feat: add mem_wal flag to merge insert for MemWAL write path

Add support for enabling MemWAL (Memory Write-Ahead Log) mode on merge insert operations. This allows streaming writes to route through memory nodes for high-performance buffered writes. Changes: - Add `mem_wal` field to MergeInsertBuilder with validation - Add `x-lancedb-mem-wal-enabled` header for remote requests - Add Python `mem_wal()` method to LanceMergeInsertBuilder - Add validation to ensure only upsert pattern is supported: - when_matched_update_all() without filter - when_not_matched_insert_all() - Throw NotSupported error for native tables - Add mem_wal_enabled to ClientConfig for Python/Node bindings Generated with [Claude Code](https://claude.ai/code) via [Happy](https://happy.engineering) Co-Authored-By: Claude <noreply@anthropic.com> Co-Authored-By: Happy <yesreply@happy.engineering>
fixes for breaking changes
2026-03-29 12:00:39 +00:00 · 2026-03-16 01:04:04 -07:00 · 2026-03-04 15:27:32 -08:00 · 2026-03-04 14:57:17 -08:00
49 changed files with 435 additions and 1302 deletions
--- a/.bumpversion.toml
+++ b/.bumpversion.toml
@@ -1,5 +1,5 @@
 [tool.bumpversion]
-current_version = "0.27.0-beta.5"
+current_version = "0.27.0-beta.3"
 parse = """(?x)
    (?P<major>0|[1-9]\\d*)\\.
    (?P<minor>0|[1-9]\\d*)\\.
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4750,7 +4750,7 @@ dependencies = [

 [[package]]
 name = "lancedb"
-version = "0.27.0-beta.4"
+version = "0.27.0-beta.3"
 dependencies = [
 "ahash",
 "anyhow",
@@ -4832,7 +4832,7 @@ dependencies = [

 [[package]]
 name = "lancedb-nodejs"
-version = "0.27.0-beta.4"
+version = "0.27.0-beta.3"
 dependencies = [
 "arrow-array",
 "arrow-ipc",
@@ -4852,24 +4852,20 @@ dependencies = [

 [[package]]
 name = "lancedb-python"
-version = "0.30.0-beta.4"
+version = "0.30.0-beta.3"
 dependencies = [
 "arrow",
 "async-trait",
- "bytes",
 "env_logger",
 "futures",
 "lance-core",
 "lance-io",
 "lance-namespace",
- "lance-namespace-impls",
 "lancedb",
 "pin-project",
 "pyo3",
 "pyo3-async-runtimes",
 "pyo3-build-config",
- "serde",
- "serde_json",
 "snafu 0.8.9",
 "tokio",
 ]
--- a/docs/mkdocs.yml
+++ b/docs/mkdocs.yml
@@ -52,21 +52,14 @@ plugins:
          options:
            docstring_style: numpy
            heading_level: 3
+            show_source: true
+            show_symbol_type_in_heading: true
            show_signature_annotations: true
            show_root_heading: true
-            show_docstring_examples: true
-            show_docstring_attributes: false
-            show_docstring_other_parameters: true
-            show_symbol_type_heading: true
-            show_labels: false
-            show_if_no_docstring: true
-            show_source: false
            members_order: source
            docstring_section_style: list
            signature_crossrefs: true
            separate_signature: true
-            filters:
-              - "!^_"
          import:
            # for cross references
            - https://arrow.apache.org/docs/objects.inv
@@ -120,7 +113,7 @@ markdown_extensions:
      emoji_index: !!python/name:material.extensions.emoji.twemoji
      emoji_generator: !!python/name:material.extensions.emoji.to_svg
  - markdown.extensions.toc:
-      toc_depth: 4
+      toc_depth: 3
      permalink: true
      permalink_title: Anchor link to this section

--- a/docs/src/java/java.md
+++ b/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-beta.5</version>
+    <version>0.27.0-beta.3</version>
 </dependency>
 ```

--- a/java/README.md
+++ b/java/README.md
@@ -1,4 +1,4 @@
-# LanceDB Java Enterprise Client
+# LanceDB Java SDK

 ## Configuration and Initialization

--- a/java/lancedb-core/pom.xml
+++ b/java/lancedb-core/pom.xml
@@ -8,7 +8,7 @@
    <parent>
      <groupId>com.lancedb</groupId>
      <artifactId>lancedb-parent</artifactId>
-      <version>0.27.0-beta.5</version>
+      <version>0.27.0-beta.3</version>
      <relativePath>../pom.xml</relativePath>
    </parent>

--- a/java/pom.xml
+++ b/java/pom.xml
@@ -6,7 +6,7 @@

    <groupId>com.lancedb</groupId>
    <artifactId>lancedb-parent</artifactId>
-    <version>0.27.0-beta.5</version>
+    <version>0.27.0-beta.3</version>
    <packaging>pom</packaging>
    <name>${project.artifactId}</name>
    <description>LanceDB Java SDK Parent POM</description>
--- a/nodejs/Cargo.toml
+++ b/nodejs/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "lancedb-nodejs"
 edition.workspace = true
-version = "0.27.0-beta.5"
+version = "0.27.0-beta.3"
 license.workspace = true
 description.workspace = true
 repository.workspace = true
--- a/nodejs/test/arrow.test.ts
+++ b/nodejs/test/arrow.test.ts
@@ -63,7 +63,6 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
      tableFromIPC,
      DataType,
      Dictionary,
-      Uint8: ArrowUint8,
      // biome-ignore lint/suspicious/noExplicitAny: <explanation>
    } = <any>arrow;
    type Schema = ApacheArrow["Schema"];
@@ -363,38 +362,6 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
        ).toEqual(new Float64().toString());
      });

-      it("will infer FixedSizeList<Float32> from Float32Array values", async function () {
-        const table = makeArrowTable([
-          { id: "a", vector: new Float32Array([0.1, 0.2, 0.3]) },
-          { id: "b", vector: new Float32Array([0.4, 0.5, 0.6]) },
-        ]);
-
-        expect(DataType.isFixedSizeList(table.getChild("vector")?.type)).toBe(
-          true,
-        );
-        const vectorType = table.getChild("vector")?.type;
-        expect(vectorType.listSize).toBe(3);
-        expect(vectorType.children[0].type.toString()).toEqual(
-          new Float32().toString(),
-        );
-      });
-
-      it("will infer FixedSizeList<Uint8> from Uint8Array values", async function () {
-        const table = makeArrowTable([
-          { id: "a", vector: new Uint8Array([1, 2, 3]) },
-          { id: "b", vector: new Uint8Array([4, 5, 6]) },
-        ]);
-
-        expect(DataType.isFixedSizeList(table.getChild("vector")?.type)).toBe(
-          true,
-        );
-        const vectorType = table.getChild("vector")?.type;
-        expect(vectorType.listSize).toBe(3);
-        expect(vectorType.children[0].type.toString()).toEqual(
-          new ArrowUint8().toString(),
-        );
-      });
-
      it("will use dictionary encoded strings if asked", async function () {
        const table = makeArrowTable([{ str: "hello" }]);
        expect(DataType.isUtf8(table.getChild("str")?.type)).toBe(true);
--- a/nodejs/test/table.test.ts
+++ b/nodejs/test/table.test.ts
@@ -2204,36 +2204,3 @@ describe("when creating an empty table", () => {
    expect((actualSchema.fields[1].type as Float64).precision).toBe(2);
  });
 });
-
-// Ensure we can create float32 arrays without using Arrow
-// by utilizing native JS TypedArray support
-//
-// https://github.com/lancedb/lancedb/issues/3115
-describe("when creating a table with Float32Array vectors", () => {
-  let tmpDir: tmp.DirResult;
-  beforeEach(() => {
-    tmpDir = tmp.dirSync({ unsafeCleanup: true });
-  });
-  afterEach(() => {
-    tmpDir.removeCallback();
-  });
-
-  it("should persist Float32Array as FixedSizeList<Float32> in the LanceDB schema", async () => {
-    const db = await connect(tmpDir.name);
-    const table = await db.createTable("test", [
-      { id: "a", vector: new Float32Array([0.1, 0.2, 0.3]) },
-      { id: "b", vector: new Float32Array([0.4, 0.5, 0.6]) },
-    ]);
-
-    const schema = await table.schema();
-    const vectorField = schema.fields.find((f) => f.name === "vector");
-    expect(vectorField).toBeDefined();
-    expect(vectorField!.type).toBeInstanceOf(FixedSizeList);
-
-    const fsl = vectorField!.type as FixedSizeList;
-    expect(fsl.listSize).toBe(3);
-    expect(fsl.children[0].type.typeId).toBe(Type.Float);
-    // precision: HALF=0, SINGLE=1, DOUBLE=2
-    expect((fsl.children[0].type as Float32).precision).toBe(1);
-  });
-});
--- a/nodejs/lancedb/arrow.ts
+++ b/nodejs/lancedb/arrow.ts
@@ -20,8 +20,6 @@ import {
  Float32,
  Float64,
  Int,
-  Int8,
-  Int16,
  Int32,
  Int64,
  LargeBinary,
@@ -37,8 +35,6 @@ import {
  Timestamp,
  Type,
  Uint8,
-  Uint16,
-  Uint32,
  Utf8,
  Vector,
  makeVector as arrowMakeVector,
@@ -533,8 +529,7 @@ function isObject(value: unknown): value is Record<string, unknown> {
    !(value instanceof Date) &&
    !(value instanceof Set) &&
    !(value instanceof Map) &&
-    !(value instanceof Buffer) &&
-    !ArrayBuffer.isView(value)
+    !(value instanceof Buffer)
  );
 }

@@ -593,13 +588,6 @@ function inferType(
    return new Bool();
  } else if (value instanceof Buffer) {
    return new Binary();
-  } else if (ArrayBuffer.isView(value) && !(value instanceof DataView)) {
-    const info = typedArrayToArrowType(value);
-    if (info !== undefined) {
-      const child = new Field("item", info.elementType, true);
-      return new FixedSizeList(info.length, child);
-    }
-    return undefined;
  } else if (Array.isArray(value)) {
    if (value.length === 0) {
      return undefined; // Without any values we can't infer the type
@@ -758,32 +746,6 @@ function makeListVector(lists: unknown[][]): Vector<unknown> {
  return listBuilder.finish().toVector();
 }

-/**
- * Map a JS TypedArray instance to the corresponding Arrow element DataType
- * and its length. Returns undefined if the value is not a recognized TypedArray.
- */
-function typedArrayToArrowType(
-  value: ArrayBufferView,
-): { elementType: DataType; length: number } | undefined {
-  if (value instanceof Float32Array)
-    return { elementType: new Float32(), length: value.length };
-  if (value instanceof Float64Array)
-    return { elementType: new Float64(), length: value.length };
-  if (value instanceof Uint8Array)
-    return { elementType: new Uint8(), length: value.length };
-  if (value instanceof Uint16Array)
-    return { elementType: new Uint16(), length: value.length };
-  if (value instanceof Uint32Array)
-    return { elementType: new Uint32(), length: value.length };
-  if (value instanceof Int8Array)
-    return { elementType: new Int8(), length: value.length };
-  if (value instanceof Int16Array)
-    return { elementType: new Int16(), length: value.length };
-  if (value instanceof Int32Array)
-    return { elementType: new Int32(), length: value.length };
-  return undefined;
-}
-
 /** Helper function to convert an Array of JS values to an Arrow Vector */
 function makeVector(
  values: unknown[],
@@ -852,16 +814,6 @@ function makeVector(
      "makeVector cannot infer the type if all values are null or undefined",
    );
  }
-  if (ArrayBuffer.isView(sampleValue) && !(sampleValue instanceof DataView)) {
-    const info = typedArrayToArrowType(sampleValue);
-    if (info !== undefined) {
-      const fslType = new FixedSizeList(
-        info.length,
-        new Field("item", info.elementType, true),
-      );
-      return vectorFromArray(values, fslType);
-    }
-  }
  if (Array.isArray(sampleValue)) {
    // Default Arrow inference doesn't handle list types
    return makeListVector(values as unknown[][]);
--- a/nodejs/npm/darwin-arm64/package.json
+++ b/nodejs/npm/darwin-arm64/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-darwin-arm64",
-	"version": "0.27.0-beta.5",
+	"version": "0.27.0-beta.3",
 	"os": ["darwin"],
 	"cpu": ["arm64"],
 	"main": "lancedb.darwin-arm64.node",
--- a/nodejs/npm/linux-arm64-gnu/package.json
+++ b/nodejs/npm/linux-arm64-gnu/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-arm64-gnu",
-	"version": "0.27.0-beta.5",
+	"version": "0.27.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["arm64"],
 	"main": "lancedb.linux-arm64-gnu.node",
--- a/nodejs/npm/linux-arm64-musl/package.json
+++ b/nodejs/npm/linux-arm64-musl/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-arm64-musl",
-	"version": "0.27.0-beta.5",
+	"version": "0.27.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["arm64"],
 	"main": "lancedb.linux-arm64-musl.node",
--- a/nodejs/npm/linux-x64-gnu/package.json
+++ b/nodejs/npm/linux-x64-gnu/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-x64-gnu",
-	"version": "0.27.0-beta.5",
+	"version": "0.27.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["x64"],
 	"main": "lancedb.linux-x64-gnu.node",
--- a/nodejs/npm/linux-x64-musl/package.json
+++ b/nodejs/npm/linux-x64-musl/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-x64-musl",
-	"version": "0.27.0-beta.5",
+	"version": "0.27.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["x64"],
 	"main": "lancedb.linux-x64-musl.node",
--- a/nodejs/npm/win32-arm64-msvc/package.json
+++ b/nodejs/npm/win32-arm64-msvc/package.json
@@ -1,6 +1,6 @@
 {
  "name": "@lancedb/lancedb-win32-arm64-msvc",
-  "version": "0.27.0-beta.5",
+  "version": "0.27.0-beta.3",
  "os": [
    "win32"
  ],
--- a/nodejs/npm/win32-x64-msvc/package.json
+++ b/nodejs/npm/win32-x64-msvc/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-win32-x64-msvc",
-	"version": "0.27.0-beta.5",
+	"version": "0.27.0-beta.3",
 	"os": ["win32"],
 	"cpu": ["x64"],
 	"main": "lancedb.win32-x64-msvc.node",
--- a/nodejs/package-lock.json
+++ b/nodejs/package-lock.json
@@ -1,12 +1,12 @@
 {
  "name": "@lancedb/lancedb",
-  "version": "0.27.0-beta.4",
+  "version": "0.27.0-beta.3",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "@lancedb/lancedb",
-      "version": "0.27.0-beta.4",
+      "version": "0.27.0-beta.3",
      "cpu": [
        "x64",
        "arm64"
--- a/nodejs/package.json
+++ b/nodejs/package.json
@@ -11,7 +11,7 @@
    "ann"
  ],
  "private": false,
-  "version": "0.27.0-beta.5",
+  "version": "0.27.0-beta.3",
  "main": "dist/index.js",
  "exports": {
    ".": "./dist/index.js",
--- a/nodejs/src/remote.rs
+++ b/nodejs/src/remote.rs
@@ -145,6 +145,7 @@ impl From<ClientConfig> for lancedb::remote::ClientConfig {
            id_delimiter: config.id_delimiter,
            tls_config: config.tls_config.map(Into::into),
            header_provider: None, // the header provider is set separately later
+            mem_wal_enabled: None, // mem_wal is set per-operation in merge_insert
        }
    }
 }
--- a/python/.bumpversion.toml
+++ b/python/.bumpversion.toml
@@ -1,5 +1,5 @@
 [tool.bumpversion]
-current_version = "0.30.0-beta.5"
+current_version = "0.30.0-beta.3"
 parse = """(?x)
    (?P<major>0|[1-9]\\d*)\\.
    (?P<minor>0|[1-9]\\d*)\\.
--- a/python/Cargo.toml
+++ b/python/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lancedb-python"
-version = "0.30.0-beta.5"
+version = "0.30.0-beta.3"
 edition.workspace = true
 description = "Python bindings for LanceDB"
 license.workspace = true
@@ -16,11 +16,9 @@ crate-type = ["cdylib"]
 [dependencies]
 arrow = { version = "57.2", features = ["pyarrow"] }
 async-trait = "0.1"
-bytes = "1"
 lancedb = { path = "../rust/lancedb", default-features = false }
 lance-core.workspace = true
 lance-namespace.workspace = true
-lance-namespace-impls.workspace = true
 lance-io.workspace = true
 env_logger.workspace = true
 pyo3 = { version = "0.26", features = ["extension-module", "abi3-py39"] }
@@ -30,8 +28,6 @@ pyo3-async-runtimes = { version = "0.26", features = [
 ] }
 pin-project = "1.1.5"
 futures.workspace = true
-serde = "1"
-serde_json = "1"
 snafu.workspace = true
 tokio = { version = "1.40", features = ["sync"] }

--- a/python/README.md
+++ b/python/README.md
@@ -1,4 +1,4 @@
-# LanceDB Python SDK
+# LanceDB

 A Python library for [LanceDB](https://github.com/lancedb/lancedb).

--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -45,7 +45,7 @@ repository = "https://github.com/lancedb/lancedb"

 [project.optional-dependencies]
 pylance = [
-    "pylance>=4.0.0b7",
+    "pylance>=1.0.0b14",
 ]
 tests = [
    "aiohttp",
@@ -59,9 +59,9 @@ tests = [
    "polars>=0.19, <=1.3.0",
    "tantivy",
    "pyarrow-stubs",
-    "pylance>=4.0.0b7",
+    "pylance>=1.0.0b14,<3.0.0",
    "requests",
-    "datafusion>=52,<53",
+    "datafusion<52",
 ]
 dev = [
    "ruff",
--- a/python/python/lancedb/db.py
+++ b/python/python/lancedb/db.py
@@ -8,7 +8,7 @@ from abc import abstractmethod
 from datetime import timedelta
 from pathlib import Path
 import sys
-from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Literal, Optional, Union
+from typing import TYPE_CHECKING, Dict, Iterable, List, Literal, Optional, Union

 if sys.version_info >= (3, 12):
    from typing import override
@@ -1541,8 +1541,6 @@ class AsyncConnection(object):
        storage_options_provider: Optional["StorageOptionsProvider"] = None,
        index_cache_size: Optional[int] = None,
        location: Optional[str] = None,
-        namespace_client: Optional[Any] = None,
-        managed_versioning: Optional[bool] = None,
    ) -> AsyncTable:
        """Open a Lance Table in the database.

@@ -1575,9 +1573,6 @@ class AsyncConnection(object):
            The explicit location (URI) of the table. If provided, the table will be
            opened from this location instead of deriving it from the database URI
            and table name.
-        managed_versioning: bool, optional
-            Whether managed versioning is enabled for this table. If provided,
-            avoids a redundant describe_table call when namespace_client is set.

        Returns
        -------
@@ -1592,8 +1587,6 @@ class AsyncConnection(object):
            storage_options_provider=storage_options_provider,
            index_cache_size=index_cache_size,
            location=location,
-            namespace_client=namespace_client,
-            managed_versioning=managed_versioning,
        )
        return AsyncTable(table)

--- a/python/python/lancedb/merge.py
+++ b/python/python/lancedb/merge.py
@@ -34,6 +34,7 @@ class LanceMergeInsertBuilder(object):
        self._when_not_matched_by_source_condition = None
        self._timeout = None
        self._use_index = True
+        self._mem_wal = False

    def when_matched_update_all(
        self, *, where: Optional[str] = None
@@ -96,6 +97,47 @@ class LanceMergeInsertBuilder(object):
        self._use_index = use_index
        return self

+    def mem_wal(self, enabled: bool = True) -> LanceMergeInsertBuilder:
+        """
+        Enable MemWAL (Memory Write-Ahead Log) mode for this merge insert operation.
+
+        When enabled, the merge insert will route data through a memory node service
+        that buffers writes before flushing to storage. This is only supported for
+        remote (LanceDB Cloud) tables.
