Use a server-side cursor

arkindex/documents/export/__init__.py

@@ -34,10 +34,11 @@ EXPORT_QUERIES = [
 
 def run_pg_query(query):
     """
-    Run a single Postgresql query and split the results
-    into chunks
+    Run a single Postgresql query and split the results into chunks.
+    When a name is given to a cursor, psycopg2 uses a server-side cursor; we just use a random string as a name.
     """
-    with connections['default'].cursor() as pg_cursor:
+    with connections['default'].create_cursor(name=str(uuid.uuid4())) as pg_cursor:
+        pg_cursor.itersize = BATCH_SIZE
         pg_cursor.execute(query)
 
         while True: