feat(python): add read_consistency_interval argument (#828)

This PR refactors how we handle read consistency: does the `LanceTable`
class always pick up modifications to the table made by other instance
or processes. Users have three options they can set at the connection
level:

1. (Default) `read_consistency_interval=None` means it will not check at
all. Users can call `table.checkout_latest()` to manually check for
updates.
2. `read_consistency_interval=timedelta(0)` means **always** check for
updates, giving strong read consistency.
3. `read_consistency_interval=timedelta(seconds=20)` means check for
updates every 20 seconds. This is eventual consistency, a compromise
between the two options above.

## Table reference state

There is now an explicit difference between a `LanceTable` that tracks
the current version and one that is fixed at a historical version. We
now enforce that users cannot write if they have checked out an old
version. They are instructed to call `checkout_latest()` before calling
the write methods.

Since `conn.open_table()` doesn't have a parameter for version, users
will only get fixed references if they call `table.checkout()`.

The difference between these two can be seen in the repr: Table that are
fixed at a particular version will have a `version` displayed in the
repr. Otherwise, the version will not be shown.

```python
>>> table
LanceTable(connection=..., name="my_table")
>>> table.checkout(1)
>>> table
LanceTable(connection=..., name="my_table", version=1)
```

I decided to not create different classes for these states, because I
think we already have enough complexity with the Cloud vs OSS table
references.

Based on #812

python/README.md

@@ -42,6 +42,12 @@ To run the unit tests:
 pytest
 ```
 
+To run the doc tests:
+
+```bash
+pytest --doctest-modules lancedb
+```
+
 To run linter and automatically fix all errors:
 
 ```bash

python/lancedb/__init__.py

@@ -13,6 +13,7 @@
 
 import importlib.metadata
 import os
+from datetime import timedelta
 from typing import Optional
 
 __version__ = importlib.metadata.version("lancedb")
@@ -30,6 +31,7 @@ def connect(
     api_key: Optional[str] = None,
     region: str = "us-east-1",
     host_override: Optional[str] = None,
+    read_consistency_interval: Optional[timedelta] = None,
 ) -> DBConnection:
     """Connect to a LanceDB database.
 
@@ -45,6 +47,18 @@ def connect(
         The region to use for LanceDB Cloud.
     host_override: str, optional
         The override url for LanceDB Cloud.
+    read_consistency_interval: timedelta, default None
+        (For LanceDB OSS only)
+        The interval at which to check for updates to the table from other
+        processes. If None, then consistency is not checked. For performance
+        reasons, this is the default. For strong consistency, set this to
+        zero seconds. Then every read will check for updates from other
+        processes. As a compromise, you can set this to a non-zero timedelta
+        for eventual consistency. If more than that interval has passed since
+        the last check, then the table will be checked for updates. Note: this
+        consistency only applies to read operations. Write operations are
+        always consistent.
+
 
     Examples
     --------
@@ -73,4 +87,4 @@ def connect(
         if api_key is None:
             raise ValueError(f"api_key is required to connected LanceDB cloud: {uri}")
         return RemoteDBConnection(uri, api_key, region, host_override)
-    return LanceDBConnection(uri)
+    return LanceDBConnection(uri, read_consistency_interval=read_consistency_interval)

python/lancedb/db.py

@@ -26,6 +26,8 @@ from .table import LanceTable, Table
 from .util import fs_from_uri, get_uri_location, get_uri_scheme, join_uri
 
 if TYPE_CHECKING:
+    from datetime import timedelta
+
     from .common import DATA, URI
     from .embeddings import EmbeddingFunctionConfig
     from .pydantic import LanceModel
@@ -118,7 +120,7 @@ class DBConnection(EnforceOverrides):
         >>> data = [{"vector": [1.1, 1.2], "lat": 45.5, "long": -122.7},
         ...         {"vector": [0.2, 1.8], "lat": 40.1, "long":  -74.1}]
         >>> db.create_table("my_table", data)
-        LanceTable(my_table)
+        LanceTable(connection=..., name="my_table")
         >>> db["my_table"].head()
         pyarrow.Table
         vector: fixed_size_list<item: float>[2]
@@ -139,7 +141,7 @@ class DBConnection(EnforceOverrides):
         ...    "long": [-122.7, -74.1]
         ... })
         >>> db.create_table("table2", data)
-        LanceTable(table2)
+        LanceTable(connection=..., name="table2")
         >>> db["table2"].head()
         pyarrow.Table
         vector: fixed_size_list<item: float>[2]
@@ -161,7 +163,7 @@ class DBConnection(EnforceOverrides):
         ...   pa.field("long", pa.float32())
         ... ])
         >>> db.create_table("table3", data, schema = custom_schema)
-        LanceTable(table3)
+        LanceTable(connection=..., name="table3")
         >>> db["table3"].head()
         pyarrow.Table
         vector: fixed_size_list<item: float>[2]
@@ -195,7 +197,7 @@ class DBConnection(EnforceOverrides):
         ...     pa.field("price", pa.float32()),
         ... ])
         >>> db.create_table("table4", make_batches(), schema=schema)
-        LanceTable(table4)
+        LanceTable(connection=..., name="table4")
 
         """
         raise NotImplementedError
@@ -243,6 +245,16 @@ class LanceDBConnection(DBConnection):
     ----------
     uri: str or Path
         The root uri of the database.
+    read_consistency_interval: timedelta, default None
+        The interval at which to check for updates to the table from other
+        processes. If None, then consistency is not checked. For performance
+        reasons, this is the default. For strong consistency, set this to
+        zero seconds. Then every read will check for updates from other
+        processes. As a compromise, you can set this to a non-zero timedelta
+        for eventual consistency. If more than that interval has passed since
+        the last check, then the table will be checked for updates. Note: this
+        consistency only applies to read operations. Write operations are
+        always consistent.
 
     Examples
     --------
@@ -250,22 +262,24 @@ class LanceDBConnection(DBConnection):
     >>> db = lancedb.connect("./.lancedb")
     >>> db.create_table("my_table", data=[{"vector": [1.1, 1.2], "b": 2},
     ...                                   {"vector": [0.5, 1.3], "b": 4}])
-    LanceTable(my_table)
+    LanceTable(connection=..., name="my_table")
     >>> db.create_table("another_table", data=[{"vector": [0.4, 0.4], "b": 6}])
-    LanceTable(another_table)
+    LanceTable(connection=..., name="another_table")
     >>> sorted(db.table_names())
     ['another_table', 'my_table']
     >>> len(db)
     2
     >>> db["my_table"]
-    LanceTable(my_table)
+    LanceTable(connection=..., name="my_table")
     >>> "my_table" in db
     True
     >>> db.drop_table("my_table")
     >>> db.drop_table("another_table")
     """
 
-    def __init__(self, uri: URI):
+    def __init__(
+        self, uri: URI, *, read_consistency_interval: Optional[timedelta] = None
+    ):
         if not isinstance(uri, Path):
             scheme = get_uri_scheme(uri)
         is_local = isinstance(uri, Path) or scheme == "file"
@@ -277,6 +291,14 @@ class LanceDBConnection(DBConnection):
         self._uri = str(uri)
 
         self._entered = False
+        self.read_consistency_interval = read_consistency_interval
+
+    def __repr__(self) -> str:
+        val = f"{self.__class__.__name__}({self._uri}"
+        if self.read_consistency_interval is not None:
+            val += f", read_consistency_interval={repr(self.read_consistency_interval)}"
+        val += ")"
+        return val
 
     @property
     def uri(self) -> str:

python/lancedb/pydantic.py

@@ -304,7 +304,7 @@ class LanceModel(pydantic.BaseModel):
     ...     name: str
     ...     vector: Vector(2)
     ...
-    >>> db = lancedb.connect("/tmp")
+    >>> db = lancedb.connect("./example")
     >>> table = db.create_table("test", schema=TestModel.to_arrow_schema())
     >>> table.add([
     ...     TestModel(name="test", vector=[1.0, 2.0])

python/lancedb/table.py

@@ -14,7 +14,10 @@
 from __future__ import annotations
 
 import inspect
+import time
 from abc import ABC, abstractmethod
+from dataclasses import dataclass
+from datetime import timedelta
 from functools import cached_property
 from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Tuple, Union
 
@@ -41,8 +44,6 @@ from .util import (
 from .utils.events import register_event
 
 if TYPE_CHECKING:
-    from datetime import timedelta
-
     import PIL
     from lance.dataset import CleanupStats, ReaderLike
 
@@ -299,7 +300,7 @@ class Table(ABC):
 
             import lance
 
-            dataset = lance.dataset("/tmp/images.lance")
+            dataset = lance.dataset("./images.lance")
             dataset.create_scalar_index("category")
         """
         raise NotImplementedError
@@ -642,23 +643,145 @@ class Table(ABC):
         """
 
 
+class _LanceDatasetRef(ABC):
+    @property
+    @abstractmethod
+    def dataset(self) -> LanceDataset:
+        pass
+
+    @property
+    @abstractmethod
+    def dataset_mut(self) -> LanceDataset:
+        pass
+
+
+@dataclass
+class _LanceLatestDatasetRef(_LanceDatasetRef):
+    """Reference to the latest version of a LanceDataset."""
+
+    uri: str
+    read_consistency_interval: Optional[timedelta] = None
+    last_consistency_check: Optional[float] = None
+    _dataset: Optional[LanceDataset] = None
+
+    @property
+    def dataset(self) -> LanceDataset:
+        if not self._dataset:
+            self._dataset = lance.dataset(self.uri)
+            self.last_consistency_check = time.monotonic()
+        elif self.read_consistency_interval is not None:
+            now = time.monotonic()
+            diff = timedelta(seconds=now - self.last_consistency_check)
+            if (
+                self.last_consistency_check is None
+                or diff > self.read_consistency_interval
+            ):
+                self._dataset = self._dataset.checkout_version(
+                    self._dataset.latest_version
+                )
+                self.last_consistency_check = time.monotonic()
+        return self._dataset
+
+    @dataset.setter
+    def dataset(self, value: LanceDataset):
+        self._dataset = value
+        self.last_consistency_check = time.monotonic()
+
+    @property
+    def dataset_mut(self) -> LanceDataset:
+        return self.dataset
+
+
+@dataclass
+class _LanceTimeTravelRef(_LanceDatasetRef):
+    uri: str
+    version: int
+    _dataset: Optional[LanceDataset] = None
+
+    @property
+    def dataset(self) -> LanceDataset:
+        if not self._dataset:
+            self._dataset = lance.dataset(self.uri, version=self.version)
+        return self._dataset
+
+    @dataset.setter
+    def dataset(self, value: LanceDataset):
+        self._dataset = value
+        self.version = value.version
+
+    @property
+    def dataset_mut(self) -> LanceDataset:
+        raise ValueError(
+            "Cannot mutate table reference fixed at version "
+            f"{self.version}. Call checkout_latest() to get a mutable "
+            "table reference."
+        )
+
+
 class LanceTable(Table):
     """
     A table in a LanceDB database.
+
+    This can be opened in two modes: standard and time-travel.
+
+    Standard mode is the default. In this mode, the table is mutable and tracks
+    the latest version of the table. The level of read consistency is controlled
+    by the `read_consistency_interval` parameter on the connection.
+
+    Time-travel mode is activated by specifying a version number. In this mode,
+    the table is immutable and fixed to a specific version. This is useful for
+    querying historical versions of the table.
     """
 
-    def __init__(self, connection: "LanceDBConnection", name: str, version: int = None):
+    def __init__(
+        self,
+        connection: "LanceDBConnection",
+        name: str,
+        version: Optional[int] = None,
+    ):
         self._conn = connection
         self.name = name
-        self._version = version
 
-    def _reset_dataset(self, version=None):
+        if version is not None:
-        try:
+            self._ref = _LanceTimeTravelRef(
-            if "_dataset" in self.__dict__:
+                uri=self._dataset_uri,
-                del self.__dict__["_dataset"]
+                version=version,
-            self._version = version
+            )
-        except AttributeError:
+        else:
-            pass
+            self._ref = _LanceLatestDatasetRef(
+                uri=self._dataset_uri,
+                read_consistency_interval=connection.read_consistency_interval,
+            )
+
+    @classmethod
+    def open(cls, db, name, **kwargs):
+        tbl = cls(db, name, **kwargs)
+        fs, path = fs_from_uri(tbl._dataset_uri)
+        file_info = fs.get_file_info(path)
+        if file_info.type != pa.fs.FileType.Directory:
+            raise FileNotFoundError(
+                f"Table {name} does not exist."
+                f"Please first call db.create_table({name}, data)"
+            )
+        register_event("open_table")
+
+        return tbl
+
+    @property
+    def _dataset_uri(self) -> str:
+        return join_uri(self._conn.uri, f"{self.name}.lance")
+
+    @property
+    def _dataset(self) -> LanceDataset:
+        return self._ref.dataset
+
+    @property
+    def _dataset_mut(self) -> LanceDataset:
+        return self._ref.dataset_mut
+
+    def to_lance(self) -> LanceDataset:
+        """Return the LanceDataset backing this table."""
+        return self._dataset
 
     @property
     def schema(self) -> pa.Schema:
@@ -686,6 +809,9 @@ class LanceTable(Table):
         keep writing to the dataset starting from an old version, then use
         the `restore` function.
 
