chore: upgrade lance to stable 4.0.0 (#3207)

Bumps all lance-* workspace dependencies from `4.0.0-rc.3` (git source)
to the stable `4.0.0` release on crates.io, removing the `git`/`tag`
overrides.

No code changes were required — compiles and passes clippy cleanly.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

.bumpversion.toml

@@ -1,5 +1,5 @@
 [tool.bumpversion]
-current_version = "0.27.0"
+current_version = "0.27.2-beta.1"
 parse = """(?x)
     (?P<major>0|[1-9]\\d*)\\.
     (?P<minor>0|[1-9]\\d*)\\.

.github/workflows/build_linux_wheel/action.yml

@@ -23,8 +23,10 @@ runs:
   steps:
     - name: CONFIRM ARM BUILD
       shell: bash
+      env:
+        ARM_BUILD: ${{ inputs.arm-build }}
       run: |
-        echo "ARM BUILD: ${{ inputs.arm-build }}"
+        echo "ARM BUILD: $ARM_BUILD"
     - name: Build x86_64 Manylinux wheel
       if: ${{ inputs.arm-build == 'false' }}
       uses: PyO3/maturin-action@v1

.github/workflows/rust.yml

@@ -207,14 +207,14 @@ jobs:
       - name: Downgrade  dependencies
         # These packages have newer requirements for MSRV
         run: |
-          cargo update -p aws-sdk-bedrockruntime --precise 1.64.0
+          cargo update -p aws-sdk-bedrockruntime --precise 1.77.0
-          cargo update -p aws-sdk-dynamodb --precise 1.55.0
+          cargo update -p aws-sdk-dynamodb --precise 1.68.0
-          cargo update -p aws-config --precise 1.5.10
+          cargo update -p aws-config --precise 1.6.0
-          cargo update -p aws-sdk-kms --precise 1.51.0
+          cargo update -p aws-sdk-kms --precise 1.63.0
-          cargo update -p aws-sdk-s3 --precise 1.65.0
+          cargo update -p aws-sdk-s3 --precise 1.79.0
-          cargo update -p aws-sdk-sso --precise 1.50.0
+          cargo update -p aws-sdk-sso --precise 1.62.0
-          cargo update -p aws-sdk-ssooidc --precise 1.51.0
+          cargo update -p aws-sdk-ssooidc --precise 1.63.0
-          cargo update -p aws-sdk-sts --precise 1.51.0
+          cargo update -p aws-sdk-sts --precise 1.63.0
           cargo update -p home --precise 0.5.9
       - name: cargo +${{ matrix.msrv }} check
         env:

Cargo.toml

@@ -15,20 +15,20 @@ categories = ["database-implementations"]
 rust-version = "1.91.0"
 
 [workspace.dependencies]
-lance = { version = "=3.0.1", default-features = false }
+lance = { version = "=4.0.0", default-features = false }
-lance-core = { version = "=3.0.1" }
+lance-core = { version = "=4.0.0" }
-lance-datagen = { version = "=3.0.1" }
+lance-datagen = { version = "=4.0.0" }
-lance-file = { version = "=3.0.1" }
+lance-file = { version = "=4.0.0" }
-lance-io = { version = "=3.0.1", default-features = false }
+lance-io = { version = "=4.0.0", default-features = false }
-lance-index = { version = "=3.0.1" }
+lance-index = { version = "=4.0.0" }
-lance-linalg = { version = "=3.0.1" }
+lance-linalg = { version = "=4.0.0" }
-lance-namespace = { version = "=3.0.1" }
+lance-namespace = { version = "=4.0.0" }
-lance-namespace-impls = { version = "=3.0.1", default-features = false }
+lance-namespace-impls = { version = "=4.0.0", default-features = false }
-lance-table = { version = "=3.0.1" }
+lance-table = { version = "=4.0.0" }
-lance-testing = { version = "=3.0.1" }
+lance-testing = { version = "=4.0.0" }
-lance-datafusion = { version = "=3.0.1" }
+lance-datafusion = { version = "=4.0.0" }
-lance-encoding = { version = "=3.0.1" }
+lance-encoding = { version = "=4.0.0" }
-lance-arrow = { version = "=3.0.1" }
+lance-arrow = { version = "=4.0.0" }
 ahash = "0.8"
 # Note that this one does not include pyarrow
 arrow = { version = "57.2", optional = false }

docs/requirements.txt

@@ -1,8 +1,8 @@
-mkdocs==1.5.3
+mkdocs==1.6.1
 mkdocs-jupyter==0.24.1
-mkdocs-material==9.5.3
+mkdocs-material==9.6.23
 mkdocs-autorefs>=0.5,<=1.0
-mkdocstrings[python]==0.25.2
+mkdocstrings[python]>=0.24,<1.0
 griffe>=0.40,<1.0
 mkdocs-render-swagger-plugin>=0.1.0
 pydantic>=2.0,<3.0

docs/src/java/java.md

@@ -14,7 +14,7 @@ Add the following dependency to your `pom.xml`:
 <dependency>
     <groupId>com.lancedb</groupId>
     <artifactId>lancedb-core</artifactId>
-    <version>0.27.0</version>
+    <version>0.27.2-beta.1</version>
 </dependency>
 ```
 

docs/src/js/namespaces/embedding/classes/EmbeddingFunction.md

@@ -52,7 +52,7 @@ new EmbeddingFunction<T, M>(): EmbeddingFunction<T, M>
 ### computeQueryEmbeddings()
 
 ```ts
-computeQueryEmbeddings(data): Promise<number[] | Float32Array | Float64Array>
+computeQueryEmbeddings(data): Promise<number[] | Uint8Array | Float32Array | Float64Array>
 ```
 
 Compute the embeddings for a single query
@@ -63,7 +63,7 @@ Compute the embeddings for a single query
 
 #### Returns
 
-`Promise`&lt;`number`[] \| `Float32Array` \| `Float64Array`&gt;
+`Promise`&lt;`number`[] \| `Uint8Array` \| `Float32Array` \| `Float64Array`&gt;
 
 ***
 

docs/src/js/namespaces/embedding/classes/TextEmbeddingFunction.md

@@ -37,7 +37,7 @@ new TextEmbeddingFunction<M>(): TextEmbeddingFunction<M>
 ### computeQueryEmbeddings()
 
 ```ts
-computeQueryEmbeddings(data): Promise<number[] | Float32Array | Float64Array>
+computeQueryEmbeddings(data): Promise<number[] | Uint8Array | Float32Array | Float64Array>
 ```
 
 Compute the embeddings for a single query
@@ -48,7 +48,7 @@ Compute the embeddings for a single query
 
 #### Returns
 
-`Promise`&lt;`number`[] \| `Float32Array` \| `Float64Array`&gt;
+`Promise`&lt;`number`[] \| `Uint8Array` \| `Float32Array` \| `Float64Array`&gt;
 
 #### Overrides
 

docs/src/js/type-aliases/IntoVector.md

@@ -7,5 +7,10 @@
 # Type Alias: IntoVector
 
 ```ts
-type IntoVector: Float32Array | Float64Array | number[] | Promise<Float32Array | Float64Array | number[]>;
+type IntoVector:
+  | Float32Array
+  | Float64Array
+  | Uint8Array
+  | number[]
+  | Promise<Float32Array | Float64Array | Uint8Array | number[]>;
 ```

java/lancedb-core/pom.xml

@@ -8,7 +8,7 @@
     <parent>
       <groupId>com.lancedb</groupId>
       <artifactId>lancedb-parent</artifactId>
-      <version>0.27.0-final.0</version>
+      <version>0.27.2-beta.1</version>
       <relativePath>../pom.xml</relativePath>
     </parent>
 

java/pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.lancedb</groupId>
     <artifactId>lancedb-parent</artifactId>
-    <version>0.27.0-final.0</version>
+    <version>0.27.2-beta.1</version>
     <packaging>pom</packaging>
     <name>${project.artifactId}</name>
     <description>LanceDB Java SDK Parent POM</description>
@@ -28,7 +28,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <arrow.version>15.0.0</arrow.version>
-        <lance-core.version>3.1.0-beta.2</lance-core.version>
+        <lance-core.version>3.0.1</lance-core.version>
         <spotless.skip>false</spotless.skip>
         <spotless.version>2.30.0</spotless.version>
         <spotless.java.googlejavaformat.version>1.7</spotless.java.googlejavaformat.version>

nodejs/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "lancedb-nodejs"
 edition.workspace = true
-version = "0.27.0"
+version = "0.27.2-beta.1"
 license.workspace = true
 description.workspace = true
 repository.workspace = true
@@ -15,6 +15,8 @@ crate-type = ["cdylib"]
 async-trait.workspace = true
 arrow-ipc.workspace = true
 arrow-array.workspace = true
+arrow-buffer = "57.2"
+half.workspace = true
 arrow-schema.workspace = true
 env_logger.workspace = true
 futures.workspace = true

nodejs/__test__/vector_types.test.ts

@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright The LanceDB Authors
+
+import * as tmp from "tmp";
+
+import { type Table, connect } from "../lancedb";
+import {
+  Field,
+  FixedSizeList,
+  Float32,
+  Int64,
+  Schema,
+  makeArrowTable,
+} from "../lancedb/arrow";
+
+describe("Vector query with different typed arrays", () => {
+  let tmpDir: tmp.DirResult;
+
+  afterEach(() => {
+    tmpDir?.removeCallback();
+  });
+
+  async function createFloat32Table(): Promise<Table> {
+    tmpDir = tmp.dirSync({ unsafeCleanup: true });
+    const db = await connect(tmpDir.name);
+    const schema = new Schema([
+      new Field("id", new Int64(), true),
+      new Field(
+        "vec",
+        new FixedSizeList(2, new Field("item", new Float32())),
+        true,
+      ),
+    ]);
+    const data = makeArrowTable(
+      [
+        { id: 1n, vec: [1.0, 0.0] },
+        { id: 2n, vec: [0.0, 1.0] },
+        { id: 3n, vec: [1.0, 1.0] },
+      ],
+      { schema },
+    );
+    return db.createTable("test_f32", data);
+  }
+
+  it("should search with Float32Array (baseline)", async () => {
+    const table = await createFloat32Table();
+    const results = await table
+      .query()
+      .nearestTo(new Float32Array([1.0, 0.0]))
+      .limit(1)
+      .toArray();
+
+    expect(results.length).toBe(1);
+    expect(Number(results[0].id)).toBe(1);
+  });
+
+  it("should search with number[] (backward compat)", async () => {
+    const table = await createFloat32Table();
+    const results = await table
+      .query()
+      .nearestTo([1.0, 0.0])
+      .limit(1)
+      .toArray();
+
+    expect(results.length).toBe(1);
+    expect(Number(results[0].id)).toBe(1);
+  });
+
+  it("should search with Float64Array via raw path", async () => {
+    const table = await createFloat32Table();
+    const results = await table
+      .query()
+      .nearestTo(new Float64Array([1.0, 0.0]))
+      .limit(1)
+      .toArray();
+
+    expect(results.length).toBe(1);
+    expect(Number(results[0].id)).toBe(1);
+  });
+
+  it("should add multiple query vectors with Float64Array", async () => {
+    const table = await createFloat32Table();
+    const results = await table
+      .query()
+      .nearestTo(new Float64Array([1.0, 0.0]))
+      .addQueryVector(new Float64Array([0.0, 1.0]))
+      .limit(2)
+      .toArray();
+
+    expect(results.length).toBeGreaterThanOrEqual(2);
+  });
+
+  // Float16Array is only available in Node 22+; not in TypeScript's standard lib yet
+  const float16ArrayCtor = (globalThis as unknown as Record<string, unknown>)
+    .Float16Array as (new (values: number[]) => unknown) | undefined;
+  const hasFloat16 = float16ArrayCtor !== undefined;
+  const f16it = hasFloat16 ? it : it.skip;
+
+  f16it("should search with Float16Array via raw path", async () => {
+    const table = await createFloat32Table();
+    const results = await table
+      .query()
+      .nearestTo(new float16ArrayCtor!([1.0, 0.0]) as Float32Array)
+      .limit(1)
+      .toArray();
+
+    expect(results.length).toBe(1);
+    expect(Number(results[0].id)).toBe(1);
+  });
+});

nodejs/lancedb/arrow.ts

@@ -117,8 +117,9 @@ export type TableLike =
 export type IntoVector =
   | Float32Array
   | Float64Array
+  | Uint8Array
   | number[]
-  | Promise<Float32Array | Float64Array | number[]>;
+  | Promise<Float32Array | Float64Array | Uint8Array | number[]>;
 
 export type MultiVector = IntoVector[];
 
@@ -126,14 +127,48 @@ export function isMultiVector(value: unknown): value is MultiVector {
   return Array.isArray(value) && isIntoVector(value[0]);
 }
 
+// Float16Array is not in TypeScript's standard lib yet; access dynamically
+type Float16ArrayCtor = new (
+  ...args: unknown[]
+) => { buffer: ArrayBuffer; byteOffset: number; byteLength: number };
+const float16ArrayCtor = (globalThis as unknown as Record<string, unknown>)
+  .Float16Array as Float16ArrayCtor | undefined;
+
 export function isIntoVector(value: unknown): value is IntoVector {
   return (
     value instanceof Float32Array ||
     value instanceof Float64Array ||
+    value instanceof Uint8Array ||
+    (float16ArrayCtor !== undefined && value instanceof float16ArrayCtor) ||
     (Array.isArray(value) && !Array.isArray(value[0]))
   );
 }
 
+/**
+ * Extract the underlying byte buffer and data type from a typed array
+ * for passing to the Rust NAPI layer without precision loss.
+ */
+export function extractVectorBuffer(
+  vector: Float32Array | Float64Array | Uint8Array,
+): { data: Uint8Array; dtype: string } | null {
+  if (float16ArrayCtor !== undefined && vector instanceof float16ArrayCtor) {
+    return {
+      data: new Uint8Array(vector.buffer, vector.byteOffset, vector.byteLength),
+      dtype: "float16",
+    };
+  }
+  if (vector instanceof Float64Array) {
+    return {
+      data: new Uint8Array(vector.buffer, vector.byteOffset, vector.byteLength),
+      dtype: "float64",
+    };
+  }
+  if (vector instanceof Uint8Array && !(vector instanceof Float32Array)) {
+    return { data: vector, dtype: "uint8" };
+  }
+  return null;
+}
+
 export function isArrowTable(value: object): value is TableLike {
   if (value instanceof ArrowTable) return true;
   return "schema" in value && "batches" in value;

nodejs/lancedb/query.ts

@@ -5,6 +5,7 @@ import {
   Table as ArrowTable,
   type IntoVector,
   RecordBatch,
+  extractVectorBuffer,
   fromBufferToRecordBatch,
   fromRecordBatchToBuffer,
   tableFromIPC,
@@ -661,10 +662,8 @@ export class VectorQuery extends StandardQueryBase<NativeVectorQuery> {
       const res = (async () => {
         try {
           const v = await vector;
-          const arr = Float32Array.from(v);
-          //
           // biome-ignore lint/suspicious/noExplicitAny: we need to get the `inner`, but js has no package scoping
-          const value: any = this.addQueryVector(arr);
+          const value: any = this.addQueryVector(v);
           const inner = value.inner as
             | NativeVectorQuery
             | Promise<NativeVectorQuery>;
@@ -676,7 +675,12 @@ export class VectorQuery extends StandardQueryBase<NativeVectorQuery> {
       return new VectorQuery(res);
     } else {
       super.doCall((inner) => {
-        inner.addQueryVector(Float32Array.from(vector));
+        const raw = Array.isArray(vector) ? null : extractVectorBuffer(vector);
+        if (raw) {
+          inner.addQueryVectorRaw(raw.data, raw.dtype);
+        } else {
+          inner.addQueryVector(Float32Array.from(vector as number[]));
+        }
       });
       return this;
     }
@@ -765,14 +769,23 @@ export class Query extends StandardQueryBase<NativeQuery> {
    * a default `limit` of 10 will be used.  @see {@link Query#limit}
    */
   nearestTo(vector: IntoVector): VectorQuery {
+    const callNearestTo = (
+      inner: NativeQuery,
+      resolved: Float32Array | Float64Array | Uint8Array | number[],
+    ): NativeVectorQuery => {
+      const raw = Array.isArray(resolved)
+        ? null
+        : extractVectorBuffer(resolved);
+      if (raw) {
+        return inner.nearestToRaw(raw.data, raw.dtype);
+      }
+      return inner.nearestTo(Float32Array.from(resolved as number[]));
+    };
+
     if (this.inner instanceof Promise) {
       const nativeQuery = this.inner.then(async (inner) => {
-        if (vector instanceof Promise) {
+        const resolved = vector instanceof Promise ? await vector : vector;
-          const arr = await vector.then((v) => Float32Array.from(v));
+        return callNearestTo(inner, resolved);
-          return inner.nearestTo(arr);
-        } else {
-          return inner.nearestTo(Float32Array.from(vector));
-        }
       });
       return new VectorQuery(nativeQuery);
     }
@@ -780,10 +793,8 @@ export class Query extends StandardQueryBase<NativeQuery> {
       const res = (async () => {
         try {
           const v = await vector;
-          const arr = Float32Array.from(v);
-          //
           // biome-ignore lint/suspicious/noExplicitAny: we need to get the `inner`, but js has no package scoping
-          const value: any = this.nearestTo(arr);
+          const value: any = this.nearestTo(v);
           const inner = value.inner as
             | NativeVectorQuery
             | Promise<NativeVectorQuery>;
@@ -794,7 +805,7 @@ export class Query extends StandardQueryBase<NativeQuery> {
       })();
       return new VectorQuery(res);
     } else {
-      const vectorQuery = this.inner.nearestTo(Float32Array.from(vector));
+      const vectorQuery = callNearestTo(this.inner, vector);
       return new VectorQuery(vectorQuery);
     }
   }

nodejs/npm/darwin-arm64/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-darwin-arm64",
-	"version": "0.27.0",
+	"version": "0.27.2-beta.1",
 	"os": ["darwin"],
 	"cpu": ["arm64"],
 	"main": "lancedb.darwin-arm64.node",

nodejs/npm/linux-arm64-gnu/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-arm64-gnu",
-	"version": "0.27.0",
+	"version": "0.27.2-beta.1",
 	"os": ["linux"],
 	"cpu": ["arm64"],
 	"main": "lancedb.linux-arm64-gnu.node",

nodejs/npm/linux-arm64-musl/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-arm64-musl",
-	"version": "0.27.0",
+	"version": "0.27.2-beta.1",
 	"os": ["linux"],
 	"cpu": ["arm64"],
 	"main": "lancedb.linux-arm64-musl.node",

nodejs/npm/linux-x64-gnu/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-x64-gnu",
-	"version": "0.27.0",
+	"version": "0.27.2-beta.1",
 	"os": ["linux"],
 	"cpu": ["x64"],
 	"main": "lancedb.linux-x64-gnu.node",

nodejs/npm/linux-x64-musl/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-x64-musl",
-	"version": "0.27.0",
+	"version": "0.27.2-beta.1",
 	"os": ["linux"],
 	"cpu": ["x64"],
 	"main": "lancedb.linux-x64-musl.node",

nodejs/npm/win32-arm64-msvc/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lancedb/lancedb-win32-arm64-msvc",
-  "version": "0.27.0",
+  "version": "0.27.2-beta.1",
   "os": [
     "win32"
   ],

nodejs/npm/win32-x64-msvc/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-win32-x64-msvc",
-	"version": "0.27.0",
+	"version": "0.27.2-beta.1",
 	"os": ["win32"],
 	"cpu": ["x64"],
 	"main": "lancedb.win32-x64-msvc.node",

nodejs/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@lancedb/lancedb",
-  "version": "0.27.0",
+  "version": "0.27.2-beta.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@lancedb/lancedb",
-      "version": "0.27.0",
+      "version": "0.27.2-beta.1",
       "cpu": [
         "x64",
         "arm64"

nodejs/package.json

@@ -11,7 +11,7 @@
     "ann"
   ],
   "private": false,
-  "version": "0.27.0",
+  "version": "0.27.2-beta.1",
   "main": "dist/index.js",
   "exports": {
     ".": "./dist/index.js",

nodejs/src/query.rs

@@ -3,6 +3,12 @@
 
 use std::sync::Arc;
 
+use arrow_array::{
+    Array, Float16Array as ArrowFloat16Array, Float32Array as ArrowFloat32Array,
+    Float64Array as ArrowFloat64Array, UInt8Array as ArrowUInt8Array,
+};
+use arrow_buffer::ScalarBuffer;
+use half::f16;
 use lancedb::index::scalar::{
     BooleanQuery, BoostQuery, FtsQuery, FullTextSearchQuery, MatchQuery, MultiMatchQuery, Occur,
     Operator, PhraseQuery,
@@ -24,6 +30,33 @@ use crate::rerankers::RerankHybridCallbackArgs;
 use crate::rerankers::Reranker;
 use crate::util::{parse_distance_type, schema_to_buffer};
 
+fn bytes_to_arrow_array(data: Uint8Array, dtype: String) -> napi::Result<Arc<dyn Array>> {
+    let buf = arrow_buffer::Buffer::from(data.to_vec());
+    let num_bytes = buf.len();
+    match dtype.as_str() {
+        "float16" => {
+            let scalar_buf = ScalarBuffer::<f16>::new(buf, 0, num_bytes / 2);
+            Ok(Arc::new(ArrowFloat16Array::new(scalar_buf, None)))
+        }
+        "float32" => {
+            let scalar_buf = ScalarBuffer::<f32>::new(buf, 0, num_bytes / 4);
+            Ok(Arc::new(ArrowFloat32Array::new(scalar_buf, None)))
+        }
+        "float64" => {
+            let scalar_buf = ScalarBuffer::<f64>::new(buf, 0, num_bytes / 8);
+            Ok(Arc::new(ArrowFloat64Array::new(scalar_buf, None)))
+        }
+        "uint8" => {
+            let scalar_buf = ScalarBuffer::<u8>::new(buf, 0, num_bytes);
+            Ok(Arc::new(ArrowUInt8Array::new(scalar_buf, None)))
+        }
+        _ => Err(napi::Error::from_reason(format!(
+            "Unsupported vector dtype: {}. Expected one of: float16, float32, float64, uint8",
+            dtype
+        ))),
+    }
+}
+
 #[napi]
 pub struct Query {
     inner: LanceDbQuery,
@@ -78,6 +111,13 @@ impl Query {
         Ok(VectorQuery { inner })
     }
 
+    #[napi]
+    pub fn nearest_to_raw(&mut self, data: Uint8Array, dtype: String) -> Result<VectorQuery> {
+        let array = bytes_to_arrow_array(data, dtype)?;
+        let inner = self.inner.clone().nearest_to(array).default_error()?;
+        Ok(VectorQuery { inner })
+    }
+
     #[napi]
     pub fn fast_search(&mut self) {
         self.inner = self.inner.clone().fast_search();
@@ -163,6 +203,13 @@ impl VectorQuery {
         Ok(())
     }
 
+    #[napi]
+    pub fn add_query_vector_raw(&mut self, data: Uint8Array, dtype: String) -> Result<()> {
+        let array = bytes_to_arrow_array(data, dtype)?;
+        self.inner = self.inner.clone().add_query_vector(array).default_error()?;
+        Ok(())
+    }
+
     #[napi]
     pub fn distance_type(&mut self, distance_type: String) -> napi::Result<()> {
         let distance_type = parse_distance_type(distance_type)?;

python/.bumpversion.toml

@@ -1,5 +1,5 @@
 [tool.bumpversion]
-current_version = "0.30.1"
+current_version = "0.30.2-beta.1"
 parse = """(?x)
     (?P<major>0|[1-9]\\d*)\\.
     (?P<minor>0|[1-9]\\d*)\\.

python/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lancedb-python"
-version = "0.30.1"
+version = "0.30.2-beta.1"
 edition.workspace = true
 description = "Python bindings for LanceDB"
 license.workspace = true
@@ -23,6 +23,7 @@ lance-namespace.workspace = true
 lance-namespace-impls.workspace = true
 lance-io.workspace = true
 env_logger.workspace = true
+log.workspace = true
 pyo3 = { version = "0.26", features = ["extension-module", "abi3-py39"] }
 pyo3-async-runtimes = { version = "0.26", features = [
     "attributes",

python/python/lancedb/_lancedb.pyi

@@ -135,7 +135,10 @@ class Table:
     def close(self) -> None: ...
     async def schema(self) -> pa.Schema: ...
     async def add(
-        self, data: pa.RecordBatchReader, mode: Literal["append", "overwrite"]
+        self,
+        data: pa.RecordBatchReader,
+        mode: Literal["append", "overwrite"],
+        progress: Optional[Any] = None,
     ) -> AddResult: ...
     async def update(
         self, updates: Dict[str, str], where: Optional[str]

python/python/lancedb/embeddings/utils.py

@@ -10,6 +10,7 @@ import sys
 import threading
 import time
 import urllib.error
+import urllib.request
 import weakref
 import logging
 from functools import wraps

python/python/lancedb/query.py

@@ -70,7 +70,7 @@ def ensure_vector_query(
 ) -> Union[List[float], List[List[float]], pa.Array, List[pa.Array]]:
     if isinstance(val, list):
         if len(val) == 0:
-            return ValueError("Vector query must be a non-empty list")
+            raise ValueError("Vector query must be a non-empty list")
         sample = val[0]
     else:
         if isinstance(val, float):
@@ -83,7 +83,7 @@ def ensure_vector_query(
         return val
     if isinstance(sample, list):
         if len(sample) == 0:
-            return ValueError("Vector query must be a non-empty list")
