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"""This series of tests illustrates different ways to INSERT a large number
of rows in bulk.
"""
from . import Profiler
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, create_engine, bindparam
from sqlalchemy.orm import Session
Base = declarative_base()
engine = None
class Customer(Base):
__tablename__ = "customer"
id = Column(Integer, primary_key=True)
name = Column(String(255))
description = Column(String(255))
Profiler.init("bulk_inserts", num=100000)
@Profiler.setup
def setup_database(dburl, echo, num):
global engine
engine = create_engine(dburl, echo=echo)
Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
@Profiler.profile
def test_flush_no_pk(n):
"""Individual INSERT statements via the ORM, calling upon last row id"""
session = Session(bind=engine)
for chunk in range(0, n, 1000):
session.add_all([
Customer(
name='customer name %d' % i,
description='customer description %d' % i)
for i in range(chunk, chunk + 1000)
])
session.flush()
session.commit()
@Profiler.profile
def test_bulk_save_return_pks(n):
"""Individual INSERT statements in "bulk", but calling upon last row id"""
session = Session(bind=engine)
session.bulk_save_objects([
Customer(
name='customer name %d' % i,
description='customer description %d' % i
)
for i in range(n)
], return_defaults=True)
session.commit()
@Profiler.profile
def test_flush_pk_given(n):
"""Batched INSERT statements via the ORM, PKs already defined"""
session = Session(bind=engine)
for chunk in range(0, n, 1000):
session.add_all([
Customer(
id=i + 1,
name='customer name %d' % i,
description='customer description %d' % i)
for i in range(chunk, chunk + 1000)
])
session.flush()
session.commit()
@Profiler.profile
def test_bulk_save(n):
"""Batched INSERT statements via the ORM in "bulk", discarding PKs."""
session = Session(bind=engine)
session.bulk_save_objects([
Customer(
name='customer name %d' % i,
description='customer description %d' % i
)
for i in range(n)
])
session.commit()
@Profiler.profile
def test_bulk_insert_mappings(n):
"""Batched INSERT statements via the ORM "bulk", using dictionaries."""
session = Session(bind=engine)
session.bulk_insert_mappings(Customer, [
dict(
name='customer name %d' % i,
description='customer description %d' % i
)
for i in range(n)
])
session.commit()
@Profiler.profile
def test_core_insert(n):
"""A single Core INSERT construct inserting mappings in bulk."""
conn = engine.connect()
conn.execute(
Customer.__table__.insert(),
[
dict(
name='customer name %d' % i,
description='customer description %d' % i
)
for i in range(n)
])
@Profiler.profile
def test_dbapi_raw(n):
"""The DBAPI's API inserting rows in bulk."""
conn = engine.pool._creator()
cursor = conn.cursor()
compiled = Customer.__table__.insert().values(
name=bindparam('name'),
description=bindparam('description')).\
compile(dialect=engine.dialect)
if compiled.positional:
args = (
('customer name %d' % i, 'customer description %d' % i)
for i in range(n))
else:
args = (
dict(
name='customer name %d' % i,
description='customer description %d' % i
)
for i in range(n)
)
cursor.executemany(
str(compiled),
list(args)
)
conn.commit()
conn.close()
if __name__ == '__main__':
Profiler.main()
|
