docs: explain different connection string formats in the docstring

integrations/pgvector/src/haystack_integrations/document_stores/pgvector/document_store.py

@@ -89,6 +89,7 @@ def __init__(
         hnsw_index_name: str = "haystack_hnsw_index",
         hnsw_ef_search: Optional[int] = None,
         keyword_index_name: str = "haystack_keyword_index",
+        connection_param_kwargs: Optional[Dict[str, Secret]] = None,
     ):
         """
         Creates a new PgvectorDocumentStore instance.
@@ -129,6 +130,12 @@ def __init__(
             `"hnsw"`. You can find more information about this parameter in the
             [pgvector documentation](https://github.com/pgvector/pgvector?tab=readme-ov-file#hnsw).
         :param keyword_index_name: Index name for the Keyword index.
+        :param connection_param_kwargs: A dictionary of parameters for the PostgreSQL connection.
+            If you prefer not to use the `connection_string`, you can specify connection parameters here.
+            Common parameters include 'user', 'password', 'host', 'port', & 'dbname'. For a complete list, refer to the
+            [PostgreSQL documentation](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS).
+            Use the `Secret.from_env_var()` method to securely load parameters from environment variables.
+            Note that parameters specified here take precedence over those in the `connection_string`.
         """
 
         self.connection_string = connection_string
@@ -149,6 +156,7 @@ def __init__(
         self._connection = None
         self._cursor = None
         self._dict_cursor = None
+        self.connection_param_kwargs = connection_param_kwargs or {}
 
     @property
     def cursor(self):
@@ -172,8 +180,15 @@ def connection(self):
         return self._connection
 
     def _create_connection(self):
-        conn_str = self.connection_string.resolve_value() or ""
-        connection = connect(conn_str)
+        # if connection_param_kwargs are provided use them
+        if self.connection_param_kwargs:
+            params = {key: value.resolve_value() for key, value in self.connection_param_kwargs.items()}
+            connection = connect(**params)
+        # otherwise, use the connection string
+        else:
+            conn_str = self.connection_string.resolve_value() or ""
+            connection = connect(conn_str)
+
         connection.autocommit = True
         connection.execute("CREATE EXTENSION IF NOT EXISTS vector")
         register_vector(connection)  # Note: this must be called before creating the cursors.
@@ -214,6 +229,7 @@ def to_dict(self) -> Dict[str, Any]:
             hnsw_ef_search=self.hnsw_ef_search,
             keyword_index_name=self.keyword_index_name,
             language=self.language,
+            connection_param_kwargs={key: value.to_dict() for key, value in self.connection_param_kwargs.items()},
         )
 
     @classmethod
@@ -226,6 +242,9 @@ def from_dict(cls, data: Dict[str, Any]) -> "PgvectorDocumentStore":
         :returns:
             Deserialized component.
         """
+        connection_params = data["init_parameters"]["connection_param_kwargs"]
+        deserialize_secrets_inplace(connection_params, connection_params.keys())
+
         deserialize_secrets_inplace(data["init_parameters"], ["connection_string"])
         return default_from_dict(cls, data)
 

integrations/pgvector/tests/test_document_store.py

@@ -71,6 +71,50 @@ def test_init(monkeypatch):
     assert document_store.keyword_index_name == "my_keyword_index"
 