+            raise ValueError("Vector query must be a non-empty list")
         if isinstance(sample[0], float):
             # val is list of list of floats
             return val

python/python/lancedb/remote/table.py

@@ -4,7 +4,7 @@
 from datetime import timedelta
 import logging
 from functools import cached_property
-from typing import Dict, Iterable, List, Optional, Union, Literal
+from typing import Any, Callable, Dict, Iterable, List, Optional, Union, Literal
 import warnings
 
 from lancedb._lancedb import (
@@ -35,6 +35,7 @@ import pyarrow as pa
 from lancedb.common import DATA, VEC, VECTOR_COLUMN_NAME
 from lancedb.merge import LanceMergeInsertBuilder
 from lancedb.embeddings import EmbeddingFunctionRegistry
+from lancedb.table import _normalize_progress
 
 from ..query import LanceVectorQueryBuilder, LanceQueryBuilder, LanceTakeQueryBuilder
 from ..table import AsyncTable, IndexStatistics, Query, Table, Tags
@@ -308,6 +309,7 @@ class RemoteTable(Table):
         mode: str = "append",
         on_bad_vectors: str = "error",
         fill_value: float = 0.0,
+        progress: Optional[Union[bool, Callable, Any]] = None,
     ) -> AddResult:
         """Add more data to the [Table](Table). It has the same API signature as
         the OSS version.
@@ -330,17 +332,29 @@ class RemoteTable(Table):
             One of "error", "drop", "fill".
         fill_value: float, default 0.
             The value to use when filling vectors. Only used if on_bad_vectors="fill".
+        progress: bool, callable, or tqdm-like, optional
+            A callback or tqdm-compatible progress bar. See
+            :meth:`Table.add` for details.
 
         Returns
         -------
         AddResult
             An object containing the new version number of the table after adding data.
         """
-        return LOOP.run(
+        progress, owns = _normalize_progress(progress)
-            self._table.add(
+        try:
-                data, mode=mode, on_bad_vectors=on_bad_vectors, fill_value=fill_value
+            return LOOP.run(
+                self._table.add(
+                    data,
+                    mode=mode,
+                    on_bad_vectors=on_bad_vectors,
+                    fill_value=fill_value,
+                    progress=progress,
+                )
             )
-        )
+        finally:
+            if owns:
+                progress.close()
 
     def search(
         self,

python/python/lancedb/table.py

@@ -14,6 +14,7 @@ from functools import cached_property
 from typing import (
     TYPE_CHECKING,
     Any,
+    Callable,
     Dict,
     Iterable,
     List,
@@ -277,7 +278,7 @@ def _sanitize_data(
 
     if metadata:
         new_metadata = target_schema.metadata or {}
-        new_metadata = new_metadata.update(metadata)
+        new_metadata.update(metadata)
         target_schema = target_schema.with_metadata(new_metadata)
 
     _validate_schema(target_schema)
@@ -556,6 +557,21 @@ def _table_uri(base: str, table_name: str) -> str:
     return join_uri(base, f"{table_name}.lance")
 
 
+def _normalize_progress(progress):
+    """Normalize a ``progress`` parameter for :meth:`Table.add`.
+
+    Returns ``(progress_obj, owns)`` where *owns* is True when we created a
+    tqdm bar that the caller must close.
+    """
+    if progress is True:
+        from tqdm.auto import tqdm
+
+        return tqdm(unit=" rows"), True
+    if progress is False or progress is None:
+        return None, False
+    return progress, False
+
+
 class Table(ABC):
     """
     A Table is a collection of Records in a LanceDB Database.
@@ -974,6 +990,7 @@ class Table(ABC):
         mode: AddMode = "append",
         on_bad_vectors: OnBadVectorsType = "error",
         fill_value: float = 0.0,
+        progress: Optional[Union[bool, Callable, Any]] = None,
     ) -> AddResult:
         """Add more data to the [Table](Table).
 
@@ -995,6 +1012,29 @@ class Table(ABC):
             One of "error", "drop", "fill".
         fill_value: float, default 0.
             The value to use when filling vectors. Only used if on_bad_vectors="fill".
+        progress: bool, callable, or tqdm-like, optional
+            Progress reporting during the add operation. Can be:
+
+            - ``True`` to automatically create and display a tqdm progress
+              bar (requires ``tqdm`` to be installed)::
+
+                table.add(data, progress=True)
+
+            - A **callable** that receives a dict with keys ``output_rows``,
+              ``output_bytes``, ``total_rows``, ``elapsed_seconds``,
+              ``active_tasks``, ``total_tasks``, and ``done``::
+
+                def on_progress(p):
+                    print(f"{p['output_rows']}/{p['total_rows']} rows, "
+                          f"{p['active_tasks']}/{p['total_tasks']} workers")
+                table.add(data, progress=on_progress)
+
+            - A **tqdm-compatible** progress bar whose ``total`` and
+              ``update()`` will be called automatically. The postfix shows
+              write throughput (MB/s) and active worker count::
+
+                with tqdm() as pbar:
+                    table.add(data, progress=pbar)
 
         Returns
         -------
@@ -2492,6 +2532,7 @@ class LanceTable(Table):
         mode: AddMode = "append",
         on_bad_vectors: OnBadVectorsType = "error",
         fill_value: float = 0.0,
+        progress: Optional[Union[bool, Callable, Any]] = None,
     ) -> AddResult:
         """Add data to the table.
         If vector columns are missing and the table
@@ -2510,17 +2551,29 @@ class LanceTable(Table):
             One of "error", "drop", "fill", "null".
         fill_value: float, default 0.
             The value to use when filling vectors. Only used if on_bad_vectors="fill".
+        progress: bool, callable, or tqdm-like, optional
+            A callback or tqdm-compatible progress bar. See
+            :meth:`Table.add` for details.
 
         Returns
         -------
         int
             The number of vectors in the table.
         """
-        return LOOP.run(
+        progress, owns = _normalize_progress(progress)
-            self._table.add(
+        try:
-                data, mode=mode, on_bad_vectors=on_bad_vectors, fill_value=fill_value
+            return LOOP.run(
+                self._table.add(
+                    data,
+                    mode=mode,
+                    on_bad_vectors=on_bad_vectors,
+                    fill_value=fill_value,
+                    progress=progress,
+                )
             )
-        )
+        finally:
+            if owns:
+                progress.close()
 
     def merge(
         self,
@@ -3769,6 +3822,7 @@ class AsyncTable:
         mode: Optional[Literal["append", "overwrite"]] = "append",
         on_bad_vectors: Optional[OnBadVectorsType] = None,
         fill_value: Optional[float] = None,
+        progress: Optional[Union[bool, Callable, Any]] = None,
     ) -> AddResult:
         """Add more data to the [Table](Table).
 
@@ -3790,6 +3844,9 @@ class AsyncTable:
             One of "error", "drop", "fill", "null".
         fill_value: float, default 0.
             The value to use when filling vectors. Only used if on_bad_vectors="fill".
+        progress: callable or tqdm-like, optional
+            A callback or tqdm-compatible progress bar. See
+            :meth:`Table.add` for details.
 
         """
         schema = await self.schema()
@@ -3800,7 +3857,13 @@ class AsyncTable:
 
         # _santitize_data is an old code path, but we will use it until the
         # new code path is ready.
-        if on_bad_vectors != "error" or (
+        if mode == "overwrite":
+            # For overwrite, apply the same preprocessing as create_table
+            # so vector columns are inferred as FixedSizeList.
+            data, _ = sanitize_create_table(
+                data, None, on_bad_vectors=on_bad_vectors, fill_value=fill_value
+            )
+        elif on_bad_vectors != "error" or (
             schema.metadata is not None and b"embedding_functions" in schema.metadata
         ):
             data = _sanitize_data(
@@ -3813,8 +3876,9 @@ class AsyncTable:
             )
         _register_optional_converters()
         data = to_scannable(data)
+        progress, owns = _normalize_progress(progress)
         try:
-            return await self._inner.add(data, mode or "append")
+            return await self._inner.add(data, mode or "append", progress=progress)
         except RuntimeError as e:
             if "Cast error" in str(e):
                 raise ValueError(e)
@@ -3822,6 +3886,9 @@ class AsyncTable:
                 raise ValueError(e)
             else:
                 raise
+        finally:
+            if owns:
+                progress.close()
 
     def merge_insert(self, on: Union[str, Iterable[str]]) -> LanceMergeInsertBuilder:
         """
@@ -4751,7 +4818,16 @@ class IndexStatistics:
     num_indexed_rows: int
     num_unindexed_rows: int
     index_type: Literal[
-        "IVF_PQ", "IVF_HNSW_PQ", "IVF_HNSW_SQ", "FTS", "BTREE", "BITMAP", "LABEL_LIST"
+        "IVF_FLAT",
+        "IVF_SQ",
+        "IVF_PQ",
+        "IVF_RQ",
+        "IVF_HNSW_SQ",
+        "IVF_HNSW_PQ",
+        "FTS",
+        "BTREE",
+        "BITMAP",
+        "LABEL_LIST",
     ]
     distance_type: Optional[Literal["l2", "cosine", "dot"]] = None
     num_indices: Optional[int] = None

python/python/tests/test_embeddings.py

@@ -546,3 +546,24 @@ def test_openai_no_retry_on_401(mock_sleep):
     assert mock_func.call_count == 1
     # Verify that sleep was never called (no retries)
     assert mock_sleep.call_count == 0
+
+
+def test_url_retrieve_downloads_image():
+    """
+    Embedding functions like open-clip, siglip, and jinaai use url_retrieve()
+    to download images from HTTP URLs. For example, open_clip._to_pil() calls:
+
+        PIL_Image.open(io.BytesIO(url_retrieve(image)))
+
+    Verify that url_retrieve() can download an image and open it as PIL Image,
+    matching the real usage pattern in embedding functions.
+    """
+    import io
+
+    Image = pytest.importorskip("PIL.Image")
+    from lancedb.embeddings.utils import url_retrieve
+
+    image_url = "http://farm1.staticflickr.com/53/167798175_7c7845bbbd_z.jpg"
+    image_bytes = url_retrieve(image_url)
+    img = Image.open(io.BytesIO(image_bytes))
+    assert img.size[0] > 0 and img.size[1] > 0

python/python/tests/test_index.py

@@ -3,6 +3,7 @@
 
 from datetime import timedelta
 import random
+from typing import get_args, get_type_hints
 
 import pyarrow as pa
 import pytest
@@ -22,6 +23,7 @@ from lancedb.index import (
     HnswSq,
     FTS,
 )
+from lancedb.table import IndexStatistics
 
 
 @pytest_asyncio.fixture
@@ -283,3 +285,23 @@ async def test_create_index_with_binary_vectors(binary_table: AsyncTable):
     for v in range(256):
         res = await binary_table.query().nearest_to([v] * 128).to_arrow()
         assert res["id"][0].as_py() == v
+
+
+def test_index_statistics_index_type_lists_all_supported_values():
+    expected_index_types = {
+        "IVF_FLAT",
+        "IVF_SQ",
+        "IVF_PQ",
+        "IVF_RQ",
+        "IVF_HNSW_SQ",
+        "IVF_HNSW_PQ",
+        "FTS",
+        "BTREE",
+        "BITMAP",
+        "LABEL_LIST",
+    }
+
+    assert (
+        set(get_args(get_type_hints(IndexStatistics)["index_type"]))
+        == expected_index_types
+    )

python/python/tests/test_namespace.py

@@ -8,6 +8,7 @@ import shutil
 import pytest
 import pyarrow as pa
 import lancedb
+from lance_namespace.errors import NamespaceNotEmptyError, TableNotFoundError
 
 
 class TestNamespaceConnection:
@@ -130,7 +131,7 @@ class TestNamespaceConnection:
         assert len(list(db.table_names(namespace=["test_ns"]))) == 0
 
         # Should not be able to open dropped table
-        with pytest.raises(RuntimeError):
+        with pytest.raises(TableNotFoundError):
             db.open_table("table1", namespace=["test_ns"])
 
     def test_create_table_with_schema(self):
@@ -340,7 +341,7 @@ class TestNamespaceConnection:
         db.create_table("test_table", schema=schema, namespace=["test_namespace"])
 
         # Try to drop namespace with tables - should fail
-        with pytest.raises(RuntimeError, match="is not empty"):
+        with pytest.raises(NamespaceNotEmptyError):
             db.drop_namespace(["test_namespace"])
 
         # Drop table first

python/python/tests/test_query.py

@@ -30,6 +30,7 @@ from lancedb.query import (
     PhraseQuery,
     Query,
     FullTextSearchQuery,
+    ensure_vector_query,
 )
 from lancedb.rerankers.cross_encoder import CrossEncoderReranker
 from lancedb.table import AsyncTable, LanceTable
@@ -1501,6 +1502,18 @@ def test_search_empty_table(mem_db):
     assert results == []
 
 
+def test_ensure_vector_query_empty_list():
+    """Regression: ensure_vector_query used to return instead of raise ValueError."""
+    with pytest.raises(ValueError, match="non-empty"):
+        ensure_vector_query([])
+
+
+def test_ensure_vector_query_nested_empty_list():
+    """Regression: ensure_vector_query used to return instead of raise ValueError."""
+    with pytest.raises(ValueError, match="non-empty"):
+        ensure_vector_query([[]])
+
+
 def test_fast_search(tmp_path):
     db = lancedb.connect(tmp_path)
 

python/python/tests/test_table.py

@@ -527,6 +527,132 @@ async def test_add_async(mem_db_async: AsyncConnection):
     assert await table.count_rows() == 3
 
 
+def test_add_overwrite_infers_vector_schema(mem_db: DBConnection):
+    """Overwrite should infer vector columns the same way create_table does.
+
+    Regression test for https://github.com/lancedb/lancedb/issues/3183
+    """
+    table = mem_db.create_table(
+        "test_overwrite_vec",
+        data=[
+            {"vector": [1.0, 2.0, 3.0, 4.0], "item": "foo"},
+            {"vector": [5.0, 6.0, 7.0, 8.0], "item": "bar"},
+        ],
+    )
+    # create_table infers vector as fixed_size_list<float32, 4>
+    original_type = table.schema.field("vector").type
+    assert pa.types.is_fixed_size_list(original_type)
+
+    # overwrite with plain Python lists (PyArrow infers list<double>)
+    table.add(
+        [
+            {"vector": [10.0, 20.0, 30.0, 40.0], "item": "baz"},
+        ],
+        mode="overwrite",
+    )
+    # overwrite should infer vector column the same way as create_table
+    new_type = table.schema.field("vector").type
+    assert pa.types.is_fixed_size_list(new_type), (
+        f"Expected fixed_size_list after overwrite, got {new_type}"
+    )
+
+
+def test_add_progress_callback(mem_db: DBConnection):
+    table = mem_db.create_table(
+        "test",
+        data=[{"id": 1}, {"id": 2}],
+    )
+
+    updates = []
+    table.add([{"id": 3}, {"id": 4}], progress=lambda p: updates.append(dict(p)))
+
+    assert len(table) == 4
+    # The done callback always fires, so we should always get at least one.
+    assert len(updates) >= 1, "expected at least one progress callback"
+    for p in updates:
+        assert "output_rows" in p
+        assert "output_bytes" in p
+        assert "total_rows" in p
+        assert "elapsed_seconds" in p
+        assert "active_tasks" in p
+        assert "total_tasks" in p
+        assert "done" in p
+    # The last callback should have done=True.
+    assert updates[-1]["done"] is True
+
+
+def test_add_progress_tqdm_like(mem_db: DBConnection):
+    """Test that a tqdm-like object gets total set and update() called."""
+
+    class FakeBar:
+        def __init__(self):
+            self.total = None
+            self.n = 0
+            self.postfix = None
+
+        def update(self, n):
+            self.n += n
+
+        def set_postfix_str(self, s):
+            self.postfix = s
+
+        def refresh(self):
+            pass
+
+    table = mem_db.create_table(
+        "test",
+        data=[{"id": 1}, {"id": 2}],
+    )
+
+    bar = FakeBar()
+    table.add([{"id": 3}, {"id": 4}], progress=bar)
+
+    assert len(table) == 4
+    # Postfix should contain throughput and worker count
+    if bar.postfix is not None:
+        assert "MB/s" in bar.postfix
+        assert "workers" in bar.postfix
+
+
+def test_add_progress_bool(mem_db: DBConnection):
+    """Test that progress=True creates and closes a tqdm bar automatically."""
+    table = mem_db.create_table(
+        "test",
+        data=[{"id": 1}, {"id": 2}],
+    )
+
+    table.add([{"id": 3}, {"id": 4}], progress=True)
+    assert len(table) == 4
+
+    # progress=False should be the same as None
+    table.add([{"id": 5}], progress=False)
+    assert len(table) == 5
+
+
+@pytest.mark.asyncio
+async def test_add_progress_callback_async(mem_db_async: AsyncConnection):
+    """Progress callbacks work through the async path too."""
+    table = await mem_db_async.create_table("test", data=[{"id": 1}, {"id": 2}])
+
+    updates = []
+    await table.add([{"id": 3}, {"id": 4}], progress=lambda p: updates.append(dict(p)))
+
+    assert await table.count_rows() == 4
+    assert len(updates) >= 1
+    assert updates[-1]["done"] is True
+
+
+def test_add_progress_callback_error(mem_db: DBConnection):
+    """A failing callback must not prevent the write from succeeding."""