+
+        **Important:** MemWAL only supports the upsert pattern. You must use:
+        - `when_matched_update_all()` (without a filter condition)
+        - `when_not_matched_insert_all()`
+
+        MemWAL does NOT support:
+        - `when_matched_update_all(where=...)` with a filter condition
+        - `when_not_matched_by_source_delete()`
+
+        Parameters
+        ----------
+        enabled: bool
+            Whether to enable MemWAL mode. Defaults to `True`.
+
+        Raises
+        ------
+        NotImplementedError
+            If used on a native (local) table, as MemWAL is only supported for
+            remote tables.
+        ValueError
+            If the merge insert pattern is not supported by MemWAL.
+
+        Examples
+        --------
+        >>> # Correct usage with MemWAL
+        >>> table.merge_insert(["id"]) \\
+        ...     .when_matched_update_all() \\
+        ...     .when_not_matched_insert_all() \\
+        ...     .mem_wal() \\
+        ...     .execute(new_data)
+        """
+        self._mem_wal = enabled
+        return self
+
    def execute(
        self,
        new_data: DATA,
--- a/python/python/lancedb/namespace.py
+++ b/python/python/lancedb/namespace.py
@@ -12,7 +12,7 @@ from __future__ import annotations

 import asyncio
 import sys
-from typing import Any, Dict, Iterable, List, Optional, Union
+from typing import Dict, Iterable, List, Optional, Union

 if sys.version_info >= (3, 12):
    from typing import override
@@ -240,7 +240,7 @@ class LanceNamespaceDBConnection(DBConnection):
        session : Optional[Session]
            A session to use for this connection
        """
-        self._namespace_client = namespace
+        self._ns = namespace
        self.read_consistency_interval = read_consistency_interval
        self.storage_options = storage_options or {}
        self.session = session
@@ -269,7 +269,7 @@ class LanceNamespaceDBConnection(DBConnection):
        if namespace is None:
            namespace = []
        request = ListTablesRequest(id=namespace, page_token=page_token, limit=limit)
-        response = self._namespace_client.list_tables(request)
+        response = self._ns.list_tables(request)
        return response.tables if response.tables else []

    @override
@@ -309,9 +309,7 @@ class LanceNamespaceDBConnection(DBConnection):
            # Try to describe the table first to see if it exists
            try:
                describe_request = DescribeTableRequest(id=table_id)
-                describe_response = self._namespace_client.describe_table(
-                    describe_request
-                )
+                describe_response = self._ns.describe_table(describe_request)
                location = describe_response.location
                namespace_storage_options = describe_response.storage_options
            except Exception:
@@ -325,7 +323,7 @@ class LanceNamespaceDBConnection(DBConnection):
                location=None,
                properties=self.storage_options if self.storage_options else None,
            )
-            declare_response = self._namespace_client.declare_table(declare_request)
+            declare_response = self._ns.declare_table(declare_request)

            if not declare_response.location:
                raise ValueError(
@@ -355,7 +353,7 @@ class LanceNamespaceDBConnection(DBConnection):
        # Only create if namespace returned storage_options (not None)
        if storage_options_provider is None and namespace_storage_options is not None:
            storage_options_provider = LanceNamespaceStorageOptionsProvider(
-                namespace=self._namespace_client,
+                namespace=self._ns,
                table_id=table_id,
            )

@@ -373,7 +371,6 @@ class LanceNamespaceDBConnection(DBConnection):
            storage_options=merged_storage_options,
            storage_options_provider=storage_options_provider,
            location=location,
-            namespace_client=self._namespace_client,
        )

        return tbl
@@ -392,7 +389,7 @@ class LanceNamespaceDBConnection(DBConnection):
            namespace = []
        table_id = namespace + [name]
        request = DescribeTableRequest(id=table_id)
-        response = self._namespace_client.describe_table(request)
+        response = self._ns.describe_table(request)

        # Merge storage options: self.storage_options < user options < namespace options
        merged_storage_options = dict(self.storage_options)
@@ -405,14 +402,10 @@ class LanceNamespaceDBConnection(DBConnection):
        # Only create if namespace returned storage_options (not None)
        if storage_options_provider is None and response.storage_options is not None:
            storage_options_provider = LanceNamespaceStorageOptionsProvider(
-                namespace=self._namespace_client,
+                namespace=self._ns,
                table_id=table_id,
            )

-        # Pass managed_versioning to avoid redundant describe_table call in Rust.
-        # Convert None to False since we already have the answer from describe_table.
-        managed_versioning = response.managed_versioning is True
-
        return self._lance_table_from_uri(
            name,
            response.location,
@@ -420,8 +413,6 @@ class LanceNamespaceDBConnection(DBConnection):
            storage_options=merged_storage_options,
            storage_options_provider=storage_options_provider,
            index_cache_size=index_cache_size,
-            namespace_client=self._namespace_client,
-            managed_versioning=managed_versioning,
        )

    @override
@@ -431,7 +422,7 @@ class LanceNamespaceDBConnection(DBConnection):
            namespace = []
        table_id = namespace + [name]
        request = DropTableRequest(id=table_id)
-        self._namespace_client.drop_table(request)
+        self._ns.drop_table(request)

    @override
    def rename_table(
@@ -493,7 +484,7 @@ class LanceNamespaceDBConnection(DBConnection):
        request = ListNamespacesRequest(
            id=namespace, page_token=page_token, limit=limit
        )
-        response = self._namespace_client.list_namespaces(request)
+        response = self._ns.list_namespaces(request)
        return ListNamespacesResponse(
            namespaces=response.namespaces if response.namespaces else [],
            page_token=response.page_token,
@@ -529,7 +520,7 @@ class LanceNamespaceDBConnection(DBConnection):
            mode=_normalize_create_namespace_mode(mode),
            properties=properties,
        )
-        response = self._namespace_client.create_namespace(request)
+        response = self._ns.create_namespace(request)
        return CreateNamespaceResponse(
            properties=response.properties if hasattr(response, "properties") else None
        )
@@ -564,7 +555,7 @@ class LanceNamespaceDBConnection(DBConnection):
            mode=_normalize_drop_namespace_mode(mode),
            behavior=_normalize_drop_namespace_behavior(behavior),
        )
-        response = self._namespace_client.drop_namespace(request)
+        response = self._ns.drop_namespace(request)
        return DropNamespaceResponse(
            properties=(
                response.properties if hasattr(response, "properties") else None
@@ -590,7 +581,7 @@ class LanceNamespaceDBConnection(DBConnection):
            Response containing the namespace properties.
        """
        request = DescribeNamespaceRequest(id=namespace)
-        response = self._namespace_client.describe_namespace(request)
+        response = self._ns.describe_namespace(request)
        return DescribeNamespaceResponse(
            properties=response.properties if hasattr(response, "properties") else None
        )
@@ -624,7 +615,7 @@ class LanceNamespaceDBConnection(DBConnection):
        if namespace is None:
            namespace = []
        request = ListTablesRequest(id=namespace, page_token=page_token, limit=limit)
-        response = self._namespace_client.list_tables(request)
+        response = self._ns.list_tables(request)
        return ListTablesResponse(
            tables=response.tables if response.tables else [],
            page_token=response.page_token,
@@ -639,8 +630,6 @@ class LanceNamespaceDBConnection(DBConnection):
        storage_options: Optional[Dict[str, str]] = None,
        storage_options_provider: Optional[StorageOptionsProvider] = None,
        index_cache_size: Optional[int] = None,
-        namespace_client: Optional[Any] = None,
-        managed_versioning: Optional[bool] = None,
    ) -> LanceTable:
        # Open a table directly from a URI using the location parameter
        # Note: storage_options should already be merged by the caller
@@ -654,8 +643,6 @@ class LanceNamespaceDBConnection(DBConnection):
        )

        # Open the table using the temporary connection with the location parameter
-        # Pass namespace_client to enable managed versioning support
-        # Pass managed_versioning to avoid redundant describe_table call
        return LanceTable.open(
            temp_conn,
            name,
@@ -664,8 +651,6 @@ class LanceNamespaceDBConnection(DBConnection):
            storage_options_provider=storage_options_provider,
            index_cache_size=index_cache_size,
            location=table_uri,
-            namespace_client=namespace_client,
-            managed_versioning=managed_versioning,
        )


@@ -700,7 +685,7 @@ class AsyncLanceNamespaceDBConnection:
        session : Optional[Session]
            A session to use for this connection
        """
-        self._namespace_client = namespace
+        self._ns = namespace
        self.read_consistency_interval = read_consistency_interval
        self.storage_options = storage_options or {}
        self.session = session
@@ -728,7 +713,7 @@ class AsyncLanceNamespaceDBConnection:
        if namespace is None:
            namespace = []
        request = ListTablesRequest(id=namespace, page_token=page_token, limit=limit)
-        response = self._namespace_client.list_tables(request)
+        response = self._ns.list_tables(request)
        return response.tables if response.tables else []

    async def create_table(
@@ -765,9 +750,7 @@ class AsyncLanceNamespaceDBConnection:
            # Try to describe the table first to see if it exists
            try:
                describe_request = DescribeTableRequest(id=table_id)
-                describe_response = self._namespace_client.describe_table(
-                    describe_request
-                )
+                describe_response = self._ns.describe_table(describe_request)
                location = describe_response.location
                namespace_storage_options = describe_response.storage_options
            except Exception:
@@ -781,7 +764,7 @@ class AsyncLanceNamespaceDBConnection:
                location=None,
                properties=self.storage_options if self.storage_options else None,
            )
-            declare_response = self._namespace_client.declare_table(declare_request)
+            declare_response = self._ns.declare_table(declare_request)

            if not declare_response.location:
                raise ValueError(
@@ -814,7 +797,7 @@ class AsyncLanceNamespaceDBConnection:
                and namespace_storage_options is not None
            ):
                provider = LanceNamespaceStorageOptionsProvider(
-                    namespace=self._namespace_client,
+                    namespace=self._ns,
                    table_id=table_id,
                )
            else:
@@ -834,7 +817,6 @@ class AsyncLanceNamespaceDBConnection:
                storage_options=merged_storage_options,
                storage_options_provider=provider,
                location=location,
-                namespace_client=self._namespace_client,
            )

        lance_table = await asyncio.to_thread(_create_table)
@@ -855,7 +837,7 @@ class AsyncLanceNamespaceDBConnection:
            namespace = []
        table_id = namespace + [name]
        request = DescribeTableRequest(id=table_id)
-        response = self._namespace_client.describe_table(request)
+        response = self._ns.describe_table(request)

        # Merge storage options: self.storage_options < user options < namespace options
        merged_storage_options = dict(self.storage_options)
@@ -867,14 +849,10 @@ class AsyncLanceNamespaceDBConnection:
        # Create a storage options provider if not provided by user
        if storage_options_provider is None and response.storage_options is not None:
            storage_options_provider = LanceNamespaceStorageOptionsProvider(
-                namespace=self._namespace_client,
+                namespace=self._ns,
                table_id=table_id,
            )

-        # Capture managed_versioning from describe response.
