python: Use direct TLS connections for SQLAlchemy

python/sqlalchemy/README.md

@@ -33,6 +33,19 @@ The code automatically detects the user type and adjusts its behavior accordingl
 * This code is not tested in every AWS Region. For more information, see
   [AWS Regional Services](https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services).
 
+## TLS connection configuration
+
+This example uses direct TLS connections where supported, and verifies the server certificate is trusted. Verified SSL
+connections should be used where possible to ensure data security during transmission.
+
+* Driver versions following the release of PostgreSQL 17 support direct TLS connections, bypassing the traditional
+  PostgreSQL connection preamble
+* Direct TLS connections provide improved connection performance and enhanced security
+* Not all PostgreSQL drivers support direct TLS connections yet, or only in recent versions following PostgreSQL 17
+* Ensure your installed driver version supports direct TLS negotiation, or use a version that is at least as recent as
+  the one used in this sample
+* If your driver doesn't support direct TLS connections, you may need to use the traditional preamble connection instead
+
 ## Run the example
 
 ### Prerequisites

python/sqlalchemy/src/example.py

@@ -1,5 +1,6 @@
 ## Dependencies for engine creation
 import os
+import psycopg2.extensions
 from sqlalchemy import create_engine, select, event
 from sqlalchemy.engine import URL
 
@@ -42,13 +43,19 @@ def create_dsql_engine():
         host=cluster_endpoint, 
         database="postgres"
     )
-
+
+    connect_args = {
+        "sslmode": "verify-full",
+        "sslrootcert": "./root.pem",
+    }
+
+    # Use the more efficient connection method if it's supported.
+    if psycopg2.extensions.libpq_version() >= 170000:
+        connect_args["sslnegotiation"] = "direct"
+
     # Create the engine
-    engine = create_engine(
-        url, 
-        connect_args={"sslmode": "verify-full", "sslrootcert": "./root.pem"},
-    )
-
+    engine = create_engine(url, connect_args=connect_args)
+
     # Adds a listener that creates a new token every time a new connection is created in the SQLAlchemy engine
     @event.listens_for(engine, "do_connect")
     def add_token_to_params(dialect, conn_rec, cargs, cparams):