+    table = mem_db.create_table("test", data=[{"id": 1}, {"id": 2}])
+
+    def bad_callback(p):
+        raise RuntimeError("boom")
+
+    table.add([{"id": 3}, {"id": 4}], progress=bad_callback)
+    assert len(table) == 4
+
+
 def test_polars(mem_db: DBConnection):
     data = {
         "vector": [[3.1, 4.1], [5.9, 26.5]],
@@ -2047,3 +2173,33 @@ def test_table_uri(tmp_path):
     db = lancedb.connect(tmp_path)
     table = db.create_table("my_table", data=[{"x": 0}])
     assert table.uri == str(tmp_path / "my_table.lance")
+
+
+def test_sanitize_data_metadata_not_stripped():
+    """Regression test: dict.update() returns None, so assigning its result
+    would silently replace metadata with None, causing with_metadata(None)
+    to strip all schema metadata from the target schema."""
+    from lancedb.table import _sanitize_data
+
+    schema = pa.schema(
+        [pa.field("x", pa.int64())],
+        metadata={b"existing_key": b"existing_value"},
+    )
+    batch = pa.record_batch([pa.array([1, 2, 3])], schema=schema)
+
+    # Use a different field type so the reader and target schemas differ,
+    # forcing _cast_to_target_schema to rebuild the schema with the
+    # target's metadata (instead of taking the fast-path).
+    target_schema = pa.schema(
+        [pa.field("x", pa.int32())],
+        metadata={b"existing_key": b"existing_value"},
+    )
+
+    reader = pa.RecordBatchReader.from_batches(schema, [batch])
+    metadata = {b"new_key": b"new_value"}
+    result = _sanitize_data(reader, target_schema=target_schema, metadata=metadata)
+
+    result_schema = result.schema
+    assert result_schema.metadata is not None
+    assert result_schema.metadata[b"existing_key"] == b"existing_value"
+    assert result_schema.metadata[b"new_key"] == b"new_value"

python/src/table.rs

@@ -19,7 +19,7 @@ use lancedb::table::{
     Table as LanceDbTable,
 };
 use pyo3::{
-    Bound, FromPyObject, PyAny, PyRef, PyResult, Python,
+    Bound, FromPyObject, Py, PyAny, PyRef, PyResult, Python,
     exceptions::{PyKeyError, PyRuntimeError, PyValueError},
     pyclass, pymethods,
     types::{IntoPyDict, PyAnyMethods, PyDict, PyDictMethods},
@@ -299,10 +299,12 @@ impl Table {
         })
     }
 
+    #[pyo3(signature = (data, mode, progress=None))]
     pub fn add<'a>(
         self_: PyRef<'a, Self>,
         data: PyScannable,
         mode: String,
+        progress: Option<Py<PyAny>>,
     ) -> PyResult<Bound<'a, PyAny>> {
         let mut op = self_.inner_ref()?.add(data);
         if mode == "append" {
@@ -312,6 +314,81 @@ impl Table {
         } else {
             return Err(PyValueError::new_err(format!("Invalid mode: {}", mode)));
         }
+        if let Some(progress_obj) = progress {
+            let is_callable = Python::attach(|py| progress_obj.bind(py).is_callable());
+            if is_callable {
+                // Callback: call with a dict of progress info.
+                op = op.progress(move |p| {
+                    Python::attach(|py| {
+                        let dict = PyDict::new(py);
+                        if let Err(e) = dict
+                            .set_item("output_rows", p.output_rows())
+                            .and_then(|_| dict.set_item("output_bytes", p.output_bytes()))
+                            .and_then(|_| dict.set_item("total_rows", p.total_rows()))
+                            .and_then(|_| {
+                                dict.set_item("elapsed_seconds", p.elapsed().as_secs_f64())
+                            })
+                            .and_then(|_| dict.set_item("active_tasks", p.active_tasks()))
+                            .and_then(|_| dict.set_item("total_tasks", p.total_tasks()))
+                            .and_then(|_| dict.set_item("done", p.done()))
+                        {
+                            log::warn!("progress dict error: {e}");
+                            return;
+                        }
+                        if let Err(e) = progress_obj.call1(py, (dict,)) {
+                            log::warn!("progress callback error: {e}");
+                        }
+                    });
+                });
+            } else {
+                // tqdm-like: has update() method.
+                let mut last_rows: usize = 0;
+                let mut total_set = false;
+                op = op.progress(move |p| {
+                    let current = p.output_rows();
+                    let prev = last_rows;
+                    last_rows = current;
+                    Python::attach(|py| {
+                        if let Some(total) = p.total_rows()
+                            && !total_set
+                        {
+                            if let Err(e) = progress_obj.setattr(py, "total", total) {
+                                log::warn!("progress setattr error: {e}");
+                            }
+                            total_set = true;
+                        }
+                        let delta = current.saturating_sub(prev);
+                        if delta > 0 {
+                            if let Err(e) = progress_obj.call_method1(py, "update", (delta,)) {
+                                log::warn!("progress update error: {e}");
+                            }
+                            // Show throughput and active workers in tqdm postfix.
+                            let elapsed = p.elapsed().as_secs_f64();
+                            if elapsed > 0.0 {
+                                let mb_per_sec = p.output_bytes() as f64 / elapsed / 1_000_000.0;
+                                let postfix = format!(
+                                    "{:.1} MB/s | {}/{} workers",
+                                    mb_per_sec,
+                                    p.active_tasks(),
+                                    p.total_tasks()
+                                );
+                                if let Err(e) =
+                                    progress_obj.call_method1(py, "set_postfix_str", (postfix,))
+                                {
+                                    log::warn!("progress set_postfix_str error: {e}");
+                                }
+                            }
+                        }
+                        if p.done() {
+                            // Force a final refresh so the bar shows completion.
+                            if let Err(e) = progress_obj.call_method0(py, "refresh") {
+                                log::warn!("progress refresh error: {e}");
+                            }
+                        }
+                    });
+                });
+            }
+        }
 
         future_into_py(self_.py(), async move {
             let result = op.execute().await.infer_error()?;

rust/lancedb/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lancedb"
-version = "0.27.0"
+version = "0.27.2-beta.1"
 edition.workspace = true
 description = "LanceDB: A serverless, low-latency vector database for AI applications"
 license.workspace = true

rust/lancedb/src/connection.rs

@@ -596,11 +596,8 @@ pub struct ConnectBuilder {
 }
 
 #[cfg(feature = "remote")]
-const ENV_VARS_TO_STORAGE_OPTS: [(&str, &str); 3] = [
+const ENV_VARS_TO_STORAGE_OPTS: [(&str, &str); 1] =
-    ("AZURE_STORAGE_ACCOUNT_NAME", "azure_storage_account_name"),
+    [("AZURE_STORAGE_ACCOUNT_NAME", "azure_storage_account_name")];
-    ("AZURE_CLIENT_ID", "azure_client_id"),
-    ("AZURE_TENANT_ID", "azure_tenant_id"),
-];
 
 impl ConnectBuilder {
     /// Create a new [`ConnectOptions`] with the given database URI.

rust/lancedb/src/dataloader/permutation/shuffle.rs

@@ -240,7 +240,7 @@ impl Shuffler {
                     .await?;
                     // Need to read the entire file in a single batch for in-memory shuffling
                     let batch = reader.read_record_batch(0, reader.num_rows()).await?;
-                    let mut rng = rng.lock().unwrap();
+                    let mut rng = rng.lock().unwrap_or_else(|e| e.into_inner());
                     Self::shuffle_batch(&batch, &mut rng, clump_size)
                 }
             })

rust/lancedb/src/io/object_store/io_tracking.rs

@@ -66,13 +66,13 @@ impl IoTrackingStore {
     }
 
     fn record_read(&self, num_bytes: u64) {
-        let mut stats = self.stats.lock().unwrap();
+        let mut stats = self.stats.lock().unwrap_or_else(|e| e.into_inner());
         stats.read_iops += 1;
         stats.read_bytes += num_bytes;
     }
 
     fn record_write(&self, num_bytes: u64) {
-        let mut stats = self.stats.lock().unwrap();
+        let mut stats = self.stats.lock().unwrap_or_else(|e| e.into_inner());
         stats.write_iops += 1;
         stats.write_bytes += num_bytes;
     }
@@ -229,10 +229,63 @@ impl MultipartUpload for IoTrackingMultipartUpload {
 
     fn put_part(&mut self, payload: PutPayload) -> UploadPart {
         {
-            let mut stats = self.stats.lock().unwrap();
+            let mut stats = self.stats.lock().unwrap_or_else(|e| e.into_inner());
             stats.write_iops += 1;
             stats.write_bytes += payload.content_length() as u64;
         }
         self.target.put_part(payload)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Helper: poison a Mutex<IoStats> by panicking while holding the lock.
+    fn poison_stats(stats: &Arc<Mutex<IoStats>>) {
+        let stats_clone = stats.clone();
+        let handle = std::thread::spawn(move || {
+            let _guard = stats_clone.lock().unwrap();
+            panic!("intentional panic to poison stats mutex");
+        });
+        let _ = handle.join();
+        assert!(stats.lock().is_err(), "mutex should be poisoned");
+    }
+
+    #[test]
+    fn test_record_read_recovers_from_poisoned_lock() {
+        let stats = Arc::new(Mutex::new(IoStats::default()));
+        let store = IoTrackingStore {
+            target: Arc::new(object_store::memory::InMemory::new()),
+            stats: stats.clone(),
+        };
+
+        poison_stats(&stats);
+
+        // record_read should not panic
+        store.record_read(1024);
+
+        // Verify the stats were updated despite poisoning
+        let s = stats.lock().unwrap_or_else(|e| e.into_inner());
+        assert_eq!(s.read_iops, 1);
+        assert_eq!(s.read_bytes, 1024);
+    }
+
+    #[test]
+    fn test_record_write_recovers_from_poisoned_lock() {
+        let stats = Arc::new(Mutex::new(IoStats::default()));
+        let store = IoTrackingStore {
+            target: Arc::new(object_store::memory::InMemory::new()),
+            stats: stats.clone(),
+        };
+
+        poison_stats(&stats);
+
+        // record_write should not panic
+        store.record_write(2048);
+
+        let s = stats.lock().unwrap_or_else(|e| e.into_inner());
+        assert_eq!(s.write_iops, 1);
+        assert_eq!(s.write_bytes, 2048);
+    }
+}

rust/lancedb/src/query.rs

@@ -5,7 +5,7 @@ use std::sync::Arc;
 use std::{future::Future, time::Duration};
 
 use arrow::compute::concat_batches;
-use arrow_array::{Array, Float16Array, Float32Array, Float64Array, make_array};
+use arrow_array::{Array, Float16Array, Float32Array, Float64Array, RecordBatch, make_array};
 use arrow_schema::{DataType, SchemaRef};
 use datafusion_expr::Expr;
 use datafusion_physical_plan::ExecutionPlan;
@@ -17,15 +17,17 @@ use lance_datafusion::exec::execute_plan;
 use lance_index::scalar::FullTextSearchQuery;
 use lance_index::scalar::inverted::SCORE_COL;
 use lance_index::vector::DIST_COL;
-use lance_io::stream::RecordBatchStreamAdapter;
 
 use crate::DistanceType;
 use crate::error::{Error, Result};
 use crate::rerankers::rrf::RRFReranker;
 use crate::rerankers::{NormalizeMethod, Reranker, check_reranker_result};
 use crate::table::BaseTable;
-use crate::utils::TimeoutStream;
+use crate::utils::{MaxBatchLengthStream, TimeoutStream};
-use crate::{arrow::SendableRecordBatchStream, table::AnyQuery};
+use crate::{
+    arrow::{SendableRecordBatchStream, SimpleRecordBatchStream},
+    table::AnyQuery,
+};
 
 mod hybrid;
 
@@ -604,6 +606,14 @@ impl Default for QueryExecutionOptions {
     }
 }
 
+impl QueryExecutionOptions {
+    fn without_output_batch_length_limit(&self) -> Self {
+        let mut options = self.clone();
+        options.max_batch_length = 0;
+        options
+    }
+}
+
 /// A trait for a query object that can be executed to get results
 ///
 /// There are various kinds of queries but they all return results
@@ -1180,6 +1190,8 @@ impl VectorQuery {
         &self,
         options: QueryExecutionOptions,
     ) -> Result<SendableRecordBatchStream> {
+        let max_batch_length = options.max_batch_length as usize;
+        let internal_options = options.without_output_batch_length_limit();
         // clone query and specify we want to include row IDs, which can be needed for reranking
         let mut fts_query = Query::new(self.parent.clone());
         fts_query.request = self.request.base.clone();
@@ -1189,8 +1201,8 @@ impl VectorQuery {
 
         vector_query.request.base.full_text_search = None;
         let (fts_results, vec_results) = try_join!(
-            fts_query.execute_with_options(options.clone()),
+            fts_query.execute_with_options(internal_options.clone()),
-            vector_query.inner_execute_with_options(options)
+            vector_query.inner_execute_with_options(internal_options)
         )?;
 
         let (fts_results, vec_results) = try_join!(
@@ -1245,9 +1257,7 @@ impl VectorQuery {
             results = results.drop_column(ROW_ID)?;
         }
 
-        Ok(SendableRecordBatchStream::from(
+        Ok(single_batch_stream(results, max_batch_length))
-            RecordBatchStreamAdapter::new(results.schema(), stream::iter([Ok(results)])),
-        ))
     }
 
     async fn inner_execute_with_options(
@@ -1256,6 +1266,7 @@ impl VectorQuery {
     ) -> Result<SendableRecordBatchStream> {
         let plan = self.create_plan(options.clone()).await?;
         let inner = execute_plan(plan, Default::default())?;
+        let inner = MaxBatchLengthStream::new_boxed(inner, options.max_batch_length as usize);
         let inner = if let Some(timeout) = options.timeout {
             TimeoutStream::new_boxed(inner, timeout)
         } else {
@@ -1265,6 +1276,25 @@ impl VectorQuery {
     }
 }
 
+fn single_batch_stream(batch: RecordBatch, max_batch_length: usize) -> SendableRecordBatchStream {
+    let schema = batch.schema();
+    if max_batch_length == 0 || batch.num_rows() <= max_batch_length {
+        return Box::pin(SimpleRecordBatchStream::new(
+            stream::iter([Ok(batch)]),
+            schema,
+        ));
+    }
+
+    let mut batches = Vec::with_capacity(batch.num_rows().div_ceil(max_batch_length));
+    let mut offset = 0;
+    while offset < batch.num_rows() {
+        let length = (batch.num_rows() - offset).min(max_batch_length);
+        batches.push(Ok(batch.slice(offset, length)));
+        offset += length;
+    }
+    Box::pin(SimpleRecordBatchStream::new(stream::iter(batches), schema))
+}
+
 impl ExecutableQuery for VectorQuery {
     async fn create_plan(&self, options: QueryExecutionOptions) -> Result<Arc<dyn ExecutionPlan>> {
         let query = AnyQuery::VectorQuery(self.request.clone());
@@ -1753,6 +1783,50 @@ mod tests {
             .unwrap()
     }
 
+    async fn make_large_vector_table(tmp_dir: &tempfile::TempDir, rows: usize) -> Table {
+        let dataset_path = tmp_dir.path().join("large_test.lance");
+        let uri = dataset_path.to_str().unwrap();
+
+        let schema = Arc::new(ArrowSchema::new(vec![
+            ArrowField::new("id", DataType::Utf8, false),
+            ArrowField::new(
+                "vector",
+                DataType::FixedSizeList(
+                    Arc::new(ArrowField::new("item", DataType::Float32, true)),
+                    4,
+                ),
+                false,
+            ),
+        ]));
+
+        let ids = StringArray::from_iter_values((0..rows).map(|i| format!("row-{i}")));
+        let vectors = FixedSizeListArray::from_iter_primitive::<Float32Type, _, _>(
+            (0..rows).map(|i| Some(vec![Some(i as f32), Some(1.0), Some(2.0), Some(3.0)])),
+            4,
+        );
+        let batch =
+            RecordBatch::try_new(schema.clone(), vec![Arc::new(ids), Arc::new(vectors)]).unwrap();
+
+        let conn = connect(uri).execute().await.unwrap();
+        conn.create_table("my_table", vec![batch])
+            .execute()
+            .await
+            .unwrap()
+    }
+
+    async fn assert_stream_batches_at_most(
+        mut results: SendableRecordBatchStream,
+        max_batch_length: usize,
+    ) {
+        let mut saw_batch = false;
+        while let Some(batch) = results.next().await {
+            let batch = batch.unwrap();
+            saw_batch = true;
+            assert!(batch.num_rows() <= max_batch_length);
+        }
+        assert!(saw_batch);
+    }
+
     #[tokio::test]
     async fn test_execute_with_options() {
         let tmp_dir = tempdir().unwrap();
@@ -1772,6 +1846,83 @@ mod tests {
         }
     }
 
+    #[tokio::test]
+    async fn test_vector_query_execute_with_options_respects_max_batch_length() {
+        let tmp_dir = tempdir().unwrap();
+        let table = make_large_vector_table(&tmp_dir, 10_000).await;
+
+        let results = table
+            .query()
