gistfile1.txt

from sqlalchemy import create_engine, Column, Integer
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

Base = declarative_base()

engine = create_engine('postgresql+psycopg2://testman:testmanpass@localhost:5432/testman')

class TestMan(Base):
    __tablename__ = "testman"
    id = Column(Integer, primary_key=True)
    value = Column(Integer)

Base.metadata.create_all(engine)

Session = sessionmaker(bind=engine)
session1 = Session()
session2 = Session()
for i in xrange(10000):
    session1.add(TestMan(value=i))
session1.commit()

results = session1.query(TestMan).execution_options(stream_results=True).filter(TestMan.value >= 0).yield_per(20)
for count, r in enumerate(results):
    if count % 100 == 0:
        print "%s" % count
        session2.query(TestMan).filter(TestMan.value <= count).delete()
        session2.commit()


print "Got here!"
session2.close()
print "SECOND GOT HERE"