+def _setup_postgresql_features(conn):
+ """ Set up a dictionary with various optional Postgresql/Postgis features that
+ depend on the database version.
+ """
+ pg_version = conn.server_version_tuple()
+ return {
+ 'has_index_non_key_column' : pg_version >= (11, 0, 0)
+ }
+
+class SQLPreprocessor: