'
        query_params['group_ids'] = group_ids

    filter_query, filter_params = node_search_filter_query_constructor(search_filter)
    query_params.update(filter_params)

    query = (
        RUNTIME_QUERY
        + """
        MATCH (n:Entity)
        """
        + group_filter_query
        + filter_query
        + """
        WITH n, """
        + get_vector_cosine_func_query('n.name_embedding', '$search_vector', driver.provider)
        + """ AS score
        WHERE score > $min_score"""
        + ENTITY_NODE_RETURN
        + """
        ORDER BY score DESC
        LIMIT $limit
            """
    )

    records, header, _ = await driver.execute_query(
        query,
        params=query_params,
        search_vector=search_vector,
        group_ids=group_ids,
        limit=limit,
        min_score=min_score,
        routing_='r',
    )

    nodes = [get_entity_node_from_record(record) for record in records]

    return nodes


async def node_bfs_search(
    driver: GraphDriver,
    bfs_origin_node_uuids: list[str] | None,
    search_filter: SearchFilters,
    bfs_max_depth: int,
    limit: int,
) -> list[EntityNode]:
    # vector similarity search over entity names
    if bfs_origin_node_uuids is None:
        return []

    filter_query, filter_params = node_search_filter_query_constructor(search_filter)

    query = (
        """
                            UNWIND $bfs_origin_node_uuids AS origin_uuid
                            MATCH (origin:Entity|Episodic {uuid: origin_uuid})-[:RELATES_TO|MENTIONS]->{1,3}(n:Entity)
                            WHERE n.group_id = origin.group_id
                            """
        + filter_query
        + ENTITY_NODE_RETURN
        + """
        LIMIT $limit
        """
    )
    records, _, _ = await driver.execute_query(
        query,
        params=filter_params,
        bfs_origin_node_uuids=bfs_origin_node_uuids,
        depth=bfs_max_depth,
        limit=limit,
        routing_='r',
    )
    nodes = [get_entity_node_from_record(record) for record in records]

    return nodes


async def episode_fulltext_search(
    driver: GraphDriver,
    query: str,
    _search_filter: SearchFilters,
    group_ids: list[str] | None = None,
    limit=RELEVANT_SCHEMA_LIMIT,
) -> list[EpisodicNode]:
    # BM25 search to get top episodes
    fuzzy_query = fulltext_query(query, group_ids, driver.fulltext_syntax)
    if fuzzy_query == '':
        return []

    query = (
        get_nodes_query(driver.provider, 'episode_content', '$query')
        + """
        YIELD node AS episode, score
        MATCH (e:Episodic)
        WHERE e.uuid = episode.uuid
        RETURN 
            e.content AS content,
            e.created_at AS created_at,
            e.valid_at AS valid_at,
            e.uuid AS uuid,
            e.name AS name,
            e.group_id AS group_id,
            e.source_description AS source_description,
            e.source AS source,
            e.entity_edges AS entity_edges
        ORDER BY score DESC
        LIMIT $limit
        """
    )

    records, _, _ = await driver.execute_query(
        query,
        query=fuzzy_query,
        group_ids=group_ids,
        limit=limit,
        routing_='r',
    )
    episodes = [get_episodic_node_from_record(record) for record in records]

    return episodes


async def community_fulltext_search(
    driver: GraphDriver,
    query: str,
    group_ids: list[str] | None = None,
    limit=RELEVANT_SCHEMA_LIMIT,
) -> list[CommunityNode]:
    # BM25 search to get top communities
    fuzzy_query = fulltext_query(query, group_ids, driver.fulltext_syntax)
    if fuzzy_query == '':
        return []

    query = (
        get_nodes_query(driver.provider, 'community_name', '$query')
        + """
        YIELD node AS comm, score
        RETURN
            comm.uuid AS uuid,
            comm.group_id AS group_id, 
            comm.name AS name, 
            comm.created_at AS created_at, 
            comm.summary AS summary,
            comm.name_embedding AS name_embedding
        ORDER BY score DESC
        LIMIT $limit
        """
    )

    records, _, _ = await driver.execute_query(
        query,
        query=fuzzy_query,
        group_ids=group_ids,
        limit=limit,
        routing_='r',
    )
    communities = [get_community_node_from_record(record) for record in records]

    return communities


async def community_similarity_search(
    driver: GraphDriver,
    search_vector: list[float],
    group_ids: list[str] | None = None,
    limit=RELEVANT_SCHEMA_LIMIT,
    min_score=DEFAULT_MIN_SCORE,
) -> list[CommunityNode]:
    # vector similarity search over entity names
    query_params: dict[str, Any] = {}

    group_filter_query: LiteralString = ''
    if group_ids is not None:
        group_filter_query += 'WHERE comm.group_id IN $group_ids'
        query_params['group_ids'] = group_ids

    query = (
        RUNTIME_QUERY
        + """
           MATCH (comm:Community)
           """
        + group_filter_query
        + """
           WITH comm, """
        + get_vector_cosine_func_query('comm.name_embedding', '$search_vector', driver.provider)
        + """ AS score
           WHERE score > $min_score
           RETURN
               comm.uuid As uuid,
               comm.group_id AS group_id,
               comm.name AS name, 
               comm.created_at AS created_at, 
               comm.summary AS summary,
               comm.name_embedding AS name_embedding
           ORDER BY score DESC
           LIMIT $limit
        """
    )

    records, _, _ = await driver.execute_query(
        query,
        search_vector=search_vector,
        group_ids=group_ids,
        limit=limit,
        min_score=min_score,
        routing_='r',
    )
    communities = [get_community_node_from_record(record) for record in records]

    return communities


async def hybrid_node_search(
    queries: list[str],
    embeddings: list[list[float]],
    driver: GraphDriver,
    search_filter: SearchFilters,
    group_ids: list[str] | None = None,
    limit: int = RELEVANT_SCHEMA_LIMIT,
) -> list[EntityNode]:
    """
    Perform a hybrid search for nodes using both text queries and embeddings.

    This method combines fulltext search and vector similarity search to find
    relevant nodes in the graph database. It uses a rrf reranker.

    Parameters
    ----------
    queries : list[str]
        A list of text queries to search for.
    embeddings : list[list[float]]
        A list of embedding vectors corresponding to the queries. If empty only fulltext search is performed.
    driver : GraphDriver
        The Neo4j driver instance for database operations.
    group_ids : list[str] | None, optional
        The list of group ids to retrieve nodes from.
    limit : int | None, optional
        The maximum number of results to return per search method. If None, a default limit will be applied.

    Returns
    -------
    list[EntityNode]
        A list of unique EntityNode objects that match the search criteria.

    Notes
    -----
    This method performs the following steps:
    1. Executes fulltext searches for each query.
    2. Executes vector similarity searches for each embedding.
    3. Combines and deduplicates the results from both search types.
    4. Logs the performance metrics of the search operation.

    The search results are deduplicated based on the node UUIDs to ensure
    uniqueness in the returned list. The 'limit' parameter is applied to each
    individual search method before deduplication. If not specified, a default
    limit (defined in the individual search functions) will be used.
    """

    start = time()
    results: list[list[EntityNode]] = list(
        await semaphore_gather(
            *[
                node_fulltext_search(driver, q, search_filter, group_ids, 2 * limit)
                for q in queries
            ],
            *[
                node_similarity_search(driver, e, search_filter, group_ids, 2 * limit)
                for e in embeddings
            ],
        )
    )

    node_uuid_map: dict[str, EntityNode] = {
        node.uuid: node for result in results for node in result
    }
    result_uuids = [[node.uuid for node in result] for result in results]

    ranked_uuids = rrf(result_uuids)

    relevant_nodes: list[EntityNode] = [node_uuid_map[uuid] for uuid in ranked_uuids]

    end = time()
    logger.debug(f'Found relevant nodes: {ranked_uuids} in {(end - start) * 1000} ms')
    return relevant_nodes


async def get_relevant_nodes(
    driver: GraphDriver,
    nodes: list[EntityNode],
    search_filter: SearchFilters,
    min_score: float = DEFAULT_MIN_SCORE,
    limit: int = RELEVANT_SCHEMA_LIMIT,
) -> list[list[EntityNode]]:
    if len(nodes) == 0:
        return []

    group_id = nodes[0].group_id

    # vector similarity search over entity names
    query_params: dict[str, Any] = {}

    filter_query, filter_params = node_search_filter_query_constructor(search_filter)
    query_params.update(filter_params)

    query = (
        RUNTIME_QUERY
        + """
        UNWIND $nodes AS node
        MATCH (n:Entity {group_id: $group_id})
        """
        + filter_query
        + """
        WITH node, n, """
        + get_vector_cosine_func_query('n.name_embedding', 'node.name_embedding', driver.provider)
        + """ AS score
        WHERE score > $min_score
        WITH node, collect(n)[..$limit] AS top_vector_nodes, collect(n.uuid) AS vector_node_uuids
        """
        + get_nodes_query(driver.provider, 'node_name_and_summary', 'node.fulltext_query')
        + """
        YIELD node AS m
        WHERE m.group_id = $group_id
        WITH node, top_vector_nodes, vector_node_uuids, collect(m) AS fulltext_nodes