 
+@pytest.mark.usefixtures("patches_for_unit_tests")
+def test_init_with_connection_param_kwargs(monkeypatch):
+    monkeypatch.setenv("PG_PASSWORD", "postgres_password")
+    monkeypatch.setenv("PG_USER", "postgres_user")
+    monkeypatch.setenv("PG_HOST", "postgres_host")
+    monkeypatch.setenv("PG_PORT", "postgres_port")
+
+    document_store = PgvectorDocumentStore(
+        table_name="my_table",
+        embedding_dimension=512,
+        vector_function="l2_distance",
+        recreate_table=True,
+        search_strategy="hnsw",
+        hnsw_recreate_index_if_exists=True,
+        hnsw_index_creation_kwargs={"m": 32, "ef_construction": 128},
+        hnsw_index_name="my_hnsw_index",
+        hnsw_ef_search=50,
+        keyword_index_name="my_keyword_index",
+        connection_param_kwargs={
+            "user": Secret.from_env_var("PG_USER"),
+            "host": Secret.from_env_var("PG_HOST"),
+            "password": Secret.from_env_var("PG_PASSWORD"),
+            "port": Secret.from_env_var("PG_PORT"),
+        },
+    )
+
+    assert document_store.table_name == "my_table"
+    assert document_store.embedding_dimension == 512
+    assert document_store.vector_function == "l2_distance"
+    assert document_store.recreate_table
+    assert document_store.search_strategy == "hnsw"
+    assert document_store.hnsw_recreate_index_if_exists
+    assert document_store.hnsw_index_creation_kwargs == {"m": 32, "ef_construction": 128}
+    assert document_store.hnsw_index_name == "my_hnsw_index"
+    assert document_store.hnsw_ef_search == 50
+    assert document_store.keyword_index_name == "my_keyword_index"
+    assert document_store.connection_param_kwargs == {
+        "user": Secret.from_env_var("PG_USER"),
+        "host": Secret.from_env_var("PG_HOST"),
+        "password": Secret.from_env_var("PG_PASSWORD"),
+        "port": Secret.from_env_var("PG_PORT"),
+    }
+
+
 @pytest.mark.usefixtures("patches_for_unit_tests")
 def test_to_dict(monkeypatch):
     monkeypatch.setenv("PG_CONN_STR", "some_connection_string")
@@ -103,6 +147,144 @@ def test_to_dict(monkeypatch):
             "hnsw_index_name": "my_hnsw_index",
             "hnsw_ef_search": 50,
             "keyword_index_name": "my_keyword_index",
+            "connection_param_kwargs": {},
+        },
+    }
+
+
+def test_from_dict(monkeypatch):
+    monkeypatch.setenv("PG_CONN_STR", "some_connection_string")
+
+    data = {
+        "type": "haystack_integrations.document_stores.pgvector.document_store.PgvectorDocumentStore",
+        "init_parameters": {
+            "connection_string": {"env_vars": ["PG_CONN_STR"], "strict": True, "type": "env_var"},
+            "table_name": "my_table",
+            "embedding_dimension": 512,
+            "vector_function": "l2_distance",
+            "recreate_table": True,
+            "search_strategy": "hnsw",
+            "hnsw_recreate_index_if_exists": True,
+            "language": "english",
+            "hnsw_index_creation_kwargs": {"m": 32, "ef_construction": 128},
+            "hnsw_index_name": "my_hnsw_index",
+            "hnsw_ef_search": 50,
+            "keyword_index_name": "my_keyword_index",
+            "connection_param_kwargs": {},
+        },
+    }
+
+    document_store = PgvectorDocumentStore.from_dict(data)
+
+    assert document_store.table_name == "my_table"
+    assert document_store.embedding_dimension == 512
+    assert document_store.vector_function == "l2_distance"
+    assert document_store.recreate_table
+    assert document_store.search_strategy == "hnsw"
+    assert document_store.hnsw_recreate_index_if_exists
+    assert document_store.hnsw_index_creation_kwargs == {"m": 32, "ef_construction": 128}
+    assert document_store.hnsw_index_name == "my_hnsw_index"
+    assert document_store.hnsw_ef_search == 50
+    assert document_store.keyword_index_name == "my_keyword_index"
+    assert document_store.connection_param_kwargs == {}
+
+
+def test_from_dict_with_connection_param_kwargs(monkeypatch):
+    monkeypatch.setenv("PG_PASSWORD", "postgres_password")
+    monkeypatch.setenv("PG_USER", "postgres_user")
+    monkeypatch.setenv("PG_HOST", "postgres_host")
+    monkeypatch.setenv("PG_PORT", "postgres_port")
+
+    data = {
+        "type": "haystack_integrations.document_stores.pgvector.document_store.PgvectorDocumentStore",
+        "init_parameters": {
+            "connection_string": {"env_vars": ["PG_CONN_STR"], "strict": True, "type": "env_var"},
+            "table_name": "my_table",
+            "embedding_dimension": 512,
+            "vector_function": "l2_distance",
+            "recreate_table": True,
+            "search_strategy": "hnsw",
+            "hnsw_recreate_index_if_exists": True,
+            "language": "english",
+            "hnsw_index_creation_kwargs": {"m": 32, "ef_construction": 128},
+            "hnsw_index_name": "my_hnsw_index",
+            "hnsw_ef_search": 50,
+            "keyword_index_name": "my_keyword_index",
+            "connection_param_kwargs": {
+                "user": {"env_vars": ["PG_USER"], "strict": True, "type": "env_var"},
+                "host": {"env_vars": ["PG_HOST"], "strict": True, "type": "env_var"},
+                "password": {"env_vars": ["PG_PASSWORD"], "strict": True, "type": "env_var"},
+                "port": {"env_vars": ["PG_PORT"], "strict": True, "type": "env_var"},
+            },
+        },
+    }
+
+    document_store = PgvectorDocumentStore.from_dict(data)
+
+    assert document_store.table_name == "my_table"
+    assert document_store.embedding_dimension == 512
+    assert document_store.vector_function == "l2_distance"
+    assert document_store.recreate_table
+    assert document_store.search_strategy == "hnsw"
+    assert document_store.hnsw_recreate_index_if_exists
+    assert document_store.hnsw_index_creation_kwargs == {"m": 32, "ef_construction": 128}
+    assert document_store.hnsw_index_name == "my_hnsw_index"
+    assert document_store.hnsw_ef_search == 50
+    assert document_store.keyword_index_name == "my_keyword_index"
+    assert document_store.connection_param_kwargs == {
+        "user": Secret.from_env_var("PG_USER"),
+        "host": Secret.from_env_var("PG_HOST"),
+        "password": Secret.from_env_var("PG_PASSWORD"),
+        "port": Secret.from_env_var("PG_PORT"),
+    }
+
+
+def test_to_dict_with_connection_param_kwargs(monkeypatch):
+    monkeypatch.setenv("PG_PASSWORD", "postgres_password")
+    monkeypatch.setenv("PG_USER", "postgres_user")
+    monkeypatch.setenv("PG_HOST", "postgres_host")
+    monkeypatch.setenv("PG_PORT", "postgres_port")
+
+    document_store = PgvectorDocumentStore(
+        table_name="my_table",
+        embedding_dimension=512,
+        vector_function="l2_distance",
+        recreate_table=True,
+        search_strategy="hnsw",
+        hnsw_recreate_index_if_exists=True,
+        hnsw_index_creation_kwargs={"m": 32, "ef_construction": 128},
+        hnsw_index_name="my_hnsw_index",
+        hnsw_ef_search=50,
+        keyword_index_name="my_keyword_index",
+        connection_param_kwargs={
+            "user": Secret.from_env_var("PG_USER"),
+            "host": Secret.from_env_var("PG_HOST"),
+            "password": Secret.from_env_var("PG_PASSWORD"),
+            "port": Secret.from_env_var("PG_PORT"),
+        },
+    )
+
+    assert document_store.to_dict() == {
+        "type": "haystack_integrations.document_stores.pgvector.document_store.PgvectorDocumentStore",
+        "init_parameters": {
+            "connection_string": {"env_vars": ["PG_CONN_STR"], "strict": True, "type": "env_var"},
+            "table_name": "my_table",
+            "embedding_dimension": 512,
+            "vector_function": "l2_distance",
+            "recreate_table": True,
+            "search_strategy": "hnsw",
+            "hnsw_recreate_index_if_exists": True,
+            "language": "english",
+            "hnsw_index_creation_kwargs": {"m": 32, "ef_construction": 128},
+            "hnsw_index_name": "my_hnsw_index",
+            "hnsw_ef_search": 50,
+            "keyword_index_name": "my_keyword_index",
+            "connection_param_kwargs": {
+                "user": {"env_vars": ["PG_USER"], "strict": True, "type": "env_var"},
+                "host": {"env_vars": ["PG_HOST"], "strict": True, "type": "env_var"},
+                "password": {"env_vars": ["PG_PASSWORD"], "strict": True, "type": "env_var"},
+                "port": {"env_vars": ["PG_PORT"], "strict": True, "type": "env_var"},
+            },
         },
     }
 

