What happens if I save the same artifacts & records twice?¶

LaminDB’s operations are idempotent in the sense defined in this document.

This allows you to re-run a notebook or script without erroring or duplicating data. Similar behavior holds for human data entry.

Summary¶

Metadata records¶

If you try to create any metadata record (Registry) and upon_create_search_names is True (the default):

LaminDB will warn you if a record with similar name exists and display a table of similar existing records.
You can then decide whether you’d like to save a record to the database or rather query an existing one from the table.
If a name already has an exact match in a registry, LaminDB will return it instead of creating a new record. For versioned entities, also the version must be passed.

If you set upon_create_search_names to False, you’ll directly populate the DB.

Data: artifacts & collections¶

If you try to create a Artifact object from the same content, depending on upon_artifact_create_if_hash_exists,

you’ll get an existing object, if upon_artifact_create_if_hash_exists = "warn_return_existing" (the default)
you’ll get an error, if upon_artifact_create_if_hash_exists = "error"
you’ll get a warning and a new object, if upon_artifact_create_if_hash_exists = "warn_create_new"

Examples¶

!lamin init --storage ./test-idempotency

💡 connected lamindb: testuser1/test-idempotency

import lamindb as ln
import pytest

ln.settings.verbosity = "hint"
ln.settings.transform.stem_uid = "ANW20Fr4eZgM"
ln.settings.transform.version = "1"
ln.track()

💡 connected lamindb: testuser1/test-idempotency

💡 notebook imports: lamindb==0.72.0 pytest==8.2.1

💡 saved: Transform(version='1', uid='ANW20Fr4eZgM5zKv', name='What happens if I save the same artifacts & records twice?', key='idempotency', type='notebook', updated_at=2024-05-20 08:58:18 UTC, created_by_id=1)

💡 saved: Run(uid='R40i0MvUdj5wL3llcdCL', transform_id=1, created_by_id=1)

💡 tracked pip freeze > /home/runner/.cache/lamindb/run_env_pip_R40i0MvUdj5wL3llcdCL.txt

Metadata records¶

assert ln.settings.upon_create_search_names

Let us add a first record to the ULabel registry:

label = ln.ULabel(name="My project 1")
label.save()

ULabel(updated_at=2024-05-20 08:58:20 UTC, uid='e3YaAmJN', name='My project 1', created_by_id=1)

If we create a new record, we’ll automatically get search results that give clues on whether we are prone to duplicating an entry:

label = ln.ULabel(name="My project 1a")

label.save()

ULabel(updated_at=2024-05-20 08:58:20 UTC, uid='afo2kuMG', name='My project 1a', created_by_id=1)

In case we match an existing name directly, we’ll get the existing object:

label = ln.ULabel(name="My project 1")

❗ loaded ULabel record with same name: 'My project 1' (disable via `ln.settings.upon_create_search_names`)

If we save it again, it will not create a new entry in the registry:

label.save()

ULabel(updated_at=2024-05-20 08:58:20 UTC, uid='e3YaAmJN', name='My project 1', created_by_id=1)

Now, if we create a third record, we’ll get two alternatives:

label = ln.ULabel(name="My project 1b")

If we prefer to not perform a search, e.g. for performance reasons or too noisy logging, we can switch it off.

ln.settings.upon_create_search_names = False

label = ln.ULabel(name="My project 1c")

In this walkthrough, switch it back on:

ln.settings.upon_create_search_names = True

Data: artifacts and collections¶

Warn upon trying to re-ingest an existing artifact¶

assert ln.settings.upon_artifact_create_if_hash_exists == "warn_return_existing"

filepath = ln.core.datasets.file_fcs()

Create an Artifact:

artifact = ln.Artifact(filepath, description="My fcs artifact")
artifact.save()

💡 path content will be copied to default storage upon `save()` with key `None` ('.lamindb/geRYWso4sA2pi9jHSsch.fcs')

✅ storing artifact 'geRYWso4sA2pi9jHSsch' at '/home/runner/work/lamindb/lamindb/docs/faq/test-idempotency/.lamindb/geRYWso4sA2pi9jHSsch.fcs'

Artifact(updated_at=2024-05-20 08:58:21 UTC, uid='geRYWso4sA2pi9jHSsch', suffix='.fcs', description='My fcs artifact', size=6785467, hash='KCEXRahJ-Ui9Y6nksQ8z1A', hash_type='md5', visibility=1, key_is_virtual=True, created_by_id=1, storage_id=1, transform_id=1, run_id=1)

Create an Artifact from the same path:

artifact2 = ln.Artifact(filepath, description="My fcs artifact")

❗ returning existing artifact with same hash: Artifact(updated_at=2024-05-20 08:58:21 UTC, uid='geRYWso4sA2pi9jHSsch', suffix='.fcs', description='My fcs artifact', size=6785467, hash='KCEXRahJ-Ui9Y6nksQ8z1A', hash_type='md5', visibility=1, key_is_virtual=True, created_by_id=1, storage_id=1, transform_id=1, run_id=1)