+        Calling this method will set the table into time-travel mode. If you
+        wish to return to standard mode, call `checkout_latest`.
+
         Parameters
         ----------
         version : int
@@ -710,15 +836,13 @@ class LanceTable(Table):
                vector    type
         0  [1.1, 0.9]  vector
         """
-        max_ver = max([v["version"] for v in self._dataset.versions()])
+        max_ver = self._dataset.latest_version
         if version < 1 or version > max_ver:
             raise ValueError(f"Invalid version {version}")
-        self._reset_dataset(version=version)
 
         try:
-            # Accessing the property updates the cached value
+            ds = self._dataset.checkout_version(version)
-            _ = self._dataset
+        except IOError as e:
-        except Exception as e:
             if "not found" in str(e):
                 raise ValueError(
                     f"Version {version} no longer exists. Was it cleaned up?"
@@ -726,6 +850,27 @@ class LanceTable(Table):
             else:
                 raise e
 
+        self._ref = _LanceTimeTravelRef(
+            uri=self._dataset_uri,
+            version=version,
+        )
+        # We've already loaded the version so we can populate it directly.
+        self._ref.dataset = ds
+
+    def checkout_latest(self):
+        """Checkout the latest version of the table. This is an in-place operation.
+
+        The table will be set back into standard mode, and will track the latest
+        version of the table.
+        """
+        self.checkout(self._dataset.latest_version)
+        ds = self._ref.dataset
+        self._ref = _LanceLatestDatasetRef(
+            uri=self._dataset_uri,
+            read_consistency_interval=self._conn.read_consistency_interval,
+        )
+        self._ref.dataset = ds
+
     def restore(self, version: int = None):
         """Restore a version of the table. This is an in-place operation.
 
@@ -760,7 +905,7 @@ class LanceTable(Table):
         >>> len(table.list_versions())
         4
         """
-        max_ver = max([v["version"] for v in self._dataset.versions()])
+        max_ver = self._dataset.latest_version
         if version is None:
             version = self.version
         elif version < 1 or version > max_ver:
@@ -768,12 +913,17 @@ class LanceTable(Table):
         else:
             self.checkout(version)
 
-        if version == max_ver:
+        ds = self._dataset
-            # no-op if restoring the latest version
-            return
 
-        self._dataset.restore()
+        # no-op if restoring the latest version
-        self._reset_dataset()
+        if version != max_ver:
+            ds.restore()
+
+        self._ref = _LanceLatestDatasetRef(
+            uri=self._dataset_uri,
+            read_consistency_interval=self._conn.read_consistency_interval,
+        )
+        self._ref.dataset = ds
 
     def count_rows(self, filter: Optional[str] = None) -> int:
         """
@@ -790,7 +940,11 @@ class LanceTable(Table):
         return self.count_rows()
 
     def __repr__(self) -> str:
-        return f"LanceTable({self.name})"
+        val = f'{self.__class__.__name__}(connection={self._conn!r}, name="{self.name}"'
+        if isinstance(self._ref, _LanceTimeTravelRef):
+            val += f", version={self._ref.version}"
+        val += ")"
+        return val
 
     def __str__(self) -> str:
         return self.__repr__()
@@ -840,10 +994,6 @@ class LanceTable(Table):
             self.to_lance(), allow_pyarrow_filter=False, batch_size=batch_size
         )
 
-    @property
-    def _dataset_uri(self) -> str:
-        return join_uri(self._conn.uri, f"{self.name}.lance")
-
     def create_index(
         self,
         metric="L2",
@@ -855,7 +1005,7 @@ class LanceTable(Table):
         index_cache_size: Optional[int] = None,
     ):
         """Create an index on the table."""
-        self._dataset.create_index(
+        self._dataset_mut.create_index(
             column=vector_column_name,
             index_type="IVF_PQ",
             metric=metric,
@@ -865,11 +1015,12 @@ class LanceTable(Table):
             accelerator=accelerator,
             index_cache_size=index_cache_size,
         )
-        self._reset_dataset()
         register_event("create_index")
 
     def create_scalar_index(self, column: str, *, replace: bool = True):
-        self._dataset.create_scalar_index(column, index_type="BTREE", replace=replace)
+        self._dataset_mut.create_scalar_index(
+            column, index_type="BTREE", replace=replace
+        )
 
     def create_fts_index(
         self,
@@ -912,14 +1063,6 @@ class LanceTable(Table):
     def _get_fts_index_path(self):
         return join_uri(self._dataset_uri, "_indices", "tantivy")
 
-    @cached_property
-    def _dataset(self) -> LanceDataset:
-        return lance.dataset(self._dataset_uri, version=self._version)
-
-    def to_lance(self) -> LanceDataset:
-        """Return the LanceDataset backing this table."""
-        return self._dataset
-
     def add(
         self,
         data: DATA,
@@ -958,8 +1101,11 @@ class LanceTable(Table):
             on_bad_vectors=on_bad_vectors,
             fill_value=fill_value,
         )
-        lance.write_dataset(data, self._dataset_uri, schema=self.schema, mode=mode)
+        # Access the dataset_mut property to ensure that the dataset is mutable.
-        self._reset_dataset()
+        self._ref.dataset_mut
+        self._ref.dataset = lance.write_dataset(
+            data, self._dataset_uri, schema=self.schema, mode=mode
+        )
         register_event("add")
 
     def merge(
@@ -1020,10 +1166,9 @@ class LanceTable(Table):
             other_table = other_table.to_lance()
         if isinstance(other_table, LanceDataset):
             other_table = other_table.to_table()
-        self._dataset.merge(
+        self._ref.dataset = self._dataset_mut.merge(
             other_table, left_on=left_on, right_on=right_on, schema=schema
         )
-        self._reset_dataset()
         register_event("merge")
 
     @cached_property
@@ -1226,22 +1371,8 @@ class LanceTable(Table):
         register_event("create_table")
         return new_table
 
-    @classmethod
-    def open(cls, db, name):
-        tbl = cls(db, name)
-        fs, path = fs_from_uri(tbl._dataset_uri)
-        file_info = fs.get_file_info(path)
-        if file_info.type != pa.fs.FileType.Directory:
-            raise FileNotFoundError(
-                f"Table {name} does not exist."
-                f"Please first call db.create_table({name}, data)"
-            )
-        register_event("open_table")
-
-        return tbl
-
     def delete(self, where: str):
-        self._dataset.delete(where)
+        self._dataset_mut.delete(where)
 
     def update(
         self,
@@ -1295,8 +1426,7 @@ class LanceTable(Table):
         if values is not None:
             values_sql = {k: value_to_sql(v) for k, v in values.items()}
 
-        self.to_lance().update(values_sql, where)
+        self._dataset_mut.update(values_sql, where)
-        self._reset_dataset()
         register_event("update")
 
     def _execute_query(self, query: Query) -> pa.Table:

python/pyproject.toml

@@ -48,7 +48,7 @@ classifiers = [
 repository = "https://github.com/lancedb/lancedb"
 
 [project.optional-dependencies]
-tests = ["aiohttp", "pandas>=1.4", "pytest", "pytest-mock", "pytest-asyncio", "duckdb", "pytz", "polars"]
+tests = ["aiohttp", "pandas>=1.4", "pytest", "pytest-mock", "pytest-asyncio", "duckdb", "pytz", "polars>=0.19"]
 dev = ["ruff", "pre-commit"]
 docs = ["mkdocs", "mkdocs-jupyter", "mkdocs-material", "mkdocstrings[python]"]
 clip = ["torch", "pillow", "open-clip"]

python/tests/test_embeddings.py

@@ -88,6 +88,7 @@ def test_embedding_function(tmp_path):
     assert np.allclose(actual, expected)
 
 
+@pytest.mark.slow
 def test_embedding_function_rate_limit(tmp_path):
     def _get_schema_from_model(model):
         class Schema(LanceModel):

python/tests/test_table.py

@@ -12,8 +12,10 @@
 #  limitations under the License.
 
 import functools
+from copy import copy
 from datetime import date, datetime, timedelta
 from pathlib import Path
+from time import sleep
 from typing import List
 from unittest.mock import PropertyMock, patch
 
@@ -25,6 +27,7 @@ import pyarrow as pa
 import pytest
 from pydantic import BaseModel
 
