- Session.merge() is performance optimized, using half the

call counts for "load=False" mode compared to 0.5 and
significantly fewer SQL queries in the case of collections
for "load=True" mode.

1 files changed, 85 insertions, 0 deletions

diff --git a/test/aaa_profiling/test_orm.py b/test/aaa_profiling/test_orm.py
new file mode 100644
index 000000000..d88e73c67
--- /dev/null
+++ b/test/aaa_profiling/test_orm.py
@@ -0,0 +1,85 @@
+from sqlalchemy.test.testing import eq_, assert_raises, assert_raises_message
+from sqlalchemy import exc as sa_exc, util, Integer, String, ForeignKey
+from sqlalchemy.orm import exc as orm_exc, mapper, relation, sessionmaker
+
+from sqlalchemy.test import testing, profiling
+from test.orm import _base
+from sqlalchemy.test.schema import Table, Column
+
+
+class MergeTest(_base.MappedTest):
+    @classmethod
+    def define_tables(cls, metadata):
+        parent = Table('parent', metadata,
+            Column('id', Integer, primary_key=True, test_needs_autoincrement=True),
+            Column('data', String(20))
+        )
+
+        child = Table('child', metadata,
+            Column('id', Integer, primary_key=True, test_needs_autoincrement=True),
+            Column('data', String(20)),
+            Column('parent_id', Integer, ForeignKey('parent.id'), nullable=False)
+        )
+
+
+    @classmethod
+    def setup_classes(cls):
+        class Parent(_base.BasicEntity):
+            pass
+        class Child(_base.BasicEntity):
+            pass
+
+    @classmethod
+    @testing.resolve_artifact_names
+    def setup_mappers(cls):
+        mapper(Parent, parent, properties={
+            'children':relation(Child, backref='parent')
+        })
+        mapper(Child, child)
+
+    @classmethod
+    @testing.resolve_artifact_names
+    def insert_data(cls):
+        parent.insert().execute(
+            {'id':1, 'data':'p1'},
+        )
+        child.insert().execute(
+            {'id':1, 'data':'p1c1', 'parent_id':1},
+        )
+    
+    @testing.resolve_artifact_names
+    def test_merge_no_load(self):
+        sess = sessionmaker()()
+        sess2 = sessionmaker()()
+        
+        p1 = sess.query(Parent).get(1)
+        p1.children
+        
+        # down from 185 on this
+        # this is a small slice of a usually bigger
+        # operation so using a small variance
+        @profiling.function_call_count(106, variance=0.001)
+        def go():
+            p2 = sess2.merge(p1, load=False)
+            
+        go()
+
+    @testing.resolve_artifact_names
+    def test_merge_load(self):
+        sess = sessionmaker()()
+        sess2 = sessionmaker()()
+
+        p1 = sess.query(Parent).get(1)
+        p1.children
+
+        # preloading of collection took this down from 1728
+        # to 1192 using sqlite3
+        @profiling.function_call_count(1192)
+        def go():
+            p2 = sess2.merge(p1)
+        go()
+        
+        # one more time, count the SQL
+        sess2 = sessionmaker()()
+        self.assert_sql_count(testing.db, go, 2)
+