Files
t6_mem0/mem0/vector_stores/pgvector.py
2025-05-22 01:17:29 +05:30

295 lines
9.3 KiB
Python

import json
import logging
from typing import List, Optional
from pydantic import BaseModel
try:
import psycopg2
from psycopg2.extras import execute_values
except ImportError:
raise ImportError("The 'psycopg2' library is required. Please install it using 'pip install psycopg2'.")
from mem0.vector_stores.base import VectorStoreBase
logger = logging.getLogger(__name__)
class OutputData(BaseModel):
id: Optional[str]
score: Optional[float]
payload: Optional[dict]
class PGVector(VectorStoreBase):
def __init__(
self,
dbname,
collection_name,
embedding_model_dims,
user,
password,
host,
port,
diskann,
hnsw,
):
"""
Initialize the PGVector database.
Args:
dbname (str): Database name
collection_name (str): Collection name
embedding_model_dims (int): Dimension of the embedding vector
user (str): Database user
password (str): Database password
host (str, optional): Database host
port (int, optional): Database port
diskann (bool, optional): Use DiskANN for faster search
hnsw (bool, optional): Use HNSW for faster search
"""
self.collection_name = collection_name
self.use_diskann = diskann
self.use_hnsw = hnsw
self.embedding_model_dims = embedding_model_dims
self.conn = psycopg2.connect(dbname=dbname, user=user, password=password, host=host, port=port)
self.cur = self.conn.cursor()
collections = self.list_cols()
if collection_name not in collections:
self.create_col(embedding_model_dims)
def create_col(self, embedding_model_dims):
"""
Create a new collection (table in PostgreSQL).
Will also initialize vector search index if specified.
Args:
embedding_model_dims (int): Dimension of the embedding vector.
"""
self.cur.execute("CREATE EXTENSION IF NOT EXISTS vector")
self.cur.execute(
f"""
CREATE TABLE IF NOT EXISTS {self.collection_name} (
id UUID PRIMARY KEY,
vector vector({embedding_model_dims}),
payload JSONB
);
"""
)
if self.use_diskann and embedding_model_dims < 2000:
# Check if vectorscale extension is installed
self.cur.execute("SELECT * FROM pg_extension WHERE extname = 'vectorscale'")
if self.cur.fetchone():
# Create DiskANN index if extension is installed for faster search
self.cur.execute(
f"""
CREATE INDEX IF NOT EXISTS {self.collection_name}_diskann_idx
ON {self.collection_name}
USING diskann (vector);
"""
)
elif self.use_hnsw:
self.cur.execute(
f"""
CREATE INDEX IF NOT EXISTS {self.collection_name}_hnsw_idx
ON {self.collection_name}
USING hnsw (vector vector_cosine_ops)
"""
)
self.conn.commit()
def insert(self, vectors, payloads=None, ids=None):
"""
Insert vectors into a collection.
Args:
vectors (List[List[float]]): List of vectors to insert.
payloads (List[Dict], optional): List of payloads corresponding to vectors.
ids (List[str], optional): List of IDs corresponding to vectors.
"""
logger.info(f"Inserting {len(vectors)} vectors into collection {self.collection_name}")
json_payloads = [json.dumps(payload) for payload in payloads]
data = [(id, vector, payload) for id, vector, payload in zip(ids, vectors, json_payloads)]
execute_values(
self.cur,
f"INSERT INTO {self.collection_name} (id, vector, payload) VALUES %s",
data,
)
self.conn.commit()
def search(self, query, vectors, limit=5, filters=None):
"""
Search for similar vectors.
Args:
query (str): Query.
vectors (List[float]): Query vector.
limit (int, optional): Number of results to return. Defaults to 5.
filters (Dict, optional): Filters to apply to the search. Defaults to None.
Returns:
list: Search results.