It gives us the existing object:

assert artifact.id == artifact2.id
assert artifact.run == artifact2.run

If you save it again, nothing will happen (the operation is idempotent):

artifact2.save()

Artifact(updated_at=2024-05-20 08:58:21 UTC, uid='geRYWso4sA2pi9jHSsch', suffix='.fcs', description='My fcs artifact', size=6785467, hash='KCEXRahJ-Ui9Y6nksQ8z1A', hash_type='md5', visibility=1, key_is_virtual=True, created_by_id=1, storage_id=1, transform_id=1, run_id=1)

In the hidden cell below, you’ll see how this interplays with data lineage.

Error upon trying to re-ingest an existing artifact¶

ln.settings.upon_artifact_create_if_hash_exists = "error"

In this case, you’ll not be able to create an object from the same content:

with pytest.raises(FileExistsError):
    artifact3 = ln.Artifact(filepath, description="My new fcs artifact")

Warn and create a new artifact¶

Lastly, let us discuss the following setting:

ln.settings.upon_artifact_create_if_hash_exists = "warn_create_new"

In this case, you’ll create a new object:

artifact4 = ln.Artifact(filepath, description="My new fcs artifact")
artifact4.save()

❗ creating new Artifact object despite existing artifact with same hash: Artifact(updated_at=2024-05-20 08:58:21 UTC, uid='geRYWso4sA2pi9jHSsch', suffix='.fcs', description='My fcs artifact', size=6785467, hash='KCEXRahJ-Ui9Y6nksQ8z1A', hash_type='md5', visibility=1, key_is_virtual=True, created_by_id=1, storage_id=1, transform_id=1, run_id=1)

💡 path content will be copied to default storage upon `save()` with key `None` ('.lamindb/eoZtbsAnPY0I8lvC3AOh.fcs')

✅ storing artifact 'eoZtbsAnPY0I8lvC3AOh' at '/home/runner/work/lamindb/lamindb/docs/faq/test-idempotency/.lamindb/eoZtbsAnPY0I8lvC3AOh.fcs'

Artifact(updated_at=2024-05-20 08:58:22 UTC, uid='eoZtbsAnPY0I8lvC3AOh', suffix='.fcs', description='My new fcs artifact', size=6785467, hash='KCEXRahJ-Ui9Y6nksQ8z1A', hash_type='md5', visibility=1, key_is_virtual=True, created_by_id=1, storage_id=1, transform_id=1, run_id=2)

You can verify that it’s a new entry by comparing the ids:

assert artifact4.id != artifact.id

artifact4.filter(hash="KCEXRahJ-Ui9Y6nksQ8z1A").df()

	version	created_at	created_by_id	updated_at	uid	storage_id	key	suffix	accessor	description	size	hash	hash_type	n_objects	n_observations	transform_id	run_id	visibility	key_is_virtual
id
1	None	2024-05-20 08:58:21.734588+00:00	1	2024-05-20 08:58:21.794564+00:00	geRYWso4sA2pi9jHSsch	1	None	.fcs	None	My fcs artifact	6785467	KCEXRahJ-Ui9Y6nksQ8z1A	md5	None	None	1	1	1	True
2	None	2024-05-20 08:58:22.806007+00:00	1	2024-05-20 08:58:22.806060+00:00	eoZtbsAnPY0I8lvC3AOh	1	None	.fcs	None	My new fcs artifact	6785467	KCEXRahJ-Ui9Y6nksQ8z1A	md5	None	None	1	2	1	True

!lamin delete --force test-idempotency
!rm -r test-idempotency

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.11.9/x64/bin/lamin", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/rich_click/rich_command.py", line 367, in __call__
    return super().__call__(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/rich_click/rich_command.py", line 152, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/lamin_cli/__main__.py", line 103, in delete
    return delete(instance, force=force)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/lamindb_setup/_delete.py", line 98, in delete
    n_objects = check_storage_is_empty(
                ^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/hostedtoolcache/Python/3.11.9/x64/lib/python3.11/site-packages/lamindb_setup/core/upath.py", line 760, in check_storage_is_empty
    raise InstanceNotEmpty(message)
lamindb_setup.core.upath.InstanceNotEmpty: Storage /home/runner/work/lamindb/lamindb/docs/faq/test-idempotency/.lamindb contains 2 objects ('_is_initialized' ignored) - delete them prior to deleting the instance
['/home/runner/work/lamindb/lamindb/docs/faq/test-idempotency/.lamindb/_is_initialized', '/home/runner/work/lamindb/lamindb/docs/faq/test-idempotency/.lamindb/eoZtbsAnPY0I8lvC3AOh.fcs', '/home/runner/work/lamindb/lamindb/docs/faq/test-idempotency/.lamindb/geRYWso4sA2pi9jHSsch.fcs']