"""This series of tests illustrates different ways to INSERT a large number
of rows in bulk.
"""
from sqlalchemy import bindparam
from sqlalchemy import Column
from sqlalchemy import create_engine
from sqlalchemy import Integer
from sqlalchemy import String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session
from . import Profiler
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()