integrations/pgvector/tests/test_retrievers.py

@@ -61,6 +61,7 @@ def test_to_dict(self, mock_store):
                         "hnsw_index_name": "haystack_hnsw_index",
                         "hnsw_ef_search": None,
                         "keyword_index_name": "haystack_keyword_index",
+                        "connection_param_kwargs": {},
                     },
                 },
                 "filters": {"field": "value"},
@@ -91,6 +92,7 @@ def test_from_dict(self, monkeypatch):
                         "hnsw_index_name": "haystack_hnsw_index",
                         "hnsw_ef_search": None,
                         "keyword_index_name": "haystack_keyword_index",
+                        "connection_param_kwargs": {},
                     },
                 },
                 "filters": {"field": "value"},
@@ -186,6 +188,7 @@ def test_to_dict(self, mock_store):
                         "hnsw_index_name": "haystack_hnsw_index",
                         "hnsw_ef_search": None,
                         "keyword_index_name": "haystack_keyword_index",
+                        "connection_param_kwargs": {},
                     },
                 },
                 "filters": {"field": "value"},
@@ -215,6 +218,7 @@ def test_from_dict(self, monkeypatch):
                         "hnsw_index_name": "haystack_hnsw_index",
                         "hnsw_ef_search": None,
                         "keyword_index_name": "haystack_keyword_index",
+                        "connection_param_kwargs": {},
                     },
                 },
                 "filters": {"field": "value"},
@@ -263,6 +267,7 @@ def test_from_dict_without_filter_policy(self, monkeypatch):
                         "hnsw_index_name": "haystack_hnsw_index",
                         "hnsw_ef_search": None,
                         "keyword_index_name": "haystack_keyword_index",
+                        "connection_param_kwargs": {},
                     },
                 },
                 "filters": {"field": "value"},