clarify shallow copy

diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index cc963a6fd32189bd410226f250a5a3f64f1dc1a9..2ec820c739757f34a740fe4fc56832bbd087f824 100644 (file)
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -233,7 +233,7 @@ class PGArray(sqltypes.MutableType, sqltypes.Concatenable, sqltypes.TypeEngine):
                           multi-dimensional arrays like `INTEGER[][]`, are constructed as `PGArray(Integer)`, not as
                           `PGArray(PGArray(Integer))` or such. The type mapping figures out on the fly
         :param mutable:   Defaults to True: specify whether lists passed to this class should be considered mutable.
-                          If so, then they are shallow-copied.
+                          If so, generic copy operations (typically used by the ORM) will shallow-copy values.
         """
         if isinstance(item_type, type):
             item_type = item_type()