        WITH node, 
             top_vector_nodes, 
             [m IN fulltext_nodes WHERE NOT m.uuid IN vector_node_uuids] AS filtered_fulltext_nodes

        WITH node, top_vector_nodes + filtered_fulltext_nodes AS combined_nodes

        UNWIND combined_nodes AS combined_node
        WITH node, collect(DISTINCT combined_node) AS deduped_nodes

        RETURN 
          node.uuid AS search_node_uuid,
          [x IN deduped_nodes | {
            uuid: x.uuid, 
            name: x.name,
            name_embedding: x.name_embedding,
            group_id: x.group_id,
            created_at: x.created_at,
            summary: x.summary,
            labels: labels(x),
            attributes: properties(x)
          }] AS matches
        """
    )

    query_nodes = [
        {
            'uuid': node.uuid,
            'name': node.name,
            'name_embedding': node.name_embedding,
            'fulltext_query': fulltext_query(node.name, [node.group_id], driver.fulltext_syntax),
        }
        for node in nodes
    ]

    results, _, _ = await driver.execute_query(
        query,
        params=query_params,
        nodes=query_nodes,
        group_id=group_id,
        limit=limit,
        min_score=min_score,
        routing_='r',
    )

    relevant_nodes_dict: dict[str, list[EntityNode]] = {
        result['search_node_uuid']: [
            get_entity_node_from_record(record) for record in result['matches']
        ]
        for result in results
    }

    relevant_nodes = [relevant_nodes_dict.get(node.uuid, []) for node in nodes]

    return relevant_nodes


async def get_relevant_edges(
    driver: GraphDriver,
    edges: list[EntityEdge],
    search_filter: SearchFilters,
    min_score: float = DEFAULT_MIN_SCORE,
    limit: int = RELEVANT_SCHEMA_LIMIT,
) -> list[list[EntityEdge]]:
    if len(edges) == 0:
        return []

    query_params: dict[str, Any] = {}

    filter_query, filter_params = edge_search_filter_query_constructor(search_filter)
    query_params.update(filter_params)

    query = (
        RUNTIME_QUERY
        + """
        UNWIND $edges AS edge
        MATCH (n:Entity {uuid: edge.source_node_uuid})-[e:RELATES_TO {group_id: edge.group_id}]-(m:Entity {uuid: edge.target_node_uuid})
        """
        + filter_query
        + """
        WITH e, edge, """
        + get_vector_cosine_func_query('e.fact_embedding', 'edge.fact_embedding', driver.provider)
        + """ AS score
        WHERE score > $min_score
        WITH edge, e, score
        ORDER BY score DESC
        RETURN edge.uuid AS search_edge_uuid,
            collect({
                uuid: e.uuid,
                source_node_uuid: startNode(e).uuid,
                target_node_uuid: endNode(e).uuid,
                created_at: e.created_at,
                name: e.name,
                group_id: e.group_id,
                fact: e.fact,
                fact_embedding: e.fact_embedding,
                episodes: e.episodes,
                expired_at: e.expired_at,
                valid_at: e.valid_at,
                invalid_at: e.invalid_at,
                attributes: properties(e)
            })[..$limit] AS matches
        """
    )

    results, _, _ = await driver.execute_query(
        query,
        params=query_params,
        edges=[edge.model_dump() for edge in edges],
        limit=limit,
        min_score=min_score,
        routing_='r',
    )

    relevant_edges_dict: dict[str, list[EntityEdge]] = {
        result['search_edge_uuid']: [
            get_entity_edge_from_record(record) for record in result['matches']
        ]
        for result in results
    }

    relevant_edges = [relevant_edges_dict.get(edge.uuid, []) for edge in edges]

    return relevant_edges


async def get_edge_invalidation_candidates(
    driver: GraphDriver,
    edges: list[EntityEdge],
    search_filter: SearchFilters,
    min_score: float = DEFAULT_MIN_SCORE,
    limit: int = RELEVANT_SCHEMA_LIMIT,
) -> list[list[EntityEdge]]:
    if len(edges) == 0:
        return []

    query_params: dict[str, Any] = {}

    filter_query, filter_params = edge_search_filter_query_constructor(search_filter)
    query_params.update(filter_params)

    query = (
        RUNTIME_QUERY
        + """
        UNWIND $edges AS edge
        MATCH (n:Entity)-[e:RELATES_TO {group_id: edge.group_id}]->(m:Entity)
        WHERE n.uuid IN [edge.source_node_uuid, edge.target_node_uuid] OR m.uuid IN [edge.target_node_uuid, edge.source_node_uuid]
        """
        + filter_query
        + """
        WITH edge, e, """
        + get_vector_cosine_func_query('e.fact_embedding', 'edge.fact_embedding', driver.provider)
        + """ AS score
        WHERE score > $min_score
        WITH edge, e, score
        ORDER BY score DESC
        RETURN edge.uuid AS search_edge_uuid,
            collect({
                uuid: e.uuid,
                source_node_uuid: startNode(e).uuid,
                target_node_uuid: endNode(e).uuid,
                created_at: e.created_at,
                name: e.name,
                group_id: e.group_id,
                fact: e.fact,
                fact_embedding: e.fact_embedding,
                episodes: e.episodes,
                expired_at: e.expired_at,
                valid_at: e.valid_at,
                invalid_at: e.invalid_at,
                attributes: properties(e)
            })[..$limit] AS matches
        """
    )

    results, _, _ = await driver.execute_query(
        query,
        params=query_params,
        edges=[edge.model_dump() for edge in edges],
        limit=limit,
        min_score=min_score,
        routing_='r',
    )
    invalidation_edges_dict: dict[str, list[EntityEdge]] = {
        result['search_edge_uuid']: [
            get_entity_edge_from_record(record) for record in result['matches']
        ]
        for result in results
    }

    invalidation_edges = [invalidation_edges_dict.get(edge.uuid, []) for edge in edges]

    return invalidation_edges


# takes in a list of rankings of uuids
def rrf(results: list[list[str]], rank_const=1, min_score: float = 0) -> list[str]:
    scores: dict[str, float] = defaultdict(float)
    for result in results:
        for i, uuid in enumerate(result):
            scores[uuid] += 1 / (i + rank_const)

    scored_uuids = [term for term in scores.items()]
    scored_uuids.sort(reverse=True, key=lambda term: term[1])

    sorted_uuids = [term[0] for term in scored_uuids]

    return [uuid for uuid in sorted_uuids if scores[uuid] >= min_score]


async def node_distance_reranker(
    driver: GraphDriver,
    node_uuids: list[str],
    center_node_uuid: str,
    min_score: float = 0,
) -> list[str]:
    # filter out node_uuid center node node uuid
    filtered_uuids = list(filter(lambda node_uuid: node_uuid != center_node_uuid, node_uuids))
    scores: dict[str, float] = {center_node_uuid: 0.0}

    # Find the shortest path to center node
    query = """
        UNWIND $node_uuids AS node_uuid
        MATCH (center:Entity {uuid: $center_uuid})-[:RELATES_TO]-(n:Entity {uuid: node_uuid})
        RETURN 1 AS score, node_uuid AS uuid
        """
    results, header, _ = await driver.execute_query(
        query,
        node_uuids=filtered_uuids,
        center_uuid=center_node_uuid,
        routing_='r',
    )
    if driver.provider == 'falkordb':
        results = [dict(zip(header, row, strict=True)) for row in results]

    for result in results:
        uuid = result['uuid']
        score = result['score']
        scores[uuid] = score

    for uuid in filtered_uuids:
        if uuid not in scores:
            scores[uuid] = float('inf')

    # rerank on shortest distance
    filtered_uuids.sort(key=lambda cur_uuid: scores[cur_uuid])

    # add back in filtered center uuid if it was filtered out
    if center_node_uuid in node_uuids:
        scores[center_node_uuid] = 0.1
        filtered_uuids = [center_node_uuid] + filtered_uuids

    return [uuid for uuid in filtered_uuids if (1 / scores[uuid]) >= min_score]


async def episode_mentions_reranker(
    driver: GraphDriver, node_uuids: list[list[str]], min_score: float = 0
) -> list[str]:
    # use rrf as a preliminary ranker
    sorted_uuids = rrf(node_uuids)
    scores: dict[str, float] = {}

