Files
project-lyra/neomem/neomem/vector_stores/pgvector.py
2025-11-16 03:17:32 -05:00

405 lines
14 KiB
Python

import json
import logging
from contextlib import contextmanager
from typing import Any, List, Optional
from pydantic import BaseModel
# Try to import psycopg (psycopg3) first, then fall back to psycopg2
try:
from psycopg.types.json import Json
from psycopg_pool import ConnectionPool
PSYCOPG_VERSION = 3
logger = logging.getLogger(__name__)
logger.info("Using psycopg (psycopg3) with ConnectionPool for PostgreSQL connections")
except ImportError:
try:
from psycopg2.extras import Json, execute_values
from psycopg2.pool import ThreadedConnectionPool as ConnectionPool
PSYCOPG_VERSION = 2
logger = logging.getLogger(__name__)
logger.info("Using psycopg2 with ThreadedConnectionPool for PostgreSQL connections")
except ImportError:
raise ImportError(
"Neither 'psycopg' nor 'psycopg2' library is available. "
"Please install one of them using 'pip install psycopg[pool]' or 'pip install psycopg2'"
)
from neomem.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,
minconn=1,
maxconn=5,
sslmode=None,
connection_string=None,
connection_pool=None,
):
"""
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
minconn (int): Minimum number of connections to keep in the connection pool
maxconn (int): Maximum number of connections allowed in the connection pool
sslmode (str, optional): SSL mode for PostgreSQL connection (e.g., 'require', 'prefer', 'disable')
connection_string (str, optional): PostgreSQL connection string (overrides individual connection parameters)
connection_pool (Any, optional): psycopg2 connection pool object (overrides connection string and individual parameters)
"""
self.collection_name = collection_name
self.use_diskann = diskann
self.use_hnsw = hnsw
self.embedding_model_dims = embedding_model_dims
self.connection_pool = None
# Connection setup with priority: connection_pool > connection_string > individual parameters
if connection_pool is not None:
# Use provided connection pool
self.connection_pool = connection_pool
elif connection_string:
if sslmode:
# Append sslmode to connection string if provided
if 'sslmode=' in connection_string:
# Replace existing sslmode
import re
connection_string = re.sub(r'sslmode=[^ ]*', f'sslmode={sslmode}', connection_string)
else:
# Add sslmode to connection string
connection_string = f"{connection_string} sslmode={sslmode}"
else:
connection_string = f"postgresql://{user}:{password}@{host}:{port}/{dbname}"
if sslmode:
connection_string = f"{connection_string} sslmode={sslmode}"
if self.connection_pool is None:
if PSYCOPG_VERSION == 3:
# psycopg3 ConnectionPool
self.connection_pool = ConnectionPool(conninfo=connection_string, min_size=minconn, max_size=maxconn, open=True)
else:
# psycopg2 ThreadedConnectionPool
self.connection_pool = ConnectionPool(minconn=minconn, maxconn=maxconn, dsn=connection_string)
collections = self.list_cols()
if collection_name not in collections:
self.create_col()
@contextmanager
def _get_cursor(self, commit: bool = False):
"""
Unified context manager to get a cursor from the appropriate pool.
Auto-commits or rolls back based on exception, and returns the connection to the pool.
"""
if PSYCOPG_VERSION == 3:
# psycopg3 auto-manages commit/rollback and pool return
with self.connection_pool.connection() as conn:
with conn.cursor() as cur:
try:
yield cur
if commit:
conn.commit()
except Exception:
conn.rollback()
logger.error("Error in cursor context (psycopg3)", exc_info=True)
raise
else:
# psycopg2 manual getconn/putconn
conn = self.connection_pool.getconn()
cur = conn.cursor()
try:
yield cur
if commit:
conn.commit()
except Exception as exc:
conn.rollback()
logger.error(f"Error occurred: {exc}")
raise exc
finally:
cur.close()
self.connection_pool.putconn(conn)
def create_col(self) -> None:
"""
Create a new collection (table in PostgreSQL).
Will also initialize vector search index if specified.