+import lancedb
 from lancedb.conftest import MockTextEmbeddingFunction
 from lancedb.db import LanceDBConnection
 from lancedb.embeddings import EmbeddingFunctionConfig, EmbeddingFunctionRegistry
@@ -35,6 +38,7 @@ from lancedb.table import LanceTable
 class MockDB:
     def __init__(self, uri: Path):
         self.uri = uri
+        self.read_consistency_interval = None
 
     @functools.cached_property
     def is_managed_remote(self) -> bool:
@@ -267,39 +271,38 @@ def test_versioning(db):
 
 
 def test_create_index_method():
-    with patch.object(LanceTable, "_reset_dataset", return_value=None):
+    with patch.object(
-        with patch.object(
+        LanceTable, "_dataset_mut", new_callable=PropertyMock
-            LanceTable, "_dataset", new_callable=PropertyMock
+    ) as mock_dataset:
-        ) as mock_dataset:
+        # Setup mock responses
-            # Setup mock responses
+        mock_dataset.return_value.create_index.return_value = None
-            mock_dataset.return_value.create_index.return_value = None
 
-            # Create a LanceTable object
+        # Create a LanceTable object
-            connection = LanceDBConnection(uri="mock.uri")
+        connection = LanceDBConnection(uri="mock.uri")
-            table = LanceTable(connection, "test_table")
+        table = LanceTable(connection, "test_table")
 
-            # Call the create_index method
+        # Call the create_index method
-            table.create_index(
+        table.create_index(
-                metric="L2",
+            metric="L2",
-                num_partitions=256,
+            num_partitions=256,
-                num_sub_vectors=96,
+            num_sub_vectors=96,
-                vector_column_name="vector",
+            vector_column_name="vector",
-                replace=True,
+            replace=True,
-                index_cache_size=256,
+            index_cache_size=256,
-            )
+        )
 
-            # Check that the _dataset.create_index method was called
+        # Check that the _dataset.create_index method was called
-            # with the right parameters
+        # with the right parameters
-            mock_dataset.return_value.create_index.assert_called_once_with(
+        mock_dataset.return_value.create_index.assert_called_once_with(
-                column="vector",
+            column="vector",
-                index_type="IVF_PQ",
+            index_type="IVF_PQ",
-                metric="L2",
+            metric="L2",
-                num_partitions=256,
+            num_partitions=256,
-                num_sub_vectors=96,
+            num_sub_vectors=96,
-                replace=True,
+            replace=True,
-                accelerator=None,
+            accelerator=None,
-                index_cache_size=256,
+            index_cache_size=256,
-            )
+        )
 
 
 def test_add_with_nans(db):
@@ -792,3 +795,48 @@ def test_hybrid_search(db):
         "Our father who art in heaven", query_type="hybrid"
     ).to_pydantic(MyTable)
     assert result1 == result3
+
+
+@pytest.mark.parametrize(
+    "consistency_interval", [None, timedelta(seconds=0), timedelta(seconds=0.1)]
+)
+def test_consistency(tmp_path, consistency_interval):
+    db = lancedb.connect(tmp_path)
+    table = LanceTable.create(db, "my_table", data=[{"id": 0}])
+
+    db2 = lancedb.connect(tmp_path, read_consistency_interval=consistency_interval)
+    table2 = db2.open_table("my_table")
+    assert table2.version == table.version
+
+    table.add([{"id": 1}])
+
+    if consistency_interval is None:
+        assert table2.version == table.version - 1
+        table2.checkout_latest()
+        assert table2.version == table.version
+    elif consistency_interval == timedelta(seconds=0):
+        assert table2.version == table.version
+    else:
+        # (consistency_interval == timedelta(seconds=0.1)
+        assert table2.version == table.version - 1
+        sleep(0.1)
+        assert table2.version == table.version
+
+
+def test_restore_consistency(tmp_path):
+    db = lancedb.connect(tmp_path)
+    table = LanceTable.create(db, "my_table", data=[{"id": 0}])
+
+    db2 = lancedb.connect(tmp_path, read_consistency_interval=timedelta(seconds=0))
+    table2 = db2.open_table("my_table")
+    assert table2.version == table.version
+
+    # If we call checkout, it should lose consistency
+    table_fixed = copy(table2)
+    table_fixed.checkout(table.version)
+    # But if we call checkout_latest, it should be consistent again
+    table_ref_latest = copy(table_fixed)
+    table_ref_latest.checkout_latest()
+    table.add([{"id": 2}])
+    assert table_fixed.version == table.version - 1
+    assert table_ref_latest.version == table.version