    # Find the shortest path to center node
    query = """
        UNWIND $node_uuids AS node_uuid 
        MATCH (episode:Episodic)-[r:MENTIONS]->(n:Entity {uuid: node_uuid})
        RETURN count(*) AS score, n.uuid AS uuid
        """
    results, _, _ = await driver.execute_query(
        query,
        node_uuids=sorted_uuids,
        routing_='r',
    )

    for result in results:
        scores[result['uuid']] = result['score']

    # rerank on shortest distance
    sorted_uuids.sort(key=lambda cur_uuid: scores[cur_uuid])

    return [uuid for uuid in sorted_uuids if scores[uuid] >= min_score]


def normalize_embeddings_batch(embeddings: NDArray) -> NDArray:
    """
    Normalize a batch of embeddings using L2 normalization.
    
    Args:
        embeddings: Array of shape (n_embeddings, embedding_dim)
    
    Returns:
        L2-normalized embeddings of same shape
    """
    norms = np.linalg.norm(embeddings, axis=1, keepdims=True)
    # Avoid division by zero
    norms = np.where(norms == 0, 1, norms)
    return embeddings / norms


def maximal_marginal_relevance(
    query_vector: list[float],
    candidates: dict[str, list[float]],
    mmr_lambda: float = DEFAULT_MMR_LAMBDA,
    min_score: float = -2.0,
    max_results: int | None = None,
) -> list[str]:
    """
    Optimized implementation of Maximal Marginal Relevance (MMR) using vectorized numpy operations.
    
    This implementation:
    1. Uses true iterative MMR algorithm (greedy selection)
    2. Leverages vectorized numpy operations for performance
    3. Normalizes query vector for consistent similarity computation
    4. Minimizes memory usage by avoiding full similarity matrices
    5. Leverages optimized BLAS operations through matrix multiplication
    6. Optimizes for small datasets by using efficient numpy operations
    
    Args:
        query_vector: Query embedding vector
        candidates: Dictionary mapping UUIDs to embedding vectors
        mmr_lambda: Balance parameter between relevance and diversity (0-1)
        min_score: Minimum MMR score threshold
        max_results: Maximum number of results to return
    
    Returns:
        List of candidate UUIDs ranked by MMR score
    """
    start = time()
    
    if not candidates:
        return []
    
    # Convert to numpy arrays for vectorized operations
    uuids = list(candidates.keys())
    candidate_embeddings = np.array([candidates[uuid] for uuid in uuids])
    
    # Normalize all embeddings (query and candidates) for cosine similarity
    candidate_embeddings = normalize_embeddings_batch(candidate_embeddings)
    query_normalized = normalize_l2(query_vector)
    
    # Compute relevance scores (query-candidate similarities) using matrix multiplication
    relevance_scores = candidate_embeddings @ query_normalized  # Shape: (n_candidates,)
    
    # For small datasets, use optimized batch computation
    if len(uuids) <= 100:
        return _mmr_small_dataset(uuids, candidate_embeddings, relevance_scores, mmr_lambda, min_score, max_results)
    
    # For large datasets, use iterative selection to save memory
    selected_indices = []
    remaining_indices = set(range(len(uuids)))
    
    max_results = max_results or len(uuids)
    
    for _ in range(min(max_results, len(uuids))):
        if not remaining_indices:
            break
            
        best_idx = None
        best_score = -float('inf')
        
        # Vectorized computation of MMR scores for all remaining candidates
        remaining_list = list(remaining_indices)
        remaining_relevance = relevance_scores[remaining_list]
        
        if selected_indices:
            # Compute similarities between remaining candidates and selected documents
            remaining_embeddings = candidate_embeddings[remaining_list]  # Shape: (n_remaining, dim)
            selected_embeddings = candidate_embeddings[selected_indices]  # Shape: (n_selected, dim)
            
            # Matrix multiplication: (n_remaining, dim) @ (dim, n_selected) = (n_remaining, n_selected)
            sim_matrix = remaining_embeddings @ selected_embeddings.T
            diversity_penalties = np.max(sim_matrix, axis=1)  # Max similarity to any selected doc
        else:
            diversity_penalties = np.zeros(len(remaining_list))
        
        # Compute MMR scores for all remaining candidates
        mmr_scores = mmr_lambda * remaining_relevance - (1 - mmr_lambda) * diversity_penalties
        