-        # Convert None to False since we already have the answer from describe_table.
-        managed_versioning = response.managed_versioning is True
-
        # Open table in a thread
        def _open_table():
            temp_conn = LanceDBConnection(
@@ -892,8 +870,6 @@ class AsyncLanceNamespaceDBConnection:
                storage_options_provider=storage_options_provider,
                index_cache_size=index_cache_size,
                location=response.location,
-                namespace_client=self._namespace_client,
-                managed_versioning=managed_versioning,
            )

        lance_table = await asyncio.to_thread(_open_table)
@@ -905,7 +881,7 @@ class AsyncLanceNamespaceDBConnection:
            namespace = []
        table_id = namespace + [name]
        request = DropTableRequest(id=table_id)
-        self._namespace_client.drop_table(request)
+        self._ns.drop_table(request)

    async def rename_table(
        self,
@@ -967,7 +943,7 @@ class AsyncLanceNamespaceDBConnection:
        request = ListNamespacesRequest(
            id=namespace, page_token=page_token, limit=limit
        )
-        response = self._namespace_client.list_namespaces(request)
+        response = self._ns.list_namespaces(request)
        return ListNamespacesResponse(
            namespaces=response.namespaces if response.namespaces else [],
            page_token=response.page_token,
@@ -1002,7 +978,7 @@ class AsyncLanceNamespaceDBConnection:
            mode=_normalize_create_namespace_mode(mode),
            properties=properties,
        )
-        response = self._namespace_client.create_namespace(request)
+        response = self._ns.create_namespace(request)
        return CreateNamespaceResponse(
            properties=response.properties if hasattr(response, "properties") else None
        )
@@ -1036,7 +1012,7 @@ class AsyncLanceNamespaceDBConnection:
            mode=_normalize_drop_namespace_mode(mode),
            behavior=_normalize_drop_namespace_behavior(behavior),
        )
-        response = self._namespace_client.drop_namespace(request)
+        response = self._ns.drop_namespace(request)
        return DropNamespaceResponse(
            properties=(
                response.properties if hasattr(response, "properties") else None
@@ -1063,7 +1039,7 @@ class AsyncLanceNamespaceDBConnection:
            Response containing the namespace properties.
        """
        request = DescribeNamespaceRequest(id=namespace)
-        response = self._namespace_client.describe_namespace(request)
+        response = self._ns.describe_namespace(request)
        return DescribeNamespaceResponse(
            properties=response.properties if hasattr(response, "properties") else None
        )
@@ -1096,7 +1072,7 @@ class AsyncLanceNamespaceDBConnection:
        if namespace is None:
            namespace = []
        request = ListTablesRequest(id=namespace, page_token=page_token, limit=limit)
-        response = self._namespace_client.list_tables(request)
+        response = self._ns.list_tables(request)
        return ListTablesResponse(
            tables=response.tables if response.tables else [],
            page_token=response.page_token,
--- a/python/python/lancedb/table.py
+++ b/python/python/lancedb/table.py
@@ -1746,8 +1746,6 @@ class LanceTable(Table):
        storage_options_provider: Optional["StorageOptionsProvider"] = None,
        index_cache_size: Optional[int] = None,
        location: Optional[str] = None,
-        namespace_client: Optional[Any] = None,
-        managed_versioning: Optional[bool] = None,
        _async: AsyncTable = None,
    ):
        if namespace is None:
@@ -1755,7 +1753,6 @@ class LanceTable(Table):
        self._conn = connection
        self._namespace = namespace
        self._location = location  # Store location for use in _dataset_path
-        self._namespace_client = namespace_client
        if _async is not None:
            self._table = _async
        else:
@@ -1767,8 +1764,6 @@ class LanceTable(Table):
                    storage_options_provider=storage_options_provider,
                    index_cache_size=index_cache_size,
                    location=location,
-                    namespace_client=namespace_client,
-                    managed_versioning=managed_versioning,
                )
            )

@@ -1811,8 +1806,6 @@ class LanceTable(Table):
        storage_options_provider: Optional["StorageOptionsProvider"] = None,
        index_cache_size: Optional[int] = None,
        location: Optional[str] = None,
-        namespace_client: Optional[Any] = None,
-        managed_versioning: Optional[bool] = None,
    ):
        if namespace is None:
            namespace = []
@@ -1824,8 +1817,6 @@ class LanceTable(Table):
            storage_options_provider=storage_options_provider,
            index_cache_size=index_cache_size,
            location=location,
-            namespace_client=namespace_client,
-            managed_versioning=managed_versioning,
        )

        # check the dataset exists
@@ -1857,16 +1848,6 @@ class LanceTable(Table):
                "Please install with `pip install pylance`."
            )

-        if self._namespace_client is not None:
-            table_id = self._namespace + [self.name]
-            return lance.dataset(
-                version=self.version,
-                storage_options=self._conn.storage_options,
-                namespace=self._namespace_client,
-                table_id=table_id,
-                **kwargs,
-            )
-
        return lance.dataset(
            self._dataset_path,
            version=self.version,
@@ -2732,7 +2713,6 @@ class LanceTable(Table):
        data_storage_version: Optional[str] = None,
        enable_v2_manifest_paths: Optional[bool] = None,
        location: Optional[str] = None,
-        namespace_client: Optional[Any] = None,
    ):
        """
        Create a new table.
@@ -2793,7 +2773,6 @@ class LanceTable(Table):
        self._conn = db
        self._namespace = namespace
        self._location = location
-        self._namespace_client = namespace_client

        if data_storage_version is not None:
            warnings.warn(
@@ -4202,6 +4181,7 @@ class AsyncTable:
                when_not_matched_by_source_condition=merge._when_not_matched_by_source_condition,
                timeout=merge._timeout,
                use_index=merge._use_index,
+                mem_wal=merge._mem_wal,
            ),
        )

--- a/python/python/tests/test_table.py
+++ b/python/python/tests/test_table.py
@@ -326,24 +326,6 @@ def test_add_struct(mem_db: DBConnection):
    table = mem_db.create_table("test2", schema=schema)
    table.add(data)

-    struct_type = pa.struct(
-        [
-            ("b", pa.int64()),
-            ("a", pa.int64()),
-        ]
-    )
-    expected = pa.table(
-        {
-            "s_list": [
-                [
-                    pa.scalar({"b": 1, "a": 2}, type=struct_type),
-                    pa.scalar({"b": 4, "a": None}, type=struct_type),
-                ]
-            ],
-        }
-    )
-    assert table.to_arrow() == expected
-

 def test_add_subschema(mem_db: DBConnection):
    schema = pa.schema(
--- a/python/src/connection.rs
+++ b/python/src/connection.rs
@@ -17,8 +17,7 @@ use pyo3::{
 use pyo3_async_runtimes::tokio::future_into_py;

 use crate::{
-    error::PythonErrorExt, namespace::extract_namespace_arc,
-    storage_options::py_object_to_storage_options_provider, table::Table,
+    error::PythonErrorExt, storage_options::py_object_to_storage_options_provider, table::Table,
 };

 #[pyclass]
@@ -183,8 +182,7 @@ impl Connection {
        })
    }

-    #[allow(clippy::too_many_arguments)]
-    #[pyo3(signature = (name, namespace=vec![], storage_options = None, storage_options_provider=None, index_cache_size = None, location=None, namespace_client=None, managed_versioning=None))]
+    #[pyo3(signature = (name, namespace=vec![], storage_options = None, storage_options_provider=None, index_cache_size = None, location=None))]
    pub fn open_table(
        self_: PyRef<'_, Self>,
        name: String,
@@ -193,13 +191,11 @@ impl Connection {
        storage_options_provider: Option<Py<PyAny>>,
        index_cache_size: Option<u32>,
        location: Option<String>,
-        namespace_client: Option<Py<PyAny>>,
-        managed_versioning: Option<bool>,
    ) -> PyResult<Bound<'_, PyAny>> {
        let inner = self_.get_inner()?.clone();

        let mut builder = inner.open_table(name);
-        builder = builder.namespace(namespace.clone());
+        builder = builder.namespace(namespace);
        if let Some(storage_options) = storage_options {
            builder = builder.storage_options(storage_options);
        }
@@ -213,20 +209,6 @@ impl Connection {
        if let Some(location) = location {
            builder = builder.location(location);
        }
-        // Extract namespace client from Python object if provided
-        let ns_client = if let Some(ns_obj) = namespace_client {
-            let py = self_.py();
-            Some(extract_namespace_arc(py, ns_obj)?)
-        } else {
-            None
-        };
-        if let Some(ns_client) = ns_client {
-            builder = builder.namespace_client(ns_client);
-        }
-        // Pass managed_versioning if provided to avoid redundant describe_table call
-        if let Some(enabled) = managed_versioning {
-            builder = builder.managed_versioning(enabled);
-        }

        future_into_py(self_.py(), async move {
            let table = builder.execute().await.infer_error()?;
@@ -524,6 +506,7 @@ pub struct PyClientConfig {
    id_delimiter: Option<String>,
    tls_config: Option<PyClientTlsConfig>,
    header_provider: Option<Py<PyAny>>,
+    mem_wal_enabled: Option<bool>,
 }

 #[derive(FromPyObject)]
@@ -608,6 +591,7 @@ impl From<PyClientConfig> for lancedb::remote::ClientConfig {
            id_delimiter: value.id_delimiter,
            tls_config: value.tls_config.map(Into::into),
            header_provider,
+            mem_wal_enabled: value.mem_wal_enabled,
        }
    }
 }
--- a/python/src/lib.rs
+++ b/python/src/lib.rs
@@ -23,7 +23,6 @@ pub mod connection;
 pub mod error;
 pub mod header;
 pub mod index;
-pub mod namespace;
 pub mod permutation;
 pub mod query;
 pub mod session;
--- a/python/src/namespace.rs
+++ b/python/src/namespace.rs
@@ -1,696 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-// SPDX-FileCopyrightText: Copyright The LanceDB Authors
-
-//! Namespace utilities for Python bindings
-
-use std::collections::HashMap;
-use std::sync::Arc;
-
-use async_trait::async_trait;
-use bytes::Bytes;
-use lance_namespace::LanceNamespace as LanceNamespaceTrait;
-use lance_namespace::models::*;
-use pyo3::prelude::*;
-use pyo3::types::PyDict;
-
-/// Wrapper that allows any Python object implementing LanceNamespace protocol
-/// to be used as a Rust LanceNamespace.
-///
-/// This is similar to PyLanceNamespace in lance's Python bindings - it wraps a Python
-/// object and calls back into Python when namespace methods are invoked.
-pub struct PyLanceNamespace {
-    py_namespace: Arc<Py<PyAny>>,
-    namespace_id: String,
-}
-
-impl PyLanceNamespace {
-    /// Create a new PyLanceNamespace wrapper around a Python namespace object.
-    pub fn new(_py: Python<'_>, py_namespace: &Bound<'_, PyAny>) -> PyResult<Self> {
-        let namespace_id = py_namespace
-            .call_method0("namespace_id")?
-            .extract::<String>()?;
-
-        Ok(Self {
-            py_namespace: Arc::new(py_namespace.clone().unbind()),
-            namespace_id,
-        })
-    }
-
-    /// Create an Arc<dyn LanceNamespace> from a Python namespace object.
-    pub fn create_arc(
-        py: Python<'_>,
-        py_namespace: &Bound<'_, PyAny>,
-    ) -> PyResult<Arc<dyn LanceNamespaceTrait>> {
-        let wrapper = Self::new(py, py_namespace)?;
-        Ok(Arc::new(wrapper))
-    }
-}
-
-impl std::fmt::Debug for PyLanceNamespace {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "PyLanceNamespace {{ id: {} }}", self.namespace_id)
-    }
-}
-
-/// Get or create the DictWithModelDump class in Python.
-/// This class acts like a dict but also has model_dump() method.
-/// This allows it to work with both:
-/// - depythonize (which expects a dict/Mapping)
-/// - Python code that calls .model_dump() (like DirectoryNamespace wrapper)
-fn get_dict_with_model_dump_class(py: Python<'_>) -> PyResult<Bound<'_, PyAny>> {
-    // Use a module-level cache via __builtins__
-    let builtins = py.import("builtins")?;
-    if builtins.hasattr("_DictWithModelDump")? {
-        return builtins.getattr("_DictWithModelDump");
-    }
-
-    // Create the class using exec
-    let locals = PyDict::new(py);
-    py.run(
-        c"class DictWithModelDump(dict):
-    def model_dump(self):
-        return dict(self)",
-        None,
-        Some(&locals),
-    )?;
-    let class = locals.get_item("DictWithModelDump")?.ok_or_else(|| {
-        pyo3::exceptions::PyRuntimeError::new_err("Failed to create DictWithModelDump class")
-    })?;
-
-    // Cache it
-    builtins.setattr("_DictWithModelDump", &class)?;
-    Ok(class)
-}
-
-/// Helper to call a Python namespace method with JSON serialization.
-/// For methods that take a request and return a response.
-/// Uses DictWithModelDump to pass a dict that also has model_dump() method,
-/// making it compatible with both depythonize and Python wrappers.
-async fn call_py_method<Req, Resp>(
-    py_namespace: Arc<Py<PyAny>>,
-    method_name: &'static str,
-    request: Req,
-) -> lance_core::Result<Resp>
-where
-    Req: serde::Serialize + Send + 'static,
-    Resp: serde::de::DeserializeOwned + Send + 'static,
-{
-    let request_json = serde_json::to_string(&request).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to serialize request for {}: {}",
-            method_name, e
-        ))
-    })?;
-
-    let response_json = tokio::task::spawn_blocking(move || {
-        Python::attach(|py| {
-            let json_module = py.import("json")?;
-            let request_dict = json_module.call_method1("loads", (&request_json,))?;
-
-            // Wrap dict in DictWithModelDump so it works with both depythonize and .model_dump()
-            let dict_class = get_dict_with_model_dump_class(py)?;
-            let request_arg = dict_class.call1((request_dict,))?;
-
-            // Call the Python method
-            let result = py_namespace.call_method1(py, method_name, (request_arg,))?;
-
-            // Convert response to dict, then to JSON
-            // Pydantic models have model_dump() method
-            let result_dict = if result.bind(py).hasattr("model_dump")? {
-                result.call_method0(py, "model_dump")?
-            } else {
-                result
-            };
-            let response_json: String = json_module
-                .call_method1("dumps", (result_dict,))?
-                .extract()?;
-            Ok::<_, PyErr>(response_json)
-        })
-    })
-    .await
-    .map_err(|e| lance_core::Error::io(format!("Task join error for {}: {}", method_name, e)))?
-    .map_err(|e: PyErr| lance_core::Error::io(format!("Python error in {}: {}", method_name, e)))?;
-
-    serde_json::from_str(&response_json).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to deserialize response from {}: {}",
-            method_name, e
-        ))
-    })
-}
-
-/// Helper for methods that return () on success
-async fn call_py_method_unit<Req>(
-    py_namespace: Arc<Py<PyAny>>,
-    method_name: &'static str,
-    request: Req,
-) -> lance_core::Result<()>
-where
-    Req: serde::Serialize + Send + 'static,
-{
-    let request_json = serde_json::to_string(&request).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to serialize request for {}: {}",
-            method_name, e
-        ))
-    })?;
-
-    tokio::task::spawn_blocking(move || {
-        Python::attach(|py| {
-            let json_module = py.import("json")?;
-            let request_dict = json_module.call_method1("loads", (&request_json,))?;
-
-            // Wrap dict in DictWithModelDump
-            let dict_class = get_dict_with_model_dump_class(py)?;
-            let request_arg = dict_class.call1((request_dict,))?;
-
-            // Call the Python method
-            py_namespace.call_method1(py, method_name, (request_arg,))?;
-            Ok::<_, PyErr>(())
-        })
-    })
-    .await
-    .map_err(|e| lance_core::Error::io(format!("Task join error for {}: {}", method_name, e)))?
-    .map_err(|e: PyErr| lance_core::Error::io(format!("Python error in {}: {}", method_name, e)))
-}
-
-/// Helper for methods that return a primitive type
-async fn call_py_method_primitive<Req, Resp>(
-    py_namespace: Arc<Py<PyAny>>,
-    method_name: &'static str,
-    request: Req,
-) -> lance_core::Result<Resp>
-where
-    Req: serde::Serialize + Send + 'static,
-    Resp: for<'py> pyo3::FromPyObject<'py> + Send + 'static,
-{
-    let request_json = serde_json::to_string(&request).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to serialize request for {}: {}",
-            method_name, e
-        ))
-    })?;
-
-    tokio::task::spawn_blocking(move || {
-        Python::attach(|py| {
-            let json_module = py.import("json")?;
-            let request_dict = json_module.call_method1("loads", (&request_json,))?;
-
-            // Wrap dict in DictWithModelDump
-            let dict_class = get_dict_with_model_dump_class(py)?;
-            let request_arg = dict_class.call1((request_dict,))?;
-
-            // Call the Python method
-            let result = py_namespace.call_method1(py, method_name, (request_arg,))?;
-            let value: Resp = result.extract(py)?;
-            Ok::<_, PyErr>(value)
-        })
-    })
-    .await
-    .map_err(|e| lance_core::Error::io(format!("Task join error for {}: {}", method_name, e)))?
-    .map_err(|e: PyErr| lance_core::Error::io(format!("Python error in {}: {}", method_name, e)))
-}
-
-/// Helper for methods that return Bytes
-async fn call_py_method_bytes<Req>(
-    py_namespace: Arc<Py<PyAny>>,
-    method_name: &'static str,
-    request: Req,
-) -> lance_core::Result<Bytes>
-where
-    Req: serde::Serialize + Send + 'static,
-{
-    let request_json = serde_json::to_string(&request).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to serialize request for {}: {}",
-            method_name, e
-        ))
-    })?;
-
-    tokio::task::spawn_blocking(move || {
-        Python::attach(|py| {
-            let json_module = py.import("json")?;
-            let request_dict = json_module.call_method1("loads", (&request_json,))?;
-
-            // Wrap dict in DictWithModelDump
-            let dict_class = get_dict_with_model_dump_class(py)?;
-            let request_arg = dict_class.call1((request_dict,))?;
-
-            // Call the Python method
-            let result = py_namespace.call_method1(py, method_name, (request_arg,))?;
-            let bytes_data: Vec<u8> = result.extract(py)?;
-            Ok::<_, PyErr>(Bytes::from(bytes_data))
-        })
-    })
-    .await
-    .map_err(|e| lance_core::Error::io(format!("Task join error for {}: {}", method_name, e)))?
-    .map_err(|e: PyErr| lance_core::Error::io(format!("Python error in {}: {}", method_name, e)))
-}
-
-/// Helper for methods that take request + data and return a response
-async fn call_py_method_with_data<Req, Resp>(
-    py_namespace: Arc<Py<PyAny>>,
-    method_name: &'static str,
-    request: Req,
-    data: Bytes,
-) -> lance_core::Result<Resp>
-where
-    Req: serde::Serialize + Send + 'static,
-    Resp: serde::de::DeserializeOwned + Send + 'static,
-{
-    let request_json = serde_json::to_string(&request).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to serialize request for {}: {}",
-            method_name, e
-        ))
-    })?;
-
-    let response_json = tokio::task::spawn_blocking(move || {
-        Python::attach(|py| {
-            let json_module = py.import("json")?;
-            let request_dict = json_module.call_method1("loads", (&request_json,))?;
-
-            // Wrap dict in DictWithModelDump
-            let dict_class = get_dict_with_model_dump_class(py)?;
-            let request_arg = dict_class.call1((request_dict,))?;
-
-            // Pass request and bytes to Python method
-            let py_bytes = pyo3::types::PyBytes::new(py, &data);
-            let result = py_namespace.call_method1(py, method_name, (request_arg, py_bytes))?;
-
-            // Convert response dict to JSON
-            let response_json: String = json_module.call_method1("dumps", (result,))?.extract()?;
-            Ok::<_, PyErr>(response_json)
-        })
-    })
-    .await
-    .map_err(|e| lance_core::Error::io(format!("Task join error for {}: {}", method_name, e)))?
-    .map_err(|e: PyErr| lance_core::Error::io(format!("Python error in {}: {}", method_name, e)))?;
-
-    serde_json::from_str(&response_json).map_err(|e| {
-        lance_core::Error::io(format!(
-            "Failed to deserialize response from {}: {}",
-            method_name, e
-        ))
-    })
-}
-
-#[async_trait]
-impl LanceNamespaceTrait for PyLanceNamespace {
-    fn namespace_id(&self) -> String {
-        self.namespace_id.clone()
-    }
-
-    async fn list_namespaces(
-        &self,
-        request: ListNamespacesRequest,
-    ) -> lance_core::Result<ListNamespacesResponse> {
-        call_py_method(self.py_namespace.clone(), "list_namespaces", request).await
-    }
-
-    async fn describe_namespace(
-        &self,
-        request: DescribeNamespaceRequest,
-    ) -> lance_core::Result<DescribeNamespaceResponse> {
-        call_py_method(self.py_namespace.clone(), "describe_namespace", request).await
-    }
-
-    async fn create_namespace(
-        &self,
-        request: CreateNamespaceRequest,
-    ) -> lance_core::Result<CreateNamespaceResponse> {
-        call_py_method(self.py_namespace.clone(), "create_namespace", request).await
-    }
-
-    async fn drop_namespace(
-        &self,
-        request: DropNamespaceRequest,
-    ) -> lance_core::Result<DropNamespaceResponse> {
-        call_py_method(self.py_namespace.clone(), "drop_namespace", request).await
-    }
-
-    async fn namespace_exists(&self, request: NamespaceExistsRequest) -> lance_core::Result<()> {
-        call_py_method_unit(self.py_namespace.clone(), "namespace_exists", request).await
-    }
-
-    async fn list_tables(
-        &self,
-        request: ListTablesRequest,
-    ) -> lance_core::Result<ListTablesResponse> {
-        call_py_method(self.py_namespace.clone(), "list_tables", request).await
-    }
-
-    async fn describe_table(
-        &self,
-        request: DescribeTableRequest,
-    ) -> lance_core::Result<DescribeTableResponse> {
-        call_py_method(self.py_namespace.clone(), "describe_table", request).await
-    }
-
-    async fn register_table(
-        &self,
-        request: RegisterTableRequest,
-    ) -> lance_core::Result<RegisterTableResponse> {
-        call_py_method(self.py_namespace.clone(), "register_table", request).await
-    }
-
-    async fn table_exists(&self, request: TableExistsRequest) -> lance_core::Result<()> {
-        call_py_method_unit(self.py_namespace.clone(), "table_exists", request).await
-    }
-
-    async fn drop_table(&self, request: DropTableRequest) -> lance_core::Result<DropTableResponse> {
-        call_py_method(self.py_namespace.clone(), "drop_table", request).await
-    }
-
-    async fn deregister_table(
-        &self,
-        request: DeregisterTableRequest,
-    ) -> lance_core::Result<DeregisterTableResponse> {
-        call_py_method(self.py_namespace.clone(), "deregister_table", request).await
-    }
-
-    async fn count_table_rows(&self, request: CountTableRowsRequest) -> lance_core::Result<i64> {
-        call_py_method_primitive(self.py_namespace.clone(), "count_table_rows", request).await
-    }
-
-    async fn create_table(
-        &self,
-        request: CreateTableRequest,
-        request_data: Bytes,
-    ) -> lance_core::Result<CreateTableResponse> {
-        call_py_method_with_data(
-            self.py_namespace.clone(),
-            "create_table",
-            request,
-            request_data,
-        )
-        .await
-    }
-
-    async fn declare_table(
-        &self,
-        request: DeclareTableRequest,
-    ) -> lance_core::Result<DeclareTableResponse> {
-        call_py_method(self.py_namespace.clone(), "declare_table", request).await
-    }
-
-    async fn insert_into_table(
-        &self,
-        request: InsertIntoTableRequest,
-        request_data: Bytes,
-    ) -> lance_core::Result<InsertIntoTableResponse> {
-        call_py_method_with_data(
-            self.py_namespace.clone(),
-            "insert_into_table",
-            request,
-            request_data,
-        )
-        .await
-    }
-
-    async fn merge_insert_into_table(
-        &self,
-        request: MergeInsertIntoTableRequest,
-        request_data: Bytes,
-    ) -> lance_core::Result<MergeInsertIntoTableResponse> {
-        call_py_method_with_data(
-            self.py_namespace.clone(),
-            "merge_insert_into_table",
-            request,
-            request_data,
-        )
-        .await
-    }
-
-    async fn update_table(
-        &self,
-        request: UpdateTableRequest,
-    ) -> lance_core::Result<UpdateTableResponse> {
-        call_py_method(self.py_namespace.clone(), "update_table", request).await
-    }
-
-    async fn delete_from_table(
-        &self,
-        request: DeleteFromTableRequest,
-    ) -> lance_core::Result<DeleteFromTableResponse> {
-        call_py_method(self.py_namespace.clone(), "delete_from_table", request).await
-    }
-
-    async fn query_table(&self, request: QueryTableRequest) -> lance_core::Result<Bytes> {
-        call_py_method_bytes(self.py_namespace.clone(), "query_table", request).await
-    }
-
-    async fn create_table_index(
-        &self,
-        request: CreateTableIndexRequest,
-    ) -> lance_core::Result<CreateTableIndexResponse> {
-        call_py_method(self.py_namespace.clone(), "create_table_index", request).await
-    }
-
-    async fn list_table_indices(
-        &self,
-        request: ListTableIndicesRequest,
-    ) -> lance_core::Result<ListTableIndicesResponse> {
-        call_py_method(self.py_namespace.clone(), "list_table_indices", request).await
-    }
-
-    async fn describe_table_index_stats(
-        &self,
-        request: DescribeTableIndexStatsRequest,
-    ) -> lance_core::Result<DescribeTableIndexStatsResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "describe_table_index_stats",
-            request,
-        )
-        .await
-    }
-
-    async fn describe_transaction(
-        &self,
-        request: DescribeTransactionRequest,
-    ) -> lance_core::Result<DescribeTransactionResponse> {
-        call_py_method(self.py_namespace.clone(), "describe_transaction", request).await
-    }
-
-    async fn alter_transaction(
-        &self,
-        request: AlterTransactionRequest,
-    ) -> lance_core::Result<AlterTransactionResponse> {
-        call_py_method(self.py_namespace.clone(), "alter_transaction", request).await
-    }
-
-    async fn create_table_scalar_index(
-        &self,
-        request: CreateTableIndexRequest,
-    ) -> lance_core::Result<CreateTableScalarIndexResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "create_table_scalar_index",
-            request,
-        )
-        .await
-    }
-
-    async fn drop_table_index(
-        &self,
-        request: DropTableIndexRequest,
-    ) -> lance_core::Result<DropTableIndexResponse> {
-        call_py_method(self.py_namespace.clone(), "drop_table_index", request).await
-    }
-
-    async fn list_all_tables(
-        &self,
-        request: ListTablesRequest,
-    ) -> lance_core::Result<ListTablesResponse> {
-        call_py_method(self.py_namespace.clone(), "list_all_tables", request).await
-    }
-
-    async fn restore_table(
-        &self,
-        request: RestoreTableRequest,
-    ) -> lance_core::Result<RestoreTableResponse> {
-        call_py_method(self.py_namespace.clone(), "restore_table", request).await
-    }
-
-    async fn rename_table(
-        &self,
-        request: RenameTableRequest,
-    ) -> lance_core::Result<RenameTableResponse> {
-        call_py_method(self.py_namespace.clone(), "rename_table", request).await
-    }
-
-    async fn list_table_versions(
-        &self,
-        request: ListTableVersionsRequest,
-    ) -> lance_core::Result<ListTableVersionsResponse> {
-        call_py_method(self.py_namespace.clone(), "list_table_versions", request).await
-    }
-
-    async fn create_table_version(
-        &self,
-        request: CreateTableVersionRequest,
-    ) -> lance_core::Result<CreateTableVersionResponse> {
-        call_py_method(self.py_namespace.clone(), "create_table_version", request).await
-    }
-
-    async fn describe_table_version(
-        &self,
-        request: DescribeTableVersionRequest,
-    ) -> lance_core::Result<DescribeTableVersionResponse> {
-        call_py_method(self.py_namespace.clone(), "describe_table_version", request).await
-    }
-
-    async fn batch_delete_table_versions(
-        &self,
-        request: BatchDeleteTableVersionsRequest,
-    ) -> lance_core::Result<BatchDeleteTableVersionsResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "batch_delete_table_versions",
-            request,
-        )
-        .await
-    }
-
-    async fn update_table_schema_metadata(
-        &self,
-        request: UpdateTableSchemaMetadataRequest,
-    ) -> lance_core::Result<UpdateTableSchemaMetadataResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "update_table_schema_metadata",
-            request,
-        )
-        .await
-    }
-
-    async fn get_table_stats(
-        &self,
-        request: GetTableStatsRequest,
-    ) -> lance_core::Result<GetTableStatsResponse> {
-        call_py_method(self.py_namespace.clone(), "get_table_stats", request).await
-    }
-
-    async fn explain_table_query_plan(
-        &self,
-        request: ExplainTableQueryPlanRequest,
-    ) -> lance_core::Result<String> {
-        call_py_method_primitive(
-            self.py_namespace.clone(),
-            "explain_table_query_plan",
-            request,
-        )
-        .await
-    }
-
-    async fn analyze_table_query_plan(
-        &self,
-        request: AnalyzeTableQueryPlanRequest,
-    ) -> lance_core::Result<String> {
-        call_py_method_primitive(
-            self.py_namespace.clone(),
-            "analyze_table_query_plan",
-            request,
-        )
-        .await
-    }
-
-    async fn alter_table_add_columns(
-        &self,
-        request: AlterTableAddColumnsRequest,
-    ) -> lance_core::Result<AlterTableAddColumnsResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "alter_table_add_columns",
-            request,
-        )
-        .await
-    }
-
-    async fn alter_table_alter_columns(
-        &self,
-        request: AlterTableAlterColumnsRequest,
-    ) -> lance_core::Result<AlterTableAlterColumnsResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "alter_table_alter_columns",
-            request,
-        )
-        .await
-    }
-
-    async fn alter_table_drop_columns(
-        &self,
-        request: AlterTableDropColumnsRequest,
-    ) -> lance_core::Result<AlterTableDropColumnsResponse> {
-        call_py_method(
-            self.py_namespace.clone(),
-            "alter_table_drop_columns",
-            request,
-        )
-        .await
-    }
-
-    async fn list_table_tags(
-        &self,
-        request: ListTableTagsRequest,
-    ) -> lance_core::Result<ListTableTagsResponse> {
-        call_py_method(self.py_namespace.clone(), "list_table_tags", request).await
-    }
-
-    async fn create_table_tag(
-        &self,
-        request: CreateTableTagRequest,
-    ) -> lance_core::Result<CreateTableTagResponse> {
-        call_py_method(self.py_namespace.clone(), "create_table_tag", request).await
-    }
-
-    async fn delete_table_tag(
-        &self,
-        request: DeleteTableTagRequest,
-    ) -> lance_core::Result<DeleteTableTagResponse> {
-        call_py_method(self.py_namespace.clone(), "delete_table_tag", request).await
-    }
-
-    async fn update_table_tag(
-        &self,
-        request: UpdateTableTagRequest,
-    ) -> lance_core::Result<UpdateTableTagResponse> {
-        call_py_method(self.py_namespace.clone(), "update_table_tag", request).await
-    }
-
-    async fn get_table_tag_version(
-        &self,
-        request: GetTableTagVersionRequest,
-    ) -> lance_core::Result<GetTableTagVersionResponse> {
-        call_py_method(self.py_namespace.clone(), "get_table_tag_version", request).await
-    }
-}
-
-/// Convert Python dict to HashMap<String, String>
-#[allow(dead_code)]
-fn dict_to_hashmap(dict: &Bound<'_, PyDict>) -> PyResult<HashMap<String, String>> {
-    let mut map = HashMap::new();
-    for (key, value) in dict.iter() {
-        let key_str: String = key.extract()?;
-        let value_str: String = value.extract()?;
-        map.insert(key_str, value_str);
-    }
-    Ok(map)
-}
-
-/// Extract an Arc<dyn LanceNamespace> from a Python namespace object.
-///
-/// This function wraps any Python namespace object with PyLanceNamespace.
-/// The PyLanceNamespace wrapper uses DictWithModelDump to pass requests,
-/// which works with both:
-/// - Native namespaces (DirectoryNamespace, RestNamespace) that use depythonize (expects dict)
-/// - Custom Python implementations that call .model_dump() on the request
-pub fn extract_namespace_arc(
-    py: Python<'_>,
-    ns: Py<PyAny>,
-) -> PyResult<Arc<dyn LanceNamespaceTrait>> {
-    let ns_ref = ns.bind(py);
-    PyLanceNamespace::create_arc(py, ns_ref)
-}
--- a/python/src/table.rs
+++ b/python/src/table.rs
@@ -710,6 +710,9 @@ impl Table {
        if let Some(use_index) = parameters.use_index {
            builder.use_index(use_index);
        }
+        if let Some(mem_wal) = parameters.mem_wal {
+            builder.mem_wal(mem_wal);
+        }

        future_into_py(self_.py(), async move {
            let res = builder.execute(Box::new(batches)).await.infer_error()?;
@@ -870,6 +873,7 @@ pub struct MergeInsertParams {
    when_not_matched_by_source_condition: Option<String>,
    timeout: Option<std::time::Duration>,
    use_index: Option<bool>,
+    mem_wal: Option<bool>,
 }

 #[pyclass]
--- a/python/uv.lock
+++ b/python/uv.lock
@@ -2006,7 +2006,7 @@ requires-dist = [
    { name = "botocore", marker = "extra == 'embeddings'", specifier = ">=1.31.57" },
    { name = "cohere", marker = "extra == 'embeddings'" },
    { name = "colpali-engine", marker = "extra == 'embeddings'", specifier = ">=0.3.10" },
-    { name = "datafusion", marker = "extra == 'tests'", specifier = "<52" },
+    { name = "datafusion", marker = "extra == 'tests'" },
    { name = "deprecation" },
    { name = "duckdb", marker = "extra == 'tests'" },
    { name = "google-generativeai", marker = "extra == 'embeddings'" },
@@ -2035,7 +2035,7 @@ requires-dist = [
    { name = "pyarrow-stubs", marker = "extra == 'tests'" },
    { name = "pydantic", specifier = ">=1.10" },
    { name = "pylance", marker = "extra == 'pylance'", specifier = ">=1.0.0b14" },
-    { name = "pylance", marker = "extra == 'tests'", specifier = ">=1.0.0b14,<3.0.0" },
+    { name = "pylance", marker = "extra == 'tests'", specifier = ">=1.0.0b14" },
    { name = "pyright", marker = "extra == 'dev'" },
    { name = "pytest", marker = "extra == 'tests'" },
    { name = "pytest-asyncio", marker = "extra == 'tests'" },
--- a/rust/lancedb/Cargo.toml
+++ b/rust/lancedb/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "lancedb"
-version = "0.27.0-beta.5"
+version = "0.27.0-beta.3"
 edition.workspace = true
 description = "LanceDB: A serverless, low-latency vector database for AI applications"
 license.workspace = true
--- a/rust/lancedb/README.md
+++ b/rust/lancedb/README.md
@@ -1,4 +1,4 @@
-# LanceDB Rust SDK
+# LanceDB Rust

 <a href="https://crates.io/crates/vectordb">![img](https://img.shields.io/crates/v/vectordb)</a>
 <a href="https://docs.rs/vectordb/latest/vectordb/">![Docs.rs](https://img.shields.io/docsrs/vectordb)</a>
--- a/rust/lancedb/src/connection.rs
+++ b/rust/lancedb/src/connection.rs
@@ -136,7 +136,6 @@ impl OpenTableBuilder {
                lance_read_params: None,
                location: None,
                namespace_client: None,
-                managed_versioning: None,
            },
            embedding_registry,
        }
@@ -236,29 +235,6 @@ impl OpenTableBuilder {
        self
    }

-    /// Set a namespace client for managed versioning support.
-    ///
-    /// When a namespace client is provided and the table has `managed_versioning` enabled,
-    /// the table will use the namespace's commit handler to notify the namespace of
-    /// version changes. This enables features like event emission for table modifications.
-    pub fn namespace_client(mut self, client: Arc<dyn lance_namespace::LanceNamespace>) -> Self {
-        self.request.namespace_client = Some(client);
-        self
-    }
-
-    /// Set whether managed versioning is enabled for this table.
-    ///
-    /// When set to `Some(true)`, the table will use namespace-managed commits.
-    /// When set to `Some(false)`, the table will use local commits even if namespace_client is set.
-    /// When set to `None` (default), the value will be fetched from the namespace if namespace_client is set.
-    ///
-    /// This is typically set when the caller has already queried the namespace and knows the
-    /// managed_versioning status, avoiding a redundant describe_table call.
-    pub fn managed_versioning(mut self, enabled: bool) -> Self {
-        self.request.managed_versioning = Some(enabled);
-        self
-    }
-
    /// Open the table
    pub async fn execute(self) -> Result<Table> {
        let table = self.parent.open_table(self.request).await?;
@@ -318,12 +294,6 @@ impl CloneTableBuilder {
        self
    }

-    /// Set a namespace client for managed versioning support.
-    pub fn namespace_client(mut self, client: Arc<dyn lance_namespace::LanceNamespace>) -> Self {
-        self.request.namespace_client = Some(client);
-        self
-    }
-
    /// Execute the clone operation
    pub async fn execute(self) -> Result<Table> {
        let parent = self.parent.clone();
@@ -814,13 +784,19 @@ impl ConnectBuilder {
            message: "An api_key is required when connecting to LanceDb Cloud".to_string(),
        })?;

+        // Propagate mem_wal_enabled from options to client_config
+        let mut client_config = self.request.client_config;
+        if options.mem_wal_enabled.is_some() {
+            client_config.mem_wal_enabled = options.mem_wal_enabled;
+        }
+
        let storage_options = StorageOptions(options.storage_options.clone());
        let internal = Arc::new(crate::remote::db::RemoteDatabase::try_new(
            &self.request.uri,
            &api_key,
            &region,
            options.host_override,
-            self.request.client_config,
+            client_config,
            storage_options.into(),
        )?);
        Ok(Connection {
--- a/rust/lancedb/src/database.rs
+++ b/rust/lancedb/src/database.rs
@@ -66,10 +66,6 @@ pub struct OpenTableRequest {
    /// Optional namespace client for server-side query execution.
