perf tweaks

- avoid abc checks in distill_20
- ColumnEntity subclasses are unique to their compile state and
have no querycontext specific state.  They can do a simple memoize of their
fetch_column without using attributes, and they can memoize their
_getter() too so that it goes into the cache, just like
instance_processor() does.
- unify ORMColumnEntity and RawColumnEntity for the row processor part,
add some test coverage for the case where it is used in a from_statement
- do a faster generate if there are no memoized entries
- query._params is always immutabledict
Change-Id: I1e2dfe607a1749b5b434fc11f9348ee631501dfa

3 files changed, 48 insertions, 3 deletions

diff --git a/test/orm/test_froms.py b/test/orm/test_froms.py
index 1fde343d8..62227ece2 100644
--- a/test/orm/test_froms.py
+++ b/test/orm/test_froms.py
@@ -2310,6 +2310,18 @@ class MixedEntitiesTest(QueryTest, AssertsCompiledSQL):
         )
         assert result == expected
 
+    def test_multi_columns_3(self):
+        User = self.classes.User
+        users = self.tables.users
+
+        sess = create_session()
+
+        q = sess.query(User.id, User.name)
+        stmt = select([users]).order_by(users.c.id)
+        q = q.from_statement(stmt)
+
+        eq_(q.all(), [(7, "jack"), (8, "ed"), (9, "fred"), (10, "chuck")])
+
     def test_raw_columns(self):
         addresses, users, User = (
             self.tables.addresses,
diff --git a/test/orm/test_lazy_relations.py b/test/orm/test_lazy_relations.py
index 65158dbd4..c30086bea 100644
--- a/test/orm/test_lazy_relations.py
+++ b/test/orm/test_lazy_relations.py
@@ -439,9 +439,7 @@ class LazyTest(_fixtures.FixtureTest):
             def process_query_conditionally(self, query):
                 """process query during a lazyload"""
                 canary()
-                params = dict(query.load_options._params)
-                query.load_options += {"_params": params}
-                query.load_options._params.update(dict(name=self.crit))
+                query.params.non_generative(query, dict(name=self.crit))
 
         s = Session()
         ed = s.query(User).options(MyOption("ed")).filter_by(name="ed").one()
diff --git a/test/orm/test_query.py b/test/orm/test_query.py
index a7cc82ddf..c2f0c4424 100644
--- a/test/orm/test_query.py
+++ b/test/orm/test_query.py
@@ -4440,6 +4440,26 @@ class TextTest(QueryTest, AssertsCompiledSQL):
 
         self.assert_sql_count(testing.db, go, 1)
 
+    def test_textual_select_orm_columns(self):
+        # test that columns using column._label match, as well as that
+        # ordering doesn't matter.
+        User = self.classes.User
+        Address = self.classes.Address
+        users = self.tables.users
+        addresses = self.tables.addresses
+
+        s = create_session()
+        q = s.query(User.name, User.id, Address.id).from_statement(
+            text(
+                "select users.name AS users_name, users.id AS users_id, "
+                "addresses.id AS addresses_id FROM users JOIN addresses "
+                "ON users.id = addresses.user_id WHERE users.id=8 "
+                "ORDER BY addresses.id"
+            ).columns(users.c.name, users.c.id, addresses.c.id)
+        )
+
+        eq_(q.all(), [("ed", 8, 2), ("ed", 8, 3), ("ed", 8, 4)])
+
     @testing.combinations(
         (
             False,
@@ -4564,6 +4584,21 @@ class TextTest(QueryTest, AssertsCompiledSQL):
             [User(id=7), User(id=8), User(id=9), User(id=10)],
         )
 
+    def test_columns_via_textasfrom_from_statement(self):
+        User = self.classes.User
+        s = create_session()
+
+        eq_(
+            s.query(User.id, User.name)
+            .from_statement(
+                text("select * from users order by id").columns(
+                    id=Integer, name=String
+                )
+            )
+            .all(),
+            [(7, "jack"), (8, "ed"), (9, "fred"), (10, "chuck")],
+        )
+
     def test_via_textasfrom_use_mapped_columns(self):
         User = self.classes.User
         s = create_session()