        # Find best candidate
        best_local_idx = np.argmax(mmr_scores)
        best_score = mmr_scores[best_local_idx]
        
        if best_score >= min_score:
            best_idx = remaining_list[best_local_idx]
            selected_indices.append(best_idx)
            remaining_indices.remove(best_idx)
        else:
            break
    
    end = time()
    logger.debug(f'Completed optimized MMR reranking in {(end - start) * 1000} ms')
    
    return [uuids[idx] for idx in selected_indices]


def _mmr_small_dataset(
    uuids: list[str],
    candidate_embeddings: NDArray,
    relevance_scores: NDArray,
    mmr_lambda: float,
    min_score: float,
    max_results: int | None,
) -> list[str]:
    """
    Optimized MMR implementation for small datasets using precomputed similarity matrix.
    """
    n_candidates = len(uuids)
    max_results = max_results or n_candidates
    
    # Precompute similarity matrix for small datasets
    similarity_matrix = candidate_embeddings @ candidate_embeddings.T  # Shape: (n, n)
    
    selected_indices = []
    remaining_indices = set(range(n_candidates))
    
    for _ in range(min(max_results, n_candidates)):
        if not remaining_indices:
            break
            
        best_idx = None
        best_score = -float('inf')
        
        for idx in remaining_indices:
            relevance = relevance_scores[idx]
            
            # Compute diversity penalty using precomputed matrix
            if selected_indices:
                diversity_penalty = np.max(similarity_matrix[idx, selected_indices])
            else:
                diversity_penalty = 0.0
            
            # MMR score
            mmr_score = mmr_lambda * relevance - (1 - mmr_lambda) * diversity_penalty
            
            if mmr_score > best_score:
                best_score = mmr_score
                best_idx = idx
        
        if best_idx is not None and best_score >= min_score:
            selected_indices.append(best_idx)
            remaining_indices.remove(best_idx)
        else:
            break
    
    return [uuids[idx] for idx in selected_indices]


async def get_embeddings_for_nodes(
    driver: GraphDriver, nodes: list[EntityNode]
) -> dict[str, list[float]]:
    query: LiteralString = """MATCH (n:Entity)
                              WHERE n.uuid IN $node_uuids
                              RETURN DISTINCT
                                n.uuid AS uuid,
                                n.name_embedding AS name_embedding
                    """

    results, _, _ = await driver.execute_query(
        query, node_uuids=[node.uuid for node in nodes], routing_='r'
    )

    embeddings_dict: dict[str, list[float]] = {}
    for result in results:
        uuid: str = result.get('uuid')
        embedding: list[float] = result.get('name_embedding')
        if uuid is not None and embedding is not None:
            embeddings_dict[uuid] = embedding

    return embeddings_dict


async def get_embeddings_for_communities(
    driver: GraphDriver, communities: list[CommunityNode]
) -> dict[str, list[float]]:
    query: LiteralString = """MATCH (c:Community)
                              WHERE c.uuid IN $community_uuids
                              RETURN DISTINCT
                                c.uuid AS uuid,
                                c.name_embedding AS name_embedding
                    """

    results, _, _ = await driver.execute_query(
        query,
        community_uuids=[community.uuid for community in communities],
        routing_='r',
    )

    embeddings_dict: dict[str, list[float]] = {}
    for result in results:
        uuid: str = result.get('uuid')
        embedding: list[float] = result.get('name_embedding')
        if uuid is not None and embedding is not None:
            embeddings_dict[uuid] = embedding

    return embeddings_dict


async def get_embeddings_for_edges(
    driver: GraphDriver, edges: list[EntityEdge]
) -> dict[str, list[float]]:
    query: LiteralString = """MATCH (n:Entity)-[e:RELATES_TO]-(m:Entity)
                              WHERE e.uuid IN $edge_uuids
                              RETURN DISTINCT
                                e.uuid AS uuid,
                                e.fact_embedding AS fact_embedding
                    """

    results, _, _ = await driver.execute_query(
        query,
        edge_uuids=[edge.uuid for edge in edges],
        routing_='r',
    )

    embeddings_dict: dict[str, list[float]] = {}
    for result in results:
        uuid: str = result.get('uuid')
        embedding: list[float] = result.get('fact_embedding')
        if uuid is not None and embedding is not None:
            embeddings_dict[uuid] = embedding

    return embeddings_dict