feat: expose use_index in LanceDB OSS

python/lancedb/query.py

@@ -59,6 +59,8 @@ class Query(pydantic.BaseModel):
     # Refine factor.
     refine_factor: Optional[int] = None
 
+    use_index: bool = True
+
 
 class LanceQueryBuilder(ABC):
     @classmethod
@@ -279,6 +281,7 @@ class LanceVectorQueryBuilder(LanceQueryBuilder):
         self._refine_factor = None
         self._vector_column = vector_column
         self._prefilter = False
+        self._use_index = True
 
     def metric(self, metric: Literal["L2", "cosine"]) -> LanceVectorQueryBuilder:
         """Set the distance metric to use.
@@ -340,6 +343,21 @@ class LanceVectorQueryBuilder(LanceQueryBuilder):
         self._refine_factor = refine_factor
         return self
 
+    def use_index(self, use_index: bool) -> LanceVectorQueryBuilder:
+        """
+        Choose whether to use an ANN index or not. Default is True.
+
+        Setting this to False is not yet supported on LanceDB Cloud.
+
+        Parameters
+        ----------
+        use_index: bool
+            If True, use an ANN index if one exists, otherwise perform exact KNN
+            on a full table scan.
+        """
+        self._use_index = use_index
+        return self
+
     def to_arrow(self) -> pa.Table:
         """
         Execute the query and return the results as an
@@ -360,6 +378,7 @@ class LanceVectorQueryBuilder(LanceQueryBuilder):
             nprobes=self._nprobes,
             refine_factor=self._refine_factor,
             vector_column=self._vector_column,
+            use_index=self._use_index,
         )
         return self._table._execute_query(query)
 

python/lancedb/remote/table.py

@@ -101,6 +101,10 @@ class RemoteTable(Table):
     def _execute_query(self, query: Query) -> pa.Table:
         if query.prefilter:
             raise NotImplementedError("Cloud support for prefiltering is coming soon")
+        if not query.use_index:
+            raise NotImplementedError(
+                "Cloud does not support non-indexed queries if the table has indices"
+            )
         result = self._conn._client.query(self._name, query)
         return self._conn._loop.run_until_complete(result).to_arrow()
 

python/lancedb/table.py

@@ -559,7 +559,8 @@ class LanceTable(Table):
             The data to insert into the table.
         mode: str
             The mode to use when writing the data. Valid values are
-            "append" and "overwrite".
+            "append", which inserts new rows, and "overwrite", which replaces
+            the entire content of the table with the new rows.
         on_bad_vectors: str, default "error"
             What to do if any of the vectors are not the same size or contains NaNs.
             One of "error", "drop", "fill".
@@ -887,6 +888,7 @@ class LanceTable(Table):
                 "metric": query.metric,
                 "nprobes": query.nprobes,
                 "refine_factor": query.refine_factor,
+                "use_index": query.use_index,
             },
         )
 

python/tests/test_query.py

@@ -46,6 +46,7 @@ class MockTable:
                 "metric": query.metric,
                 "nprobes": query.nprobes,
                 "refine_factor": query.refine_factor,
+                "use_index": query.use_index,
             },
         )
 
@@ -84,10 +85,12 @@ def test_cast(table):
     assert r0.float_field == 1.0
 
 
-def test_query_builder(table):
+@pytest.mark.parametrize("use_index", [True, False])
+def test_query_builder(table, use_index: bool):
     rs = (
         LanceVectorQueryBuilder(table, [0, 0], "vector")
         .limit(1)
+        .use_index(use_index)
         .select(["id"])
         .to_list()
     )