+            .nearest_to(vec![0.0, 1.0, 2.0, 3.0])
+            .unwrap()
+            .limit(10_000)
+            .execute_with_options(QueryExecutionOptions {
+                max_batch_length: 100,
+                ..Default::default()
+            })
+            .await
+            .unwrap();
+        assert_stream_batches_at_most(results, 100).await;
+    }
+
+    #[tokio::test]
+    async fn test_hybrid_query_execute_with_options_respects_max_batch_length() {
+        let tmp_dir = tempdir().unwrap();
+        let dataset_path = tmp_dir.path();
+        let conn = connect(dataset_path.to_str().unwrap())
+            .execute()
+            .await
+            .unwrap();
+
+        let dims = 2;
+        let rows = 512;
+        let schema = Arc::new(ArrowSchema::new(vec![
+            ArrowField::new("text", DataType::Utf8, false),
+            ArrowField::new(
+                "vector",
+                DataType::FixedSizeList(
+                    Arc::new(ArrowField::new("item", DataType::Float32, true)),
+                    dims,
+                ),
+                false,
+            ),
+        ]));
+
+        let text = StringArray::from_iter_values((0..rows).map(|_| "match"));
+        let vectors = FixedSizeListArray::from_iter_primitive::<Float32Type, _, _>(
+            (0..rows).map(|i| Some(vec![Some(i as f32), Some(0.0)])),
+            dims,
+        );
+        let record_batch =
+            RecordBatch::try_new(schema.clone(), vec![Arc::new(text), Arc::new(vectors)]).unwrap();
+        let table = conn
+            .create_table("my_table", record_batch)
+            .execute()
+            .await
+            .unwrap();
+
+        table
+            .create_index(&["text"], crate::index::Index::FTS(Default::default()))
+            .replace(true)
+            .execute()
+            .await
+            .unwrap();
+
+        let results = table
+            .query()
+            .full_text_search(FullTextSearchQuery::new("match".to_string()))
+            .limit(rows)
+            .nearest_to(&[0.0, 0.0])
+            .unwrap()
+            .execute_with_options(QueryExecutionOptions {
+                max_batch_length: 100,
+                ..Default::default()
+            })
+            .await
+            .unwrap();
+        assert_stream_batches_at_most(results, 100).await;
+    }
+
     #[tokio::test]
     async fn test_analyze_plan() {
         let tmp_dir = tempdir().unwrap();

rust/lancedb/src/remote/client.rs

@@ -443,23 +443,13 @@ impl<S: HttpSend> RestfulLanceDbClient<S> {
                 })?,
             );
         }
-        // Map azure storage options to x-azure-* headers.
+        if let Some(v) = options.0.get("azure_storage_account_name") {
-        // The option key uses underscores (e.g. "azure_client_id") while the
+            headers.insert(
-        // header uses hyphens (e.g. "x-azure-client-id").
+                HeaderName::from_static("x-azure-storage-account-name"),
-        let azure_opts: [(&str, &str); 3] = [
+                HeaderValue::from_str(v).map_err(|_| Error::InvalidInput {
-            ("azure_storage_account_name", "x-azure-storage-account-name"),
+                    message: format!("non-ascii storage account name '{}' provided", db_name),
-            ("azure_client_id", "x-azure-client-id"),
+                })?,
-            ("azure_tenant_id", "x-azure-tenant-id"),
+            );
-        ];
-        for (opt_key, header_name) in azure_opts {
-            if let Some(v) = options.0.get(opt_key) {
-                headers.insert(
-                    HeaderName::from_static(header_name),
-                    HeaderValue::from_str(v).map_err(|_| Error::InvalidInput {
-                        message: format!("non-ascii value '{}' for option '{}'", v, opt_key),
-                    })?,
-                );
-            }
         }
 
         for (key, value) in &config.extra_headers {
@@ -1082,34 +1072,4 @@ mod tests {
             _ => panic!("Expected Runtime error"),
         }
     }
-
-    #[test]
-    fn test_default_headers_azure_opts() {
-        let mut opts = HashMap::new();
-        opts.insert(
-            "azure_storage_account_name".to_string(),
-            "myaccount".to_string(),
-        );
-        opts.insert("azure_client_id".to_string(), "my-client-id".to_string());
-        opts.insert("azure_tenant_id".to_string(), "my-tenant-id".to_string());
-        let remote_opts = RemoteOptions::new(opts);
-
-        let headers = RestfulLanceDbClient::<Sender>::default_headers(
-            "test-key",
-            "us-east-1",
-            "testdb",
-            false,
-            &remote_opts,
-            None,
-            &ClientConfig::default(),
-        )
-        .unwrap();
-
-        assert_eq!(
-            headers.get("x-azure-storage-account-name").unwrap(),
-            "myaccount"
-        );
-        assert_eq!(headers.get("x-azure-client-id").unwrap(), "my-client-id");
-        assert_eq!(headers.get("x-azure-tenant-id").unwrap(), "my-tenant-id");
-    }
 }

rust/lancedb/src/remote/db.rs

@@ -72,6 +72,10 @@ impl ServerVersion {
     pub fn support_structural_fts(&self) -> bool {
         self.0 >= semver::Version::new(0, 3, 0)
     }
+
+    pub fn support_multipart_write(&self) -> bool {
+        self.0 >= semver::Version::new(0, 4, 0)
+    }
 }
 
 pub const OPT_REMOTE_PREFIX: &str = "remote_database_";
@@ -778,12 +782,7 @@ impl RemoteOptions {
 
 impl From<StorageOptions> for RemoteOptions {
     fn from(options: StorageOptions) -> Self {
-        let supported_opts = vec![
+        let supported_opts = vec!["account_name", "azure_storage_account_name"];
-            "account_name",
-            "azure_storage_account_name",
-            "azure_client_id",
-            "azure_tenant_id",
-        ];
         let mut filtered = HashMap::new();
         for opt in supported_opts {
             if let Some(v) = options.0.get(opt) {

rust/lancedb/src/remote/table/insert.rs

@@ -11,10 +11,14 @@ use arrow_ipc::CompressionType;
 use datafusion_common::{DataFusionError, Result as DataFusionResult};
 use datafusion_execution::{SendableRecordBatchStream, TaskContext};
 use datafusion_physical_expr::EquivalenceProperties;
+use datafusion_physical_plan::metrics::{ExecutionPlanMetricsSet, MetricsSet};
 use datafusion_physical_plan::stream::RecordBatchStreamAdapter;
-use datafusion_physical_plan::{DisplayAs, DisplayFormatType, ExecutionPlan, PlanProperties};
+use datafusion_physical_plan::{
+    DisplayAs, DisplayFormatType, ExecutionPlan, ExecutionPlanProperties, PlanProperties,
+};
 use futures::StreamExt;
 use http::header::CONTENT_TYPE;
+use lance::io::exec::utils::InstrumentedRecordBatchStreamAdapter;
 
 use crate::Error;
 use crate::remote::ARROW_STREAM_CONTENT_TYPE;
@@ -22,13 +26,16 @@ use crate::remote::client::{HttpSend, RestfulLanceDbClient, Sender};
 use crate::remote::table::RemoteTable;
 use crate::table::AddResult;
 use crate::table::datafusion::insert::COUNT_SCHEMA;
+use crate::table::write_progress::WriteProgressTracker;
 
 /// ExecutionPlan for inserting data into a remote LanceDB table.
 ///
-/// This plan:
+/// Streams data as Arrow IPC to `/v1/table/{id}/insert/` endpoint.
-/// 1. Requires single partition (no parallel remote inserts yet)
+///
-/// 2. Streams data as Arrow IPC to `/v1/table/{id}/insert/` endpoint
+/// When `upload_id` is set, inserts are staged as part of a multipart write
-/// 3. Stores AddResult for retrieval after execution
+/// session and the plan supports multiple partitions for parallel uploads.
+/// Without `upload_id`, the plan requires a single partition and commits
+/// immediately.
 #[derive(Debug)]
 pub struct RemoteInsertExec<S: HttpSend = Sender> {
     table_name: String,
@@ -38,21 +45,69 @@ pub struct RemoteInsertExec<S: HttpSend = Sender> {
     overwrite: bool,
     properties: PlanProperties,
     add_result: Arc<Mutex<Option<AddResult>>>,
+    metrics: ExecutionPlanMetricsSet,
+    upload_id: Option<String>,
+    tracker: Option<Arc<WriteProgressTracker>>,
 }
 
 impl<S: HttpSend + 'static> RemoteInsertExec<S> {
-    /// Create a new RemoteInsertExec.
+    /// Create a new single-partition RemoteInsertExec.
     pub fn new(
         table_name: String,
         identifier: String,
         client: RestfulLanceDbClient<S>,
         input: Arc<dyn ExecutionPlan>,
         overwrite: bool,
+        tracker: Option<Arc<WriteProgressTracker>>,
     ) -> Self {
+        Self::new_inner(
+            table_name, identifier, client, input, overwrite, None, tracker,
+        )
+    }
+
+    /// Create a multi-partition RemoteInsertExec for use with multipart writes.
+    ///
+    /// Each partition's insert is staged under the given `upload_id` without
+    /// committing. The caller is responsible for calling the complete (or abort)
+    /// endpoint after all partitions finish.
+    pub fn new_multipart(
+        table_name: String,
+        identifier: String,
+        client: RestfulLanceDbClient<S>,
+        input: Arc<dyn ExecutionPlan>,
+        overwrite: bool,
+        upload_id: String,
+        tracker: Option<Arc<WriteProgressTracker>>,
+    ) -> Self {
+        Self::new_inner(
+            table_name,
+            identifier,
+            client,
+            input,
+            overwrite,
+            Some(upload_id),
+            tracker,
+        )
+    }
+
+    fn new_inner(
+        table_name: String,
+        identifier: String,
+        client: RestfulLanceDbClient<S>,
+        input: Arc<dyn ExecutionPlan>,
+        overwrite: bool,
+        upload_id: Option<String>,
+        tracker: Option<Arc<WriteProgressTracker>>,
+    ) -> Self {
+        let num_partitions = if upload_id.is_some() {
+            input.output_partitioning().partition_count()
+        } else {
+            1
+        };
         let schema = COUNT_SCHEMA.clone();
         let properties = PlanProperties::new(
             EquivalenceProperties::new(schema),
-            datafusion_physical_plan::Partitioning::UnknownPartitioning(1),
+            datafusion_physical_plan::Partitioning::UnknownPartitioning(num_partitions),
             datafusion_physical_plan::execution_plan::EmissionType::Final,
             datafusion_physical_plan::execution_plan::Boundedness::Bounded,
         );
@@ -65,6 +120,9 @@ impl<S: HttpSend + 'static> RemoteInsertExec<S> {
             overwrite,
             properties,
             add_result: Arc::new(Mutex::new(None)),
+            metrics: ExecutionPlanMetricsSet::new(),
+            upload_id,
+            tracker,
         }
     }
 
@@ -72,7 +130,10 @@ impl<S: HttpSend + 'static> RemoteInsertExec<S> {
     // TODO: this will be used when we wire this up to Table::add().
     #[allow(dead_code)]
     pub fn add_result(&self) -> Option<AddResult> {
-        self.add_result.lock().unwrap().clone()
+        self.add_result
+            .lock()
+            .unwrap_or_else(|e| e.into_inner())
+            .clone()
     }
 
     /// Stream the input into an HTTP body as an Arrow IPC stream, capturing any
@@ -83,6 +144,7 @@ impl<S: HttpSend + 'static> RemoteInsertExec<S> {
     fn stream_as_http_body(
         data: SendableRecordBatchStream,
         error_tx: tokio::sync::oneshot::Sender<DataFusionError>,
+        tracker: Option<Arc<WriteProgressTracker>>,
     ) -> DataFusionResult<reqwest::Body> {
         let options = arrow_ipc::writer::IpcWriteOptions::default()
             .try_with_compression(Some(CompressionType::LZ4_FRAME))?;
@@ -94,37 +156,46 @@ impl<S: HttpSend + 'static> RemoteInsertExec<S> {
 
         let stream = futures::stream::try_unfold(
             (data, writer, Some(error_tx), false),
-            move |(mut data, mut writer, error_tx, finished)| async move {
+            move |(mut data, mut writer, error_tx, finished)| {
-                if finished {
+                let tracker = tracker.clone();
-                    return Ok(None);
+                async move {
-                }
+                    if finished {
-                match data.next().await {
+                        return Ok(None);
-                    Some(Ok(batch)) => {
-                        writer
-                            .write(&batch)
-                            .map_err(|e| std::io::Error::other(e.to_string()))?;
-                        let buffer = std::mem::take(writer.get_mut());
-                        Ok(Some((buffer, (data, writer, error_tx, false))))
                     }
-                    Some(Err(e)) => {
+                    match data.next().await {
-                        // Send the original error through the channel before
+                        Some(Ok(batch)) => {
-                        // returning a generic error to reqwest.
+                            writer
-                        if let Some(tx) = error_tx {
+                                .write(&batch)
-                            let _ = tx.send(e);
+                                .map_err(|e| std::io::Error::other(e.to_string()))?;
+                            let buffer = std::mem::take(writer.get_mut());
+                            if let Some(ref t) = tracker {
+                                t.record_bytes(buffer.len());
+                            }
+                            Ok(Some((buffer, (data, writer, error_tx, false))))
                         }
-                        Err(std::io::Error::other(
+                        Some(Err(e)) => {
-                            "input stream error (see error channel)",
+                            // Send the original error through the channel before
-                        ))
+                            // returning a generic error to reqwest.
-                    }
+                            if let Some(tx) = error_tx {
-                    None => {
+                                let _ = tx.send(e);
-                        writer
+                            }
-                            .finish()
+                            Err(std::io::Error::other(
-                            .map_err(|e| std::io::Error::other(e.to_string()))?;
+                                "input stream error (see error channel)",
-                        let buffer = std::mem::take(writer.get_mut());
+                            ))
-                        if buffer.is_empty() {
+                        }
-                            Ok(None)
+                        None => {
-                        } else {
+                            writer
-                            Ok(Some((buffer, (data, writer, None, true))))
+                                .finish()
+                                .map_err(|e| std::io::Error::other(e.to_string()))?;
+                            let buffer = std::mem::take(writer.get_mut());
+                            if buffer.is_empty() {
+                                Ok(None)
+                            } else {
+                                if let Some(ref t) = tracker {
+                                    t.record_bytes(buffer.len());
+                                }
+                                Ok(Some((buffer, (data, writer, None, true))))
+                            }
                         }
                     }
                 }
@@ -174,8 +245,11 @@ impl<S: HttpSend + 'static> ExecutionPlan for RemoteInsertExec<S> {
     }
 
     fn required_input_distribution(&self) -> Vec<datafusion_physical_plan::Distribution> {
-        // Until we have a separate commit endpoint, we need to do all inserts in a single partition
+        if self.upload_id.is_some() {
-        vec![datafusion_physical_plan::Distribution::SinglePartition]
+            vec![datafusion_physical_plan::Distribution::UnspecifiedDistribution]
+        } else {
+            vec![datafusion_physical_plan::Distribution::SinglePartition]
+        }
     }
 
     fn benefits_from_input_partitioning(&self) -> Vec<bool> {
@@ -191,12 +265,14 @@ impl<S: HttpSend + 'static> ExecutionPlan for RemoteInsertExec<S> {
                 "RemoteInsertExec requires exactly one child".to_string(),
             ));
         }
-        Ok(Arc::new(Self::new(
+        Ok(Arc::new(Self::new_inner(
             self.table_name.clone(),
             self.identifier.clone(),
             self.client.clone(),
             children[0].clone(),
             self.overwrite,
+            self.upload_id.clone(),
+            self.tracker.clone(),
         )))
     }
 
@@ -205,18 +281,29 @@ impl<S: HttpSend + 'static> ExecutionPlan for RemoteInsertExec<S> {
         partition: usize,
         context: Arc<TaskContext>,
     ) -> DataFusionResult<SendableRecordBatchStream> {
-        if partition != 0 {
+        if self.upload_id.is_none() && partition != 0 {
             return Err(DataFusionError::Internal(
-                "RemoteInsertExec only supports single partition execution".to_string(),
+                "RemoteInsertExec only supports single partition execution without upload_id"
+                    .to_string(),
             ));
         }
 
-        let input_stream = self.input.execute(0, context)?;
+        let input_stream = self.input.execute(partition, context)?;
+        let input_schema = input_stream.schema();
+        let input_stream: SendableRecordBatchStream =
+            Box::pin(InstrumentedRecordBatchStreamAdapter::new(
+                input_schema,
+                input_stream,
+                partition,
+                &self.metrics,
+            ));
         let client = self.client.clone();
         let identifier = self.identifier.clone();
         let overwrite = self.overwrite;
         let add_result = self.add_result.clone();
         let table_name = self.table_name.clone();
+        let upload_id = self.upload_id.clone();
+        let tracker = self.tracker.clone();
 
         let stream = futures::stream::once(async move {
             let mut request = client
@@ -226,9 +313,12 @@ impl<S: HttpSend + 'static> ExecutionPlan for RemoteInsertExec<S> {
             if overwrite {
                 request = request.query(&[("mode", "overwrite")]);
             }
+            if let Some(ref uid) = upload_id {
+                request = request.query(&[("upload_id", uid.as_str())]);
+            }
 
             let (error_tx, mut error_rx) = tokio::sync::oneshot::channel();
-            let body = Self::stream_as_http_body(input_stream, error_tx)?;
+            let body = Self::stream_as_http_body(input_stream, error_tx, tracker)?;
             let request = request.body(body);
 
             let result: DataFusionResult<(String, _)> = async {
@@ -262,32 +352,43 @@ impl<S: HttpSend + 'static> ExecutionPlan for RemoteInsertExec<S> {
 
             let (request_id, response) = result?;
 
-            let body_text = response.text().await.map_err(|e| {
+            // For multipart writes, the staging response is not the final
-                DataFusionError::External(Box::new(Error::Http {
+            // version. Only parse AddResult for non-multipart inserts.
-                    source: Box::new(e),
+            if upload_id.is_none() {
-                    request_id: request_id.clone(),
+                let body_text = response.text().await.map_err(|e| {
-                    status_code: None,
-                }))
-            })?;
-
-            let parsed_result = if body_text.trim().is_empty() {
-                // Backward compatible with old servers
-                AddResult { version: 0 }
-            } else {
-                serde_json::from_str(&body_text).map_err(|e| {
                     DataFusionError::External(Box::new(Error::Http {
-                        source: format!("Failed to parse add response: {}", e).into(),
+                        source: Box::new(e),
                         request_id: request_id.clone(),
                         status_code: None,
                     }))
-                })?
+                })?;
-            };
+
+                let parsed_result = if body_text.trim().is_empty() {
+                    // Backward compatible with old servers
+                    AddResult { version: 0 }
+                } else {
+                    serde_json::from_str(&body_text).map_err(|e| {
+                        DataFusionError::External(Box::new(Error::Http {
+                            source: format!("Failed to parse add response: {}", e).into(),
+                            request_id: request_id.clone(),
+                            status_code: None,
+                        }))
+                    })?
+                };
 
-            {
                 let mut res_lock = add_result.lock().map_err(|_| {
                     DataFusionError::Execution("Failed to acquire lock for add_result".to_string())
                 })?;
                 *res_lock = Some(parsed_result);
+            } else {
+                // We don't use the body in this case, but we should still consume it.
+                let _ = response.bytes().await.map_err(|e| {
+                    DataFusionError::External(Box::new(Error::Http {
+                        source: Box::new(e),
+                        request_id: request_id.clone(),
+                        status_code: None,
+                    }))
+                })?;
             }
 
             // Return a single batch with count 0 (actual count is tracked in add_result)
@@ -301,6 +402,10 @@ impl<S: HttpSend + 'static> ExecutionPlan for RemoteInsertExec<S> {
             stream,
         )))
     }
+
+    fn metrics(&self) -> Option<MetricsSet> {
+        Some(self.metrics.clone_inner())
+    }
 }
 
 #[cfg(test)]

rust/lancedb/src/table.rs

@@ -74,7 +74,10 @@ pub mod optimize;
 pub mod query;
 pub mod schema_evolution;
 pub mod update;
+pub mod write_progress;
 use crate::index::waiter::wait_for_index;
+#[cfg(feature = "remote")]
+pub(crate) use add_data::PreprocessingOutput;
 pub use add_data::{AddDataBuilder, AddDataMode, AddResult, NaNVectorBehavior};
 pub use chrono::Duration;
 pub use delete::DeleteResult;
@@ -440,6 +443,34 @@ mod test_utils {
                 embedding_registry: Arc::new(MemoryRegistry::new()),
             }
         }
+
+        pub fn new_with_handler_version_and_config<T>(
+            name: impl Into<String>,
+            version: semver::Version,
+            handler: impl Fn(reqwest::Request) -> http::Response<T> + Clone + Send + Sync + 'static,
+            config: crate::remote::ClientConfig,
+        ) -> Self
+        where
+            T: Into<reqwest::Body>,
+        {
+            let inner = Arc::new(
+                crate::remote::table::RemoteTable::new_mock_with_version_and_config(
+                    name.into(),
+                    handler.clone(),
+                    Some(version),
+                    config.clone(),
+                ),
+            );
+            let database = Arc::new(crate::remote::db::RemoteDatabase::new_mock_with_config(
+                handler, config,
+            ));
+            Self {
+                inner,
+                database: Some(database),
+                // Registry is unused.
+                embedding_registry: Arc::new(MemoryRegistry::new()),
+            }
+        }
     }
 }
 
@@ -2198,21 +2229,26 @@ impl BaseTable for NativeTable {
 
         let table_schema = Schema::from(&ds.schema().clone());
 
-        // Peek at the first batch to estimate a good partition count for
+        let num_partitions = if let Some(parallelism) = add.write_parallelism {
-        // write parallelism.
+            parallelism
-        let mut peeked = PeekedScannable::new(add.data);
-        let num_partitions = if let Some(first_batch) = peeked.peek().await {
-            let max_partitions = lance_core::utils::tokio::get_num_compute_intensive_cpus();
-            estimate_write_partitions(
-                first_batch.get_array_memory_size(),
-                first_batch.num_rows(),
-                peeked.num_rows(),
-                max_partitions,
-            )
         } else {
-            1
+            // Peek at the first batch to estimate a good partition count for
+            // write parallelism.
+            let mut peeked = PeekedScannable::new(add.data);
+            let n = if let Some(first_batch) = peeked.peek().await {
+                let max_partitions = lance_core::utils::tokio::get_num_compute_intensive_cpus();
+                estimate_write_partitions(
+                    first_batch.get_array_memory_size(),
+                    first_batch.num_rows(),
+                    peeked.num_rows(),
+                    max_partitions,
+                )
+            } else {
+                1
+            };
+            add.data = Box::new(peeked);
+            n
         };
-        add.data = Box::new(peeked);
 
         let output = add.into_plan(&table_schema, &table_def)?;
 
@@ -2241,13 +2277,21 @@ impl BaseTable for NativeTable {
 
         let insert_exec = Arc::new(InsertExec::new(ds_wrapper.clone(), ds, plan, lance_params));
 
+        let tracker_for_tasks = output.tracker.clone();
+        if let Some(ref t) = tracker_for_tasks {
+            t.set_total_tasks(num_partitions);
+        }
+        let _finish = write_progress::FinishOnDrop(output.tracker);
+
         // Execute all partitions in parallel.
         let task_ctx = Arc::new(TaskContext::default());
         let handles = FuturesUnordered::new();
         for partition in 0..num_partitions {
             let exec = insert_exec.clone();
             let ctx = task_ctx.clone();
+            let tracker = tracker_for_tasks.clone();
             handles.push(tokio::spawn(async move {
+                let _guard = tracker.as_ref().map(|t| t.track_task());
                 let mut stream = exec
                     .execute(partition, ctx)
                     .map_err(|e| -> Error { e.into() })?;

rust/lancedb/src/table/add_data.rs

@@ -13,6 +13,9 @@ use crate::embeddings::EmbeddingRegistry;
 use crate::table::datafusion::cast::cast_to_table_schema;
 use crate::table::datafusion::reject_nan::reject_nan_vectors;
 use crate::table::datafusion::scannable_exec::ScannableExec;
+use crate::table::write_progress::ProgressCallback;
+use crate::table::write_progress::WriteProgress;
+use crate::table::write_progress::WriteProgressTracker;
 use crate::{Error, Result};
 
 use super::{BaseTable, TableDefinition, WriteOptions};
@@ -52,6 +55,8 @@ pub struct AddDataBuilder {
     pub(crate) write_options: WriteOptions,
     pub(crate) on_nan_vectors: NaNVectorBehavior,
     pub(crate) embedding_registry: Option<Arc<dyn EmbeddingRegistry>>,
+    pub(crate) progress_callback: Option<ProgressCallback>,
+    pub(crate) write_parallelism: Option<usize>,
 }
 
 impl std::fmt::Debug for AddDataBuilder {
@@ -77,6 +82,8 @@ impl AddDataBuilder {
             write_options: WriteOptions::default(),
             on_nan_vectors: NaNVectorBehavior::default(),
             embedding_registry,
+            progress_callback: None,
+            write_parallelism: None,
         }
     }
 
@@ -101,7 +108,43 @@ impl AddDataBuilder {
         self
     }
 
+    /// Set a callback to receive progress updates during the add operation.
+    ///
+    /// The callback is invoked once per batch written, and once more with
+    /// [`WriteProgress::done`] set to `true` when the write completes.
+    ///
+    /// ```
+    /// # use lancedb::Table;
+    /// # async fn example(table: &Table) -> Result<(), Box<dyn std::error::Error>> {
+    /// let batch = arrow_array::record_batch!(("id", Int32, [1, 2, 3])).unwrap();
+    /// table.add(batch)
+    ///     .progress(|p| println!("{}/{:?} rows", p.output_rows(), p.total_rows()))
+    ///     .execute()
+    ///     .await?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn progress(mut self, callback: impl FnMut(&WriteProgress) + Send + 'static) -> Self {
+        self.progress_callback = Some(Arc::new(std::sync::Mutex::new(callback)));
+        self
+    }
+
+    /// Set the number of parallel write streams.
+    ///
+    /// By default, the number of streams is estimated from the data size.
+    /// Setting this to `1` disables parallel writes.
+    pub fn write_parallelism(mut self, parallelism: usize) -> Self {
+        self.write_parallelism = Some(parallelism);
+        self
+    }
+
     pub async fn execute(self) -> Result<AddResult> {
+        if self.write_parallelism.map(|p| p == 0).unwrap_or(false) {
+            return Err(Error::InvalidInput {
+                message: "write_parallelism must be greater than 0".to_string(),
+            });
+        }
+
         self.parent.clone().add(self).await
     }
 
@@ -130,8 +173,11 @@ impl AddDataBuilder {
             scannable_with_embeddings(self.data, table_def, self.embedding_registry.as_ref())?;
 
         let rescannable = self.data.rescannable();
+        let tracker = self
+            .progress_callback
+            .map(|cb| Arc::new(WriteProgressTracker::new(cb, self.data.num_rows())));
         let plan: Arc<dyn datafusion_physical_plan::ExecutionPlan> =
-            Arc::new(ScannableExec::new(self.data));
+            Arc::new(ScannableExec::new(self.data, tracker.clone()));
         // Skip casting when overwriting — the input schema replaces the table schema.
         let plan = if overwrite {
             plan
@@ -149,6 +195,7 @@ impl AddDataBuilder {
             rescannable,
             write_options: self.write_options,
             mode: self.mode,
+            tracker,
         })
     }
 }
@@ -161,6 +208,7 @@ pub struct PreprocessingOutput {
     pub rescannable: bool,
     pub write_options: WriteOptions,
     pub mode: AddDataMode,
+    pub tracker: Option<Arc<WriteProgressTracker>>,
 }
 
 /// Check that the input schema is valid for insert.

rust/lancedb/src/table/datafusion/insert.rs

@@ -12,13 +12,16 @@ use datafusion_common::{DataFusionError, Result as DataFusionResult};
 use datafusion_execution::{SendableRecordBatchStream, TaskContext};
 use datafusion_physical_expr::{EquivalenceProperties, Partitioning};
 use datafusion_physical_plan::execution_plan::{Boundedness, EmissionType};
+use datafusion_physical_plan::metrics::{ExecutionPlanMetricsSet, MetricBuilder, MetricsSet};
 use datafusion_physical_plan::stream::RecordBatchStreamAdapter;
 use datafusion_physical_plan::{
     DisplayAs, DisplayFormatType, ExecutionPlan, ExecutionPlanProperties, PlanProperties,
 };
+use futures::TryStreamExt;
 use lance::Dataset;
 use lance::dataset::transaction::{Operation, Transaction};
 use lance::dataset::{CommitBuilder, InsertBuilder, WriteParams};
+use lance::io::exec::utils::InstrumentedRecordBatchStreamAdapter;
 use lance_table::format::Fragment;
 
 use crate::table::dataset::DatasetConsistencyWrapper;
@@ -80,6 +83,7 @@ pub struct InsertExec {
     write_params: WriteParams,
     properties: PlanProperties,
     partial_transactions: Arc<Mutex<Vec<Transaction>>>,
+    metrics: ExecutionPlanMetricsSet,
 }
 
 impl InsertExec {
@@ -105,6 +109,7 @@ impl InsertExec {
             write_params,
             properties,
             partial_transactions: Arc::new(Mutex::new(Vec::with_capacity(num_partitions))),
+            metrics: ExecutionPlanMetricsSet::new(),
         }
     }
 }
@@ -176,6 +181,19 @@ impl ExecutionPlan for InsertExec {
         let total_partitions = self.input.output_partitioning().partition_count();
         let ds_wrapper = self.ds_wrapper.clone();
 
+        let output_bytes = MetricBuilder::new(&self.metrics).output_bytes(partition);
+        let input_schema = input_stream.schema();
+        let input_stream: SendableRecordBatchStream =
+            Box::pin(InstrumentedRecordBatchStreamAdapter::new(
+                input_schema,
+                input_stream.map_ok(move |batch| {
+                    output_bytes.add(batch.get_array_memory_size());
+                    batch
+                }),
+                partition,
+                &self.metrics,
+            ));
+
         let stream = futures::stream::once(async move {
             let transaction = InsertBuilder::new(dataset.clone())
                 .with_params(&write_params)
@@ -186,7 +204,9 @@ impl ExecutionPlan for InsertExec {
 
             let to_commit = {
                 // Don't hold the lock over an await point.
-                let mut txns = partial_transactions.lock().unwrap();
+                let mut txns = partial_transactions
+                    .lock()
+                    .unwrap_or_else(|e| e.into_inner());
                 txns.push(transaction);
                 if txns.len() == total_partitions {
                     Some(std::mem::take(&mut *txns))
@@ -215,6 +235,10 @@ impl ExecutionPlan for InsertExec {
             stream,
         )))
     }
+
+    fn metrics(&self) -> Option<MetricsSet> {
+        Some(self.metrics.clone_inner())
+    }
 }
 
 #[cfg(test)]

rust/lancedb/src/table/datafusion/scannable_exec.rs

@@ -7,17 +7,21 @@ use std::sync::{Arc, Mutex};
 use datafusion_common::{DataFusionError, Result as DFResult, Statistics, stats::Precision};
 use datafusion_execution::{SendableRecordBatchStream, TaskContext};
 use datafusion_physical_expr::{EquivalenceProperties, Partitioning};
+use datafusion_physical_plan::stream::RecordBatchStreamAdapter;
 use datafusion_physical_plan::{
     DisplayAs, DisplayFormatType, ExecutionPlan, PlanProperties, execution_plan::EmissionType,
 };
+use futures::TryStreamExt;
 
+use crate::table::write_progress::WriteProgressTracker;
 use crate::{arrow::SendableRecordBatchStreamExt, data::scannable::Scannable};
 
-pub struct ScannableExec {
+pub(crate) struct ScannableExec {
-    // We don't require Scannable to by Sync, so we wrap it in a Mutex to allow safe concurrent access.
+    // We don't require Scannable to be Sync, so we wrap it in a Mutex to allow safe concurrent access.
     source: Mutex<Box<dyn Scannable>>,
     num_rows: Option<usize>,
     properties: PlanProperties,
+    tracker: Option<Arc<WriteProgressTracker>>,
 }
 
 impl std::fmt::Debug for ScannableExec {
@@ -30,7 +34,7 @@ impl std::fmt::Debug for ScannableExec {
 }
 
 impl ScannableExec {
-    pub fn new(source: Box<dyn Scannable>) -> Self {
+    pub fn new(source: Box<dyn Scannable>, tracker: Option<Arc<WriteProgressTracker>>) -> Self {
         let schema = source.schema();
         let eq_properties = EquivalenceProperties::new(schema);
         let properties = PlanProperties::new(
@@ -46,6 +50,7 @@ impl ScannableExec {
             source,
             num_rows,
             properties,
+            tracker,
         }
     }
 }
@@ -102,7 +107,18 @@ impl ExecutionPlan for ScannableExec {
             Err(poison) => poison.into_inner().scan_as_stream(),
