- starting to groom the branch for its inclusion

- one-to-many relationships now maintain a list of positive
parent-child associations within the flush, preventing
previous parents marked as deleted from cascading a
delete or NULL foreign key set on those child objects,
despite the end-user not removing the child from the old
association. [ticket:1764]
- re-established Preprocess as unique on their arguments,
as they were definitely duped in inheritance scenarios
- added a "memo" feature to UOWTransaction which represents the usual
pattern of using the .attributes collection
- added the test case from [ticket:1081] into perf/

1 files changed, 84 insertions, 0 deletions

diff --git a/test/perf/large_flush.py b/test/perf/large_flush.py
new file mode 100644
index 000000000..431a28944
--- /dev/null
+++ b/test/perf/large_flush.py
@@ -0,0 +1,84 @@
+import sqlalchemy as sa
+from sqlalchemy import create_engine, MetaData, orm
+from sqlalchemy import Column, ForeignKey
+from sqlalchemy import Integer, String
+from sqlalchemy.orm import mapper
+from sqlalchemy.test import profiling
+
+class Object(object):
+    pass
+
+class Q(Object):
+    pass
+
+class A(Object):
+    pass
+
+class C(Object):
+    pass
+
+class WC(C):
+    pass
+
+engine = create_engine('sqlite:///:memory:', echo=True)
+
+sm = orm.sessionmaker(bind=engine)
+
+SA_Session = orm.scoped_session(sm)
+
+SA_Metadata = MetaData()
+
+object_table =  sa.Table('Object',
+                          SA_Metadata,
+                          Column('ObjectID', Integer,primary_key=True),
+                          Column('Type', String(1), nullable=False))
+
+q_table = sa.Table('Q',
+                   SA_Metadata,
+                   Column('QID', Integer, ForeignKey('Object.ObjectID'),primary_key=True))
+
+c_table = sa.Table('C',
+                   SA_Metadata,
+                   Column('CID', Integer, ForeignKey('Object.ObjectID'),primary_key=True))
+
+wc_table = sa.Table('WC',
+                    SA_Metadata,
+                    Column('WCID', Integer, ForeignKey('C.CID'), primary_key=True))
+
+a_table = sa.Table('A',
+                   SA_Metadata,
+                   Column('AID', Integer, ForeignKey('Object.ObjectID'),primary_key=True),
+                   Column('QID', Integer, ForeignKey('Q.QID')),
+                   Column('CID', Integer, ForeignKey('C.CID')))
+
+mapper(Object, object_table, polymorphic_on=object_table.c.Type, polymorphic_identity='O')
+
+mapper(Q, q_table, inherits=Object, polymorphic_identity='Q')
+mapper(C, c_table, inherits=Object, polymorphic_identity='C')
+mapper(WC, wc_table, inherits=C, polymorphic_identity='W')
+
+mapper(A, a_table, inherits=Object, polymorphic_identity='A',
+       properties = {
+                     'Q' : orm.relation(Q,primaryjoin=a_table.c.QID==q_table.c.QID,
+                                        backref='As'
+                                        ),
+                     'C' : orm.relation(C,primaryjoin=a_table.c.CID==c_table.c.CID,
+                                        backref='A',
+                                        uselist=False)
+                     }
+       )
+
+SA_Metadata.create_all(engine)
+
+@profiling.profiled('large_flush', always=True, sort=['file'])
+def generate_error():
+    q = Q()
+    for j in range(100): #at 306 the error does not pop out (depending on recursion depth)
+        a = A()
+        a.Q = q
+        a.C = WC()
+
+    SA_Session.add(q)
+    SA_Session.commit() #here the error pops out
+
+generate_error()
\ No newline at end of file