"""
with self._get_cursor(commit=True) as cur:
cur.execute("CREATE EXTENSION IF NOT EXISTS vector")
cur.execute(
f"""
CREATE TABLE IF NOT EXISTS {self.collection_name} (
id UUID PRIMARY KEY,
vector vector({self.embedding_model_dims}),
payload JSONB
);
"""
)
if self.use_diskann and self.embedding_model_dims < 2000:
cur.execute("SELECT * FROM pg_extension WHERE extname = 'vectorscale'")
if cur.fetchone():
# Create DiskANN index if extension is installed for faster search
cur.execute(
f"""
CREATE INDEX IF NOT EXISTS {self.collection_name}_diskann_idx
ON {self.collection_name}
USING diskann (vector);
"""
)
elif self.use_hnsw:
cur.execute(
f"""
CREATE INDEX IF NOT EXISTS {self.collection_name}_hnsw_idx
ON {self.collection_name}
USING hnsw (vector vector_cosine_ops)
"""
)
def insert(self, vectors: list[list[float]], payloads=None, ids=None) -> None:
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)]
if PSYCOPG_VERSION == 3:
with self._get_cursor(commit=True) as cur:
cur.executemany(
f"INSERT INTO {self.collection_name} (id, vector, payload) VALUES (%s, %s, %s)",
data,
)
else:
with self._get_cursor(commit=True) as cur:
execute_values(
cur,
f"INSERT INTO {self.collection_name} (id, vector, payload) VALUES %s",
data,
)
def search(
self,
query: str,
vectors: list[float],
limit: Optional[int] = 5,
filters: Optional[dict] = None,
) -> List[OutputData]:
"""
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 ""
with self._get_cursor() as cur:
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 = cur.fetchall()
return [OutputData(id=str(r[0]), score=float(r[1]), payload=r[2]) for r in results]
def delete(self, vector_id: str) -> None:
"""
Delete a vector by ID.
Args:
vector_id (str): ID of the vector to delete.
"""
with self._get_cursor(commit=True) as cur:
cur.execute(f"DELETE FROM {self.collection_name} WHERE id = %s", (vector_id,))
def update(
self,
vector_id: str,
vector: Optional[list[float]] = None,
payload: Optional[dict] = None,
) -> 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.
"""
with self._get_cursor(commit=True) as cur:
if vector:
cur.execute(
f"UPDATE {self.collection_name} SET vector = %s WHERE id = %s",
(vector, vector_id),
)
if payload:
# Handle JSON serialization based on psycopg version
if PSYCOPG_VERSION == 3:
# psycopg3 uses psycopg.types.json.Json
cur.execute(
f"UPDATE {self.collection_name} SET payload = %s WHERE id = %s",
(Json(payload), vector_id),
)
else:
# psycopg2 uses psycopg2.extras.Json
cur.execute(
f"UPDATE {self.collection_name} SET payload = %s WHERE id = %s",
(Json(payload), vector_id),
)
def get(self, vector_id: str) -> OutputData:
"""
Retrieve a vector by ID.
Args:
vector_id (str): ID of the vector to retrieve.
Returns:
OutputData: Retrieved vector.
"""
with self._get_cursor() as cur:
cur.execute(
f"SELECT id, vector, payload FROM {self.collection_name} WHERE id = %s",
(vector_id,),
)
result = 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.
"""
with self._get_cursor() as cur:
cur.execute("SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'")
return [row[0] for row in cur.fetchall()]
def delete_col(self) -> None:
"""Delete a collection."""
with self._get_cursor(commit=True) as cur:
cur.execute(f"DROP TABLE IF EXISTS {self.collection_name}")
def col_info(self) -> dict[str, Any]:
"""
Get information about a collection.
Returns:
Dict[str, Any]: Collection information.
"""
with self._get_cursor() as cur:
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 = cur.fetchone()
return {"name": result[0], "count": result[1], "size": result[2]}
def list(
self,
filters: Optional[dict] = None,
limit: Optional[int] = 100
) -> List[OutputData]:
"""
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
"""
with self._get_cursor() as cur:
cur.execute(query, (*filter_params, limit))
results = cur.fetchall()
return [[OutputData(id=str(r[0]), score=None, payload=r[2]) for r in results]]
def __del__(self) -> None:
"""
Close the database connection pool when the object is deleted.
"""
try:
# Close pool appropriately
if PSYCOPG_VERSION == 3:
self.connection_pool.close()
else:
self.connection_pool.closeall()
except Exception:
pass
def reset(self) -> None:
"""Reset the index by deleting and recreating it."""
logger.warning(f"Resetting index {self.collection_name}...")
self.delete_col()
self.create_col()