         };
 
-        Ok(stream.into_df_stream())
+        let tracker = self.tracker.clone();
+        let stream = stream.into_df_stream().map_ok(move |batch| {
+            if let Some(ref t) = tracker {
+                t.record_batch(batch.num_rows(), batch.get_array_memory_size());
+            }
+            batch
+        });
+
+        Ok(Box::pin(RecordBatchStreamAdapter::new(
+            self.schema(),
+            stream,
+        )))
     }
 
     fn partition_statistics(&self, _partition: Option<usize>) -> DFResult<Statistics> {

rust/lancedb/src/table/dataset.rs

@@ -82,7 +82,7 @@ impl DatasetConsistencyWrapper {
     /// pinned dataset regardless of consistency mode.
     pub async fn get(&self) -> Result<Arc<Dataset>> {
         {
-            let state = self.state.lock().unwrap();
+            let state = self.state.lock()?;
             if state.pinned_version.is_some() {
                 return Ok(state.dataset.clone());
             }
@@ -101,7 +101,7 @@ impl DatasetConsistencyWrapper {
             }
             ConsistencyMode::Strong => refresh_latest(self.state.clone()).await,
             ConsistencyMode::Lazy => {
-                let state = self.state.lock().unwrap();
+                let state = self.state.lock()?;
                 Ok(state.dataset.clone())
             }
         }
@@ -116,7 +116,7 @@ impl DatasetConsistencyWrapper {
     /// concurrent [`as_time_travel`](Self::as_time_travel) call), the update
     /// is silently ignored — the write already committed to storage.
     pub fn update(&self, dataset: Dataset) {
-        let mut state = self.state.lock().unwrap();
+        let mut state = self.state.lock().unwrap_or_else(|e| e.into_inner());
         if state.pinned_version.is_some() {
             // A concurrent as_time_travel() beat us here. The write succeeded
             // in storage, but since we're now pinned we don't advance the
@@ -139,7 +139,7 @@ impl DatasetConsistencyWrapper {
 
     /// Check that the dataset is in a mutable mode (Latest).
     pub fn ensure_mutable(&self) -> Result<()> {
-        let state = self.state.lock().unwrap();
+        let state = self.state.lock()?;
         if state.pinned_version.is_some() {
             Err(crate::Error::InvalidInput {
                 message: "table cannot be modified when a specific version is checked out"
@@ -152,13 +152,16 @@ impl DatasetConsistencyWrapper {
 
     /// Returns the version, if in time travel mode, or None otherwise.
     pub fn time_travel_version(&self) -> Option<u64> {
-        self.state.lock().unwrap().pinned_version
+        self.state
+            .lock()
+            .unwrap_or_else(|e| e.into_inner())
+            .pinned_version
     }
 
     /// Convert into a wrapper in latest version mode.
     pub async fn as_latest(&self) -> Result<()> {
         let dataset = {
-            let state = self.state.lock().unwrap();
+            let state = self.state.lock()?;
             if state.pinned_version.is_none() {
                 return Ok(());
             }
@@ -168,7 +171,7 @@ impl DatasetConsistencyWrapper {
         let latest_version = dataset.latest_version_id().await?;
         let new_dataset = dataset.checkout_version(latest_version).await?;
 
-        let mut state = self.state.lock().unwrap();
+        let mut state = self.state.lock()?;
         if state.pinned_version.is_some() {
             state.dataset = Arc::new(new_dataset);
             state.pinned_version = None;
@@ -184,7 +187,7 @@ impl DatasetConsistencyWrapper {
         let target_ref = target_version.into();
 
         let (should_checkout, dataset) = {
-            let state = self.state.lock().unwrap();
+            let state = self.state.lock()?;
             let should = match state.pinned_version {
                 None => true,
                 Some(version) => match &target_ref {
@@ -204,7 +207,7 @@ impl DatasetConsistencyWrapper {
         let new_dataset = dataset.checkout_version(target_ref).await?;
         let version_value = new_dataset.version().version;
 
-        let mut state = self.state.lock().unwrap();
+        let mut state = self.state.lock()?;
         state.dataset = Arc::new(new_dataset);
         state.pinned_version = Some(version_value);
         Ok(())
@@ -212,7 +215,7 @@ impl DatasetConsistencyWrapper {
 
     pub async fn reload(&self) -> Result<()> {
         let (dataset, pinned_version) = {
-            let state = self.state.lock().unwrap();
+            let state = self.state.lock()?;
             (state.dataset.clone(), state.pinned_version)
         };
 
@@ -230,7 +233,7 @@ impl DatasetConsistencyWrapper {
 
                 let new_dataset = dataset.checkout_version(version).await?;
 
-                let mut state = self.state.lock().unwrap();
+                let mut state = self.state.lock()?;
                 if state.pinned_version == Some(version) {
                     state.dataset = Arc::new(new_dataset);
                 }
@@ -242,14 +245,14 @@ impl DatasetConsistencyWrapper {
 }
 
 async fn refresh_latest(state: Arc<Mutex<DatasetState>>) -> Result<Arc<Dataset>> {
-    let dataset = { state.lock().unwrap().dataset.clone() };
+    let dataset = { state.lock()?.dataset.clone() };
 
     let mut ds = (*dataset).clone();
     ds.checkout_latest().await?;
     let new_arc = Arc::new(ds);
 
     {
-        let mut state = state.lock().unwrap();
+        let mut state = state.lock()?;
         if state.pinned_version.is_none()
             && new_arc.manifest().version >= state.dataset.manifest().version
         {
@@ -612,4 +615,108 @@ mod tests {
         let s = io_stats.incremental_stats();
         assert_eq!(s.read_iops, 0, "step 5, elapsed={:?}", start.elapsed());
     }
+
+    /// Helper: poison the mutex inside a DatasetConsistencyWrapper.
+    fn poison_state(wrapper: &DatasetConsistencyWrapper) {
+        let state = wrapper.state.clone();
+        let handle = std::thread::spawn(move || {
+            let _guard = state.lock().unwrap();
+            panic!("intentional panic to poison mutex");
+        });
+        let _ = handle.join(); // join collects the panic
+        assert!(wrapper.state.lock().is_err(), "mutex should be poisoned");
+    }
+
+    #[tokio::test]
+    async fn test_get_returns_error_on_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        // get() should return Err, not panic
+        let result = wrapper.get().await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_ensure_mutable_returns_error_on_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        let result = wrapper.ensure_mutable();
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_update_recovers_from_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+        let ds_v2 = append_to_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        // update() returns (), should not panic
+        wrapper.update(ds_v2);
+    }
+
+    #[tokio::test]
+    async fn test_time_travel_version_recovers_from_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        // Should not panic, returns whatever was in the mutex
+        let _version = wrapper.time_travel_version();
+    }
+
+    #[tokio::test]
+    async fn test_as_latest_returns_error_on_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        let result = wrapper.as_latest().await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_as_time_travel_returns_error_on_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        let result = wrapper.as_time_travel(1u64).await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_reload_returns_error_on_poisoned_lock() {
+        let dir = tempfile::tempdir().unwrap();
+        let uri = dir.path().to_str().unwrap();
+        let ds = create_test_dataset(uri).await;
+
+        let wrapper = DatasetConsistencyWrapper::new_latest(ds, None);
+        poison_state(&wrapper);
+
+        let result = wrapper.reload().await;
+        assert!(result.is_err());
+    }
 }

rust/lancedb/src/table/query.rs

@@ -9,7 +9,7 @@ use crate::expr::expr_to_sql_string;
 use crate::query::{
     DEFAULT_TOP_K, QueryExecutionOptions, QueryFilter, QueryRequest, Select, VectorQueryRequest,
 };
-use crate::utils::{TimeoutStream, default_vector_column};
+use crate::utils::{MaxBatchLengthStream, TimeoutStream, default_vector_column};
 use arrow::array::{AsArray, FixedSizeListBuilder, Float32Builder};
 use arrow::datatypes::{Float32Type, UInt8Type};
 use arrow_array::Array;
@@ -66,6 +66,7 @@ async fn execute_generic_query(
 ) -> Result<DatasetRecordBatchStream> {
     let plan = create_plan(table, query, options.clone()).await?;
     let inner = execute_plan(plan, Default::default())?;
+    let inner = MaxBatchLengthStream::new_boxed(inner, options.max_batch_length as usize);
     let inner = if let Some(timeout) = options.timeout {
         TimeoutStream::new_boxed(inner, timeout)
     } else {
@@ -200,7 +201,9 @@ pub async fn create_plan(
         scanner.with_row_id();
     }
 
-    scanner.batch_size(options.max_batch_length as usize);
+    if options.max_batch_length > 0 {
+        scanner.batch_size(options.max_batch_length as usize);
+    }
 
     if query.base.fast_search {
         scanner.fast_search();

rust/lancedb/src/table/write_progress.rs

@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright The LanceDB Authors
+
+//! Progress monitoring for write operations.
+//!
+//! You can add a callback to process progress in [`crate::table::AddDataBuilder::progress`].
+//! [`WriteProgress`] is the struct passed to the callback.
+
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::{Arc, Mutex};
+use std::time::{Duration, Instant};
+
+/// Progress snapshot for a write operation.
+#[derive(Debug, Clone)]
+pub struct WriteProgress {
+    // These are private and only accessible via getters, to make it easy to add
+    // new fields without breaking existing callbacks.
+    elapsed: Duration,
+    output_rows: usize,
+    output_bytes: usize,
+    total_rows: Option<usize>,
+    active_tasks: usize,
+    total_tasks: usize,
+    done: bool,
+}
+
+impl WriteProgress {
+    /// Wall-clock time since monitoring started.
+    pub fn elapsed(&self) -> Duration {
+        self.elapsed
+    }
+
+    /// Number of rows written so far.
+    pub fn output_rows(&self) -> usize {
+        self.output_rows
+    }
+
+    /// Number of bytes written so far.
+    pub fn output_bytes(&self) -> usize {
+        self.output_bytes
+    }
+
+    /// Total rows expected.
+    ///
+    /// Populated when the input source reports a row count (e.g. a
+    /// [`arrow_array::RecordBatch`]).  Always `Some` when [`WriteProgress::done`]
+    /// is `true` — falling back to the actual number of rows written.
+    pub fn total_rows(&self) -> Option<usize> {
+        self.total_rows
+    }
+
+    /// Number of parallel write tasks currently in flight.
+    pub fn active_tasks(&self) -> usize {
+        self.active_tasks
+    }
+
+    /// Total number of parallel write tasks (i.e. the write parallelism).
+    pub fn total_tasks(&self) -> usize {
+        self.total_tasks
+    }
+
+    /// Whether the write operation has completed.
+    ///
+    /// The final callback always has `done = true`.  Callers can use this to
+    /// finalize progress bars or perform cleanup.
+    pub fn done(&self) -> bool {
+        self.done
+    }
+}
+
+/// Callback type for progress updates.
+///
+/// Callbacks are serialized by the tracker and are never invoked reentrantly,
+/// so `FnMut` is safe to use here.
+pub type ProgressCallback = Arc<Mutex<dyn FnMut(&WriteProgress) + Send>>;
+
+/// Tracks progress of a write operation and invokes a [`ProgressCallback`].
+///
+/// Call [`WriteProgressTracker::record_batch`] for each batch written.
+/// Call [`WriteProgressTracker::finish`] once after all data is written.
+///
+/// The callback is never invoked reentrantly: all state updates and callback
+/// invocations are serialized behind a single lock.
+impl std::fmt::Debug for WriteProgressTracker {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("WriteProgressTracker")
+            .field("total_rows", &self.total_rows)
+            .finish()
+    }
+}
+
+pub(crate) struct WriteProgressTracker {
+    rows_and_bytes: std::sync::Mutex<(usize, usize)>,
+    /// Wire bytes tracked separately by the insert layer. When set (> 0),
+    /// this takes precedence over the in-memory bytes from `rows_and_bytes`.
+    wire_bytes: AtomicUsize,
+    active_tasks: Arc<AtomicUsize>,
+    total_tasks: AtomicUsize,
+    start: Instant,
+    /// Known total rows from the input source, if available.
+    total_rows: Option<usize>,
+    callback: ProgressCallback,
+}
+
+impl WriteProgressTracker {
+    pub fn new(callback: ProgressCallback, total_rows: Option<usize>) -> Self {
+        Self {
+            rows_and_bytes: std::sync::Mutex::new((0, 0)),
+            wire_bytes: AtomicUsize::new(0),
+            active_tasks: Arc::new(AtomicUsize::new(0)),
+            total_tasks: AtomicUsize::new(1),
+            start: Instant::now(),
+            total_rows,
+            callback,
+        }
+    }
+
+    /// Set the total number of parallel write tasks (the write parallelism).
+    pub fn set_total_tasks(&self, n: usize) {
+        self.total_tasks.store(n, Ordering::Relaxed);
+    }
+
+    /// Increment the active task count. Returns a guard that decrements on drop.
+    pub fn track_task(&self) -> ActiveTaskGuard {
+        self.active_tasks.fetch_add(1, Ordering::Relaxed);
+        ActiveTaskGuard(self.active_tasks.clone())
+    }
+
+    /// Record a batch of rows passing through the scan node.
+    pub fn record_batch(&self, rows: usize, bytes: usize) {
+        // Lock order: callback first, then rows_and_bytes. This is the only
+        // order used anywhere, so deadlocks cannot occur.
+        let mut cb = self.callback.lock().unwrap_or_else(|e| e.into_inner());
+        let mut guard = self
+            .rows_and_bytes
+            .lock()
+            .unwrap_or_else(|e| e.into_inner());
+        guard.0 += rows;
+        guard.1 += bytes;
+        let progress = self.snapshot(guard.0, guard.1, false);
+        drop(guard);
+        cb(&progress);
+    }
+
+    /// Record wire bytes from the insert layer (e.g. IPC-encoded bytes for
+    /// remote writes). When wire bytes are recorded, they take precedence over
+    /// the in-memory Arrow bytes tracked by [`record_batch`].
+    pub fn record_bytes(&self, bytes: usize) {
+        self.wire_bytes.fetch_add(bytes, Ordering::Relaxed);
+    }
+
+    /// Emit the final progress callback indicating the write is complete.
+    ///
+    /// `total_rows` is always `Some` on the final callback: it uses the known
+    /// total if available, or falls back to the number of rows actually written.
+    pub fn finish(&self) {
+        let mut cb = self.callback.lock().unwrap_or_else(|e| e.into_inner());
+        let guard = self
+            .rows_and_bytes
+            .lock()
+            .unwrap_or_else(|e| e.into_inner());
+        let mut snap = self.snapshot(guard.0, guard.1, true);
+        snap.total_rows = Some(self.total_rows.unwrap_or(guard.0));
+        drop(guard);
+        cb(&snap);
+    }
+
+    fn snapshot(&self, rows: usize, in_memory_bytes: usize, done: bool) -> WriteProgress {
+        let wire = self.wire_bytes.load(Ordering::Relaxed);
+        // Prefer wire bytes (actual I/O size) when the insert layer is
+        // tracking them; fall back to in-memory Arrow size otherwise.
+        // TODO: for local writes, track actual bytes written by Lance
+        // instead of using in-memory Arrow size as a proxy.
+        let output_bytes = if wire > 0 { wire } else { in_memory_bytes };
+        WriteProgress {
+            elapsed: self.start.elapsed(),
+            output_rows: rows,
+            output_bytes,
+            total_rows: self.total_rows,
+            active_tasks: self.active_tasks.load(Ordering::Relaxed),
+            total_tasks: self.total_tasks.load(Ordering::Relaxed),
+            done,
+        }
+    }
+}
+
+/// RAII guard that decrements the active task count when dropped.
+pub(crate) struct ActiveTaskGuard(Arc<AtomicUsize>);
+
+impl Drop for ActiveTaskGuard {
+    fn drop(&mut self) {
+        self.0.fetch_sub(1, Ordering::Relaxed);
+    }
+}
+
+/// RAII guard that calls [`WriteProgressTracker::finish`] on drop.
+///
+/// This ensures the final `done=true` callback fires even if the write
+/// errors or the future is cancelled.
+pub(crate) struct FinishOnDrop(pub Option<Arc<WriteProgressTracker>>);
+
+impl Drop for FinishOnDrop {
+    fn drop(&mut self) {
+        if let Some(t) = self.0.take() {
+            t.finish();
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    use arrow_array::record_batch;
+
+    use crate::connect;
+
+    #[tokio::test]
+    async fn test_progress_monitor_fires_callback() {
+        let db = connect("memory://").execute().await.unwrap();
+
+        let batch = record_batch!(("id", Int32, [1, 2, 3])).unwrap();
+        let table = db
+            .create_table("progress_test", batch)
+            .execute()
+            .await
+            .unwrap();
+
+        let callback_count = Arc::new(AtomicUsize::new(0));
+        let last_rows = Arc::new(AtomicUsize::new(0));
+        let max_active = Arc::new(AtomicUsize::new(0));