"""
filter_conditions = []
filter_params = []
if filters:
for k, v in filters.items():
filter_conditions.append("payload->>%s = %s")
filter_params.extend([k, str(v)])
filter_clause = "WHERE " + " AND ".join(filter_conditions) if filter_conditions else ""
self.cur.execute(
f"""
SELECT id, vector <=> %s::vector AS distance, payload
FROM {self.collection_name}
{filter_clause}
ORDER BY distance
LIMIT %s
""",
(vectors, *filter_params, limit),
)
results = self.cur.fetchall()
return [OutputData(id=str(r[0]), score=float(r[1]), payload=r[2]) for r in results]
def delete(self, vector_id):
"""
Delete a vector by ID.
Args:
vector_id (str): ID of the vector to delete.
"""
self.cur.execute(f"DELETE FROM {self.collection_name} WHERE id = %s", (vector_id,))
self.conn.commit()
def update(self, vector_id, vector=None, payload=None):
"""
Update a vector and its payload.
Args:
vector_id (str): ID of the vector to update.
vector (List[float], optional): Updated vector.
payload (Dict, optional): Updated payload.
"""
if vector:
self.cur.execute(
f"UPDATE {self.collection_name} SET vector = %s WHERE id = %s",
(vector, vector_id),
)
if payload:
self.cur.execute(
f"UPDATE {self.collection_name} SET payload = %s WHERE id = %s",
(psycopg2.extras.Json(payload), vector_id),
)
self.conn.commit()
def get(self, vector_id) -> OutputData:
"""
Retrieve a vector by ID.
Args:
vector_id (str): ID of the vector to retrieve.
Returns:
OutputData: Retrieved vector.
"""
self.cur.execute(
f"SELECT id, vector, payload FROM {self.collection_name} WHERE id = %s",
(vector_id,),
)
result = self.cur.fetchone()
if not result:
return None
return OutputData(id=str(result[0]), score=None, payload=result[2])
def list_cols(self) -> List[str]:
"""
List all collections.
Returns:
List[str]: List of collection names.
"""
self.cur.execute("SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'")
return [row[0] for row in self.cur.fetchall()]
def delete_col(self):
"""Delete a collection."""
self.cur.execute(f"DROP TABLE IF EXISTS {self.collection_name}")
self.conn.commit()
def col_info(self):
"""
Get information about a collection.
Returns:
Dict[str, Any]: Collection information.
"""
self.cur.execute(
f"""
SELECT
table_name,
(SELECT COUNT(*) FROM {self.collection_name}) as row_count,
(SELECT pg_size_pretty(pg_total_relation_size('{self.collection_name}'))) as total_size
FROM information_schema.tables
WHERE table_schema = 'public' AND table_name = %s
""",
(self.collection_name,),
)
result = self.cur.fetchone()
return {"name": result[0], "count": result[1], "size": result[2]}
def list(self, filters=None, limit=100):
"""
List all vectors in a collection.
Args:
filters (Dict, optional): Filters to apply to the list.
limit (int, optional): Number of vectors to return. Defaults to 100.
Returns:
List[OutputData]: List of vectors.
"""
filter_conditions = []
filter_params = []
if filters:
for k, v in filters.items():
filter_conditions.append("payload->>%s = %s")
filter_params.extend([k, str(v)])
filter_clause = "WHERE " + " AND ".join(filter_conditions) if filter_conditions else ""
query = f"""
SELECT id, vector, payload
FROM {self.collection_name}
{filter_clause}
LIMIT %s
"""
self.cur.execute(query, (*filter_params, limit))
results = self.cur.fetchall()
return [[OutputData(id=str(r[0]), score=None, payload=r[2]) for r in results]]
def __del__(self):
"""
Close the database connection when the object is deleted.
"""
if hasattr(self, "cur"):
self.cur.close()
if hasattr(self, "conn"):
self.conn.close()
def reset(self):
"""Reset the index by deleting and recreating it."""
logger.warning(f"Resetting index {self.collection_name}...")
self.delete_col()
self.create_col(self.embedding_model_dims)