+        let last_total_tasks = Arc::new(AtomicUsize::new(0));
+        let cb_count = callback_count.clone();
+        let cb_rows = last_rows.clone();
+        let cb_active = max_active.clone();
+        let cb_total_tasks = last_total_tasks.clone();
+
+        let new_data = record_batch!(("id", Int32, [4, 5, 6])).unwrap();
+        table
+            .add(new_data)
+            .progress(move |p| {
+                cb_count.fetch_add(1, Ordering::SeqCst);
+                cb_rows.store(p.output_rows(), Ordering::SeqCst);
+                cb_active.fetch_max(p.active_tasks(), Ordering::SeqCst);
+                cb_total_tasks.store(p.total_tasks(), Ordering::SeqCst);
+            })
+            .execute()
+            .await
+            .unwrap();
+
+        assert_eq!(table.count_rows(None).await.unwrap(), 6);
+        assert!(callback_count.load(Ordering::SeqCst) >= 1);
+        // Progress tracks the newly inserted rows, not the total table size.
+        assert_eq!(last_rows.load(Ordering::SeqCst), 3);
+        // At least one callback should have seen an active task.
+        assert!(max_active.load(Ordering::SeqCst) >= 1);
+        // total_tasks should reflect the write parallelism.
+        assert!(last_total_tasks.load(Ordering::SeqCst) >= 1);
+    }
+
+    #[tokio::test]
+    async fn test_progress_done_fires_at_end() {
+        let db = connect("memory://").execute().await.unwrap();
+        let batch = record_batch!(("id", Int32, [1, 2, 3])).unwrap();
+        let table = db
+            .create_table("progress_done", batch)
+            .execute()
+            .await
+            .unwrap();
+
+        let seen_done = Arc::new(std::sync::Mutex::new(Vec::<bool>::new()));
+        let seen = seen_done.clone();
+
+        let new_data = record_batch!(("id", Int32, [4, 5, 6])).unwrap();
+        table
+            .add(new_data)
+            .progress(move |p| {
+                seen.lock().unwrap().push(p.done());
+            })
+            .execute()
+            .await
+            .unwrap();
+
+        let done_flags = seen_done.lock().unwrap();
+        assert!(!done_flags.is_empty(), "at least one callback must fire");
+        // Only the last callback should have done=true.
+        let last = *done_flags.last().unwrap();
+        assert!(last, "last callback must have done=true");
+        // All earlier callbacks should have done=false.
+        for &d in done_flags.iter().rev().skip(1) {
+            assert!(!d, "non-final callbacks must have done=false");
+        }
+    }
+
+    #[tokio::test]
+    async fn test_progress_total_rows_known() {
+        let db = connect("memory://").execute().await.unwrap();
+
+        let batch = record_batch!(("id", Int32, [1, 2, 3])).unwrap();
+        let table = db
+            .create_table("total_known", batch)
+            .execute()
+            .await
+            .unwrap();
+
+        let seen_total = Arc::new(std::sync::Mutex::new(Vec::new()));
+        let seen = seen_total.clone();
+
+        // RecordBatch implements Scannable with num_rows() -> Some(3)
+        let new_data = record_batch!(("id", Int32, [4, 5, 6])).unwrap();
+        table
+            .add(new_data)
+            .progress(move |p| {
+                seen.lock().unwrap().push(p.total_rows());
+            })
+            .execute()
+            .await
+            .unwrap();
+
+        let totals = seen_total.lock().unwrap();
+        // All callbacks (including done) should have total_rows = Some(3)
+        assert!(
+            totals.contains(&Some(3)),
+            "expected total_rows=Some(3) in at least one callback, got: {:?}",
+            *totals
+        );
+    }
+
+    #[tokio::test]
+    async fn test_progress_total_rows_unknown() {
+        use arrow_array::RecordBatchIterator;
+
+        let db = connect("memory://").execute().await.unwrap();
+
+        let batch = record_batch!(("id", Int32, [1, 2, 3])).unwrap();
+        let table = db
+            .create_table("total_unknown", batch)
+            .execute()
+            .await
+            .unwrap();
+
+        let seen_total = Arc::new(std::sync::Mutex::new(Vec::new()));
+        let seen = seen_total.clone();
+
+        // RecordBatchReader does not provide num_rows, so total_rows should be
+        // None in intermediate callbacks but always Some on the done callback.
+        let schema = arrow_schema::Schema::new(vec![arrow_schema::Field::new(
+            "id",
+            arrow_schema::DataType::Int32,
+            false,
+        )]);
+        let new_data: Box<dyn arrow_array::RecordBatchReader + Send> =
+            Box::new(RecordBatchIterator::new(
+                vec![Ok(record_batch!(("id", Int32, [4, 5, 6])).unwrap())],
+                Arc::new(schema),
+            ));
+        table
+            .add(new_data)
+            .progress(move |p| {
+                seen.lock().unwrap().push((p.total_rows(), p.done()));
+            })
+            .execute()
+            .await
+            .unwrap();
+
+        let entries = seen_total.lock().unwrap();
+        assert!(!entries.is_empty(), "at least one callback must fire");
+        for (total, done) in entries.iter() {
+            if *done {
+                assert!(
+                    total.is_some(),
+                    "done callback must have total_rows set, got: {:?}",
+                    total
+                );
+            } else {
+                assert_eq!(
+                    *total, None,
+                    "intermediate callback must have total_rows=None, got: {:?}",
+                    total
+                );
+            }
+        }
+    }
+
+    #[test]
+    fn test_record_batch_recovers_from_poisoned_callback_lock() {
+        use super::{ProgressCallback, WriteProgressTracker};
+        use std::sync::Mutex;
+
+        let callback: ProgressCallback = Arc::new(Mutex::new(|_: &super::WriteProgress| {}));
+
+        // Poison the callback mutex
+        let cb_clone = callback.clone();
+        let handle = std::thread::spawn(move || {
+            let _guard = cb_clone.lock().unwrap();
+            panic!("intentional panic to poison callback mutex");
+        });
+        let _ = handle.join();
+        assert!(
+            callback.lock().is_err(),
+            "callback mutex should be poisoned"
+        );
+
+        let tracker = WriteProgressTracker::new(callback, Some(100));
+
+        // record_batch should not panic
+        tracker.record_batch(10, 1024);
+    }
+
+    #[test]
+    fn test_finish_recovers_from_poisoned_callback_lock() {
+        use super::{ProgressCallback, WriteProgressTracker};
+        use std::sync::Mutex;
+
+        let callback: ProgressCallback = Arc::new(Mutex::new(|_: &super::WriteProgress| {}));
+
+        // Poison the callback mutex
+        let cb_clone = callback.clone();
+        let handle = std::thread::spawn(move || {
+            let _guard = cb_clone.lock().unwrap();
+            panic!("intentional panic to poison callback mutex");
+        });
+        let _ = handle.join();
+
+        let tracker = WriteProgressTracker::new(callback, Some(100));
+
+        // finish should not panic
+        tracker.finish();
+    }
+}

rust/lancedb/src/utils/background_cache.rs

@@ -122,7 +122,7 @@ where
     /// This is a cheap synchronous check useful as a fast path before
     /// constructing a fetch closure for [`get()`](Self::get).
     pub fn try_get(&self) -> Option<V> {
-        let cache = self.inner.lock().unwrap();
+        let cache = self.inner.lock().unwrap_or_else(|e| e.into_inner());
         cache.state.fresh_value(self.ttl, self.refresh_window)
     }
 
@@ -138,7 +138,7 @@ where
     {
         // Fast path: check if cache is fresh
         {
-            let cache = self.inner.lock().unwrap();
+            let cache = self.inner.lock().unwrap_or_else(|e| e.into_inner());
             if let Some(value) = cache.state.fresh_value(self.ttl, self.refresh_window) {
                 return Ok(value);
             }
@@ -147,7 +147,7 @@ where
         // Slow path
         let mut fetch = Some(fetch);
         let action = {
-            let mut cache = self.inner.lock().unwrap();
+            let mut cache = self.inner.lock().unwrap_or_else(|e| e.into_inner());
             self.determine_action(&mut cache, &mut fetch)
         };
 
@@ -161,7 +161,7 @@ where
     ///
     /// This avoids a blocking fetch on the first [`get()`](Self::get) call.
     pub fn seed(&self, value: V) {
-        let mut cache = self.inner.lock().unwrap();
+        let mut cache = self.inner.lock().unwrap_or_else(|e| e.into_inner());
         cache.state = State::Current(value, clock::now());
     }
 
@@ -170,7 +170,7 @@ where
     /// Any in-flight background fetch from before this call will not update the
     /// cache (the generation counter prevents stale writes).
     pub fn invalidate(&self) {
-        let mut cache = self.inner.lock().unwrap();
+        let mut cache = self.inner.lock().unwrap_or_else(|e| e.into_inner());
         cache.state = State::Empty;
         cache.generation += 1;
     }
@@ -267,7 +267,7 @@ where
         let fut_for_spawn = shared.clone();
         tokio::spawn(async move {
             let result = fut_for_spawn.await;
-            let mut cache = inner.lock().unwrap();
+            let mut cache = inner.lock().unwrap_or_else(|e| e.into_inner());
             // Only update if no invalidation has happened since we started
             if cache.generation != generation {
                 return;
@@ -590,4 +590,67 @@ mod tests {
         let v = cache.get(ok_fetcher(count.clone(), "fresh")).await.unwrap();
         assert_eq!(v, "fresh");
     }
+
+    /// Helper: poison the inner mutex of a BackgroundCache.
+    fn poison_cache(cache: &BackgroundCache<String, TestError>) {
+        let inner = cache.inner.clone();
+        let handle = std::thread::spawn(move || {
+            let _guard = inner.lock().unwrap();
+            panic!("intentional panic to poison mutex");
+        });
+        let _ = handle.join();
+        assert!(cache.inner.lock().is_err(), "mutex should be poisoned");
+    }
+
+    #[tokio::test]
+    async fn test_try_get_recovers_from_poisoned_lock() {
+        let cache = new_cache();
+        let count = Arc::new(AtomicUsize::new(0));
+
+        // Seed a value first
+        cache.get(ok_fetcher(count.clone(), "hello")).await.unwrap();
+        cache.get(ok_fetcher(count.clone(), "hello")).await.unwrap(); // peek
+
+        poison_cache(&cache);
+
+        // try_get() should not panic — it recovers via unwrap_or_else
+        let result = cache.try_get();
+        // The value may or may not be fresh depending on timing, but it must not panic
+        let _ = result;
+    }
+
+    #[tokio::test]
+    async fn test_get_recovers_from_poisoned_lock() {
+        let cache = new_cache();
+        let count = Arc::new(AtomicUsize::new(0));
+
+        poison_cache(&cache);
+
+        // get() should not panic — it recovers and can still fetch
+        let result = cache.get(ok_fetcher(count.clone(), "recovered")).await;
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), "recovered");
+    }
+
+    #[tokio::test]
+    async fn test_seed_recovers_from_poisoned_lock() {
+        let cache = new_cache();
+        poison_cache(&cache);
+
+        // seed() should not panic
+        cache.seed("seeded".to_string());
+    }
+
+    #[tokio::test]
+    async fn test_invalidate_recovers_from_poisoned_lock() {
+        let cache = new_cache();
+        let count = Arc::new(AtomicUsize::new(0));
+
+        cache.get(ok_fetcher(count.clone(), "hello")).await.unwrap();
+
+        poison_cache(&cache);
+
+        // invalidate() should not panic
+        cache.invalidate();
+    }
 }

rust/lancedb/src/utils/mod.rs

@@ -335,6 +335,85 @@ impl Stream for TimeoutStream {
     }
 }
 
+/// A `Stream` wrapper that slices oversized batches to enforce a maximum batch length.
+pub struct MaxBatchLengthStream {
+    inner: SendableRecordBatchStream,
+    max_batch_length: Option<usize>,
+    buffered_batch: Option<RecordBatch>,
+    buffered_offset: usize,
+}
+
+impl MaxBatchLengthStream {
+    pub fn new(inner: SendableRecordBatchStream, max_batch_length: usize) -> Self {
+        Self {
+            inner,
+            max_batch_length: (max_batch_length > 0).then_some(max_batch_length),
+            buffered_batch: None,
+            buffered_offset: 0,
+        }
+    }
+
+    pub fn new_boxed(
+        inner: SendableRecordBatchStream,
+        max_batch_length: usize,
+    ) -> SendableRecordBatchStream {
+        if max_batch_length == 0 {
+            inner
+        } else {
+            Box::pin(Self::new(inner, max_batch_length))
+        }
+    }
+}
+
+impl RecordBatchStream for MaxBatchLengthStream {
+    fn schema(&self) -> SchemaRef {
+        self.inner.schema()
+    }
+}
+
+impl Stream for MaxBatchLengthStream {
+    type Item = DataFusionResult<RecordBatch>;
+
+    fn poll_next(
+        mut self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        loop {
+            let Some(max_batch_length) = self.max_batch_length else {
+                return Pin::new(&mut self.inner).poll_next(cx);
+            };
+
+            if let Some(batch) = self.buffered_batch.clone() {
+                if self.buffered_offset < batch.num_rows() {
+                    let remaining = batch.num_rows() - self.buffered_offset;
+                    let length = remaining.min(max_batch_length);
+                    let sliced = batch.slice(self.buffered_offset, length);
+                    self.buffered_offset += length;
+                    if self.buffered_offset >= batch.num_rows() {
+                        self.buffered_batch = None;
+                        self.buffered_offset = 0;
+                    }
+                    return std::task::Poll::Ready(Some(Ok(sliced)));
+                }
+
+                self.buffered_batch = None;
+                self.buffered_offset = 0;
+            }
+
+            match Pin::new(&mut self.inner).poll_next(cx) {
+                std::task::Poll::Ready(Some(Ok(batch))) => {
+                    if batch.num_rows() <= max_batch_length {
+                        return std::task::Poll::Ready(Some(Ok(batch)));
+                    }
+                    self.buffered_batch = Some(batch);
+                    self.buffered_offset = 0;
+                }
+                other => return other,
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use arrow_array::Int32Array;
@@ -470,7 +549,7 @@ mod tests {
         assert_eq!(string_to_datatype(string), Some(expected));
     }
 
-    fn sample_batch() -> RecordBatch {
+    fn sample_batch(num_rows: i32) -> RecordBatch {
         let schema = Arc::new(Schema::new(vec![Field::new(
             "col1",
             DataType::Int32,
@@ -478,14 +557,14 @@ mod tests {
         )]));
         RecordBatch::try_new(
             schema.clone(),
-            vec![Arc::new(Int32Array::from(vec![1, 2, 3]))],
+            vec![Arc::new(Int32Array::from_iter_values(0..num_rows))],
         )
         .unwrap()
     }
 
     #[tokio::test]
     async fn test_timeout_stream() {
-        let batch = sample_batch();
+        let batch = sample_batch(3);
         let schema = batch.schema();
         let mock_stream = stream::iter(vec![Ok(batch.clone()), Ok(batch.clone())]);
 
@@ -515,7 +594,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_timeout_stream_zero_duration() {
-        let batch = sample_batch();
+        let batch = sample_batch(3);
         let schema = batch.schema();
         let mock_stream = stream::iter(vec![Ok(batch.clone()), Ok(batch.clone())]);
 
@@ -534,7 +613,7 @@ mod tests {
 
     #[tokio::test]
     async fn test_timeout_stream_completes_normally() {
-        let batch = sample_batch();
+        let batch = sample_batch(3);
         let schema = batch.schema();
         let mock_stream = stream::iter(vec![Ok(batch.clone()), Ok(batch.clone())]);
 
@@ -552,4 +631,35 @@ mod tests {
         // Stream should be empty now
         assert!(timeout_stream.next().await.is_none());
     }
+
+    async fn collect_batch_sizes(
+        stream: SendableRecordBatchStream,
+        max_batch_length: usize,
+    ) -> Vec<usize> {
+        let mut sliced_stream = MaxBatchLengthStream::new(stream, max_batch_length);
+        sliced_stream
+            .by_ref()
+            .map(|batch| batch.unwrap().num_rows())
+            .collect::<Vec<_>>()
+            .await
+    }
+
+    #[tokio::test]
+    async fn test_max_batch_length_stream_behaviors() {
+        let schema = sample_batch(7).schema();
+        let mock_stream = stream::iter(vec![Ok(sample_batch(2)), Ok(sample_batch(7))]);
+
+        let sendable_stream: SendableRecordBatchStream =
+            Box::pin(RecordBatchStreamAdapter::new(schema.clone(), mock_stream));
+        assert_eq!(
+            collect_batch_sizes(sendable_stream, 3).await,
+            vec![2, 3, 3, 1]
+        );
+
+        let sendable_stream: SendableRecordBatchStream = Box::pin(RecordBatchStreamAdapter::new(
+            schema,
+            stream::iter(vec![Ok(sample_batch(2)), Ok(sample_batch(7))]),
+        ));
+        assert_eq!(collect_batch_sizes(sendable_stream, 0).await, vec![2, 7]);
+    }
 }