    /// When set, queries will be executed on the namespace server instead of locally.
    pub namespace_client: Option<Arc<dyn LanceNamespace>>,
-    /// Whether managed versioning is enabled for this table.
-    /// When Some(true), the table will use namespace-managed commits instead of local commits.
-    /// When None and namespace_client is provided, the value will be fetched from the namespace.
-    pub managed_versioning: Option<bool>,
 }

 impl std::fmt::Debug for OpenTableRequest {
@@ -81,7 +77,6 @@ impl std::fmt::Debug for OpenTableRequest {
            .field("lance_read_params", &self.lance_read_params)
            .field("location", &self.location)
            .field("namespace_client", &self.namespace_client)
-            .field("managed_versioning", &self.managed_versioning)
            .finish()
    }
 }
@@ -166,9 +161,6 @@ pub struct CloneTableRequest {
    /// Whether to perform a shallow clone (true) or deep clone (false). Defaults to true.
    /// Currently only shallow clone is supported.
    pub is_shallow: bool,
-    /// Optional namespace client for managed versioning support.
-    /// When set, enables the commit handler to track table versions through the namespace.
-    pub namespace_client: Option<Arc<dyn LanceNamespace>>,
 }

 impl CloneTableRequest {
@@ -180,7 +172,6 @@ impl CloneTableRequest {
            source_version: None,
            source_tag: None,
            is_shallow: true,
-            namespace_client: None,
        }
    }
 }
--- a/rust/lancedb/src/database/listing.rs
+++ b/rust/lancedb/src/database/listing.rs
@@ -669,7 +669,6 @@ impl ListingDatabase {
                    lance_read_params: None,
                    location: None,
                    namespace_client: None,
-                    managed_versioning: None,
                };
                let req = (callback)(req);
                let table = self.open_table(req).await?;
@@ -870,7 +869,6 @@ impl Database for ListingDatabase {
            Some(write_params),
            self.read_consistency_interval,
            request.namespace_client,
-            false, // server_side_query_enabled - listing database doesn't support server-side queries
        )
        .await
        {
@@ -948,9 +946,7 @@ impl Database for ListingDatabase {
            self.store_wrapper.clone(),
            None,
            self.read_consistency_interval,
-            request.namespace_client,
-            false, // server_side_query_enabled - listing database doesn't support server-side queries
-            None,  // managed_versioning - will be queried if namespace_client is provided
+            None,
        )
        .await?;

@@ -1026,8 +1022,6 @@ impl Database for ListingDatabase {
                Some(read_params),
                self.read_consistency_interval,
                request.namespace_client,
-                false, // server_side_query_enabled - listing database doesn't support server-side queries
-                request.managed_versioning, // Pass through managed_versioning from request
            )
            .await?,
        );
@@ -1168,7 +1162,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await
            .unwrap();
@@ -1229,7 +1222,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await
            .unwrap();
@@ -1289,7 +1281,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await;

@@ -1326,7 +1317,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: false, // Request deep clone
-                namespace_client: None,
            })
            .await;

@@ -1367,7 +1357,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await;

@@ -1408,7 +1397,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await;

@@ -1428,7 +1416,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await;

@@ -1465,7 +1452,6 @@ mod tests {
                source_version: Some(1),
                source_tag: Some("v1.0".to_string()),
                is_shallow: true,
-                namespace_client: None,
            })
            .await;

@@ -1539,7 +1525,6 @@ mod tests {
                source_version: Some(initial_version),
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await
            .unwrap();
@@ -1618,7 +1603,6 @@ mod tests {
                source_version: None,
                source_tag: Some("v1.0".to_string()),
                is_shallow: true,
-                namespace_client: None,
            })
            .await
            .unwrap();
@@ -1670,7 +1654,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await
            .unwrap();
@@ -1763,7 +1746,6 @@ mod tests {
                source_version: None,
                source_tag: None,
                is_shallow: true,
-                namespace_client: None,
            })
            .await
            .unwrap();
--- a/rust/lancedb/src/database/namespace.rs
+++ b/rust/lancedb/src/database/namespace.rs
@@ -7,7 +7,6 @@ use std::collections::HashMap;
 use std::sync::Arc;

 use async_trait::async_trait;
-use lance::io::commit::namespace_manifest::LanceNamespaceExternalManifestStore;
 use lance_io::object_store::{ObjectStoreParams, StorageOptionsAccessor};
 use lance_namespace::{
    LanceNamespace,
@@ -19,8 +18,6 @@ use lance_namespace::{
    },
 };
 use lance_namespace_impls::ConnectBuilder;
-use lance_table::io::commit::CommitHandler;
-use lance_table::io::commit::external_manifest::ExternalManifestCommitHandler;

 use crate::database::ReadConsistency;
 use crate::error::{Error, Result};
@@ -208,12 +205,14 @@ impl Database for LanceNamespaceDatabase {
        let mut table_id = request.namespace.clone();
        table_id.push(request.name.clone());

+        // Try declare_table first, falling back to create_empty_table for backwards
+        // compatibility with older namespace clients that don't support declare_table
        let declare_request = DeclareTableRequest {
            id: Some(table_id.clone()),
            ..Default::default()
        };

-        let (location, initial_storage_options, managed_versioning) = {
+        let (location, initial_storage_options) = {
            let response = self.namespace.declare_table(declare_request).await?;
            let loc = response.location.ok_or_else(|| Error::Runtime {
                message: "Table location is missing from declare_table response".to_string(),
@@ -223,33 +222,21 @@ impl Database for LanceNamespaceDatabase {
                .storage_options
                .or_else(|| Some(self.storage_options.clone()))
                .filter(|o| !o.is_empty());
-            (loc, opts, response.managed_versioning)
+            (loc, opts)
        };

-        // Build write params with storage options and commit handler
-        let mut params = request.write_options.lance_write_params.unwrap_or_default();
-
-        // Set up storage options if provided
-        if let Some(storage_opts) = initial_storage_options {
+        let write_params = if let Some(storage_opts) = initial_storage_options {
+            let mut params = request.write_options.lance_write_params.unwrap_or_default();
            let store_params = params
                .store_params
                .get_or_insert_with(ObjectStoreParams::default);
            store_params.storage_options_accessor = Some(Arc::new(
                StorageOptionsAccessor::with_static_options(storage_opts),
            ));
-        }
-
-        // Set up commit handler when managed_versioning is enabled
-        if managed_versioning == Some(true) {
-            let external_store =
-                LanceNamespaceExternalManifestStore::new(self.namespace.clone(), table_id.clone());
-            let commit_handler: Arc<dyn CommitHandler> = Arc::new(ExternalManifestCommitHandler {
-                external_manifest_store: Arc::new(external_store),
-            });
-            params.commit_handler = Some(commit_handler);
-        }
-
-        let write_params = Some(params);
+            Some(params)
+        } else {
+            request.write_options.lance_write_params
+        };

        let native_table = NativeTable::create_from_namespace(
            self.namespace.clone(),
--- a/rust/lancedb/src/remote/client.rs
+++ b/rust/lancedb/src/remote/client.rs
@@ -14,6 +14,7 @@ use crate::remote::db::RemoteOptions;
 use crate::remote::retry::{ResolvedRetryConfig, RetryCounter};

 const REQUEST_ID_HEADER: HeaderName = HeaderName::from_static("x-request-id");
+const MEM_WAL_ENABLED_HEADER: HeaderName = HeaderName::from_static("x-lancedb-mem-wal-enabled");

 /// Configuration for TLS/mTLS settings.
 #[derive(Clone, Debug, Default)]
@@ -52,6 +53,10 @@ pub struct ClientConfig {
    pub tls_config: Option<TlsConfig>,
    /// Provider for custom headers to be added to each request
    pub header_provider: Option<Arc<dyn HeaderProvider>>,
+    /// Enable MemWAL write path for streaming writes.
+    /// When true, write operations will use the MemWAL architecture
+    /// for high-performance streaming writes.
+    pub mem_wal_enabled: Option<bool>,
 }

 impl std::fmt::Debug for ClientConfig {
@@ -67,6 +72,7 @@ impl std::fmt::Debug for ClientConfig {
                "header_provider",
                &self.header_provider.as_ref().map(|_| "Some(...)"),
            )
+            .field("mem_wal_enabled", &self.mem_wal_enabled)
            .finish()
    }
 }
@@ -81,6 +87,7 @@ impl Default for ClientConfig {
            id_delimiter: None,
            tls_config: None,
            header_provider: None,
+            mem_wal_enabled: None,
        }
    }
 }
@@ -477,6 +484,11 @@ impl<S: HttpSend> RestfulLanceDbClient<S> {
            );
        }

+        // Add MemWAL header if enabled
+        if let Some(true) = config.mem_wal_enabled {
+            headers.insert(MEM_WAL_ENABLED_HEADER, HeaderValue::from_static("true"));
+        }
+
        Ok(headers)
    }

--- a/rust/lancedb/src/remote/db.rs
+++ b/rust/lancedb/src/remote/db.rs
@@ -78,6 +78,7 @@ pub const OPT_REMOTE_PREFIX: &str = "remote_database_";
 pub const OPT_REMOTE_API_KEY: &str = "remote_database_api_key";
 pub const OPT_REMOTE_REGION: &str = "remote_database_region";
 pub const OPT_REMOTE_HOST_OVERRIDE: &str = "remote_database_host_override";
+pub const OPT_REMOTE_MEM_WAL_ENABLED: &str = "remote_database_mem_wal_enabled";
 // TODO: add support for configuring client config via key/value options

 #[derive(Clone, Debug, Default)]
@@ -98,6 +99,12 @@ pub struct RemoteDatabaseOptions {
    /// These options are only used for LanceDB Enterprise and only a subset of options
    /// are supported.
    pub storage_options: HashMap<String, String>,
+    /// Enable MemWAL write path for high-performance streaming writes.
+    ///
+    /// When enabled, write operations (insert, merge_insert, etc.) will use
+    /// the MemWAL architecture which buffers writes in memory and Write-Ahead Log
+    /// before asynchronously merging to the base table.
+    pub mem_wal_enabled: Option<bool>,
 }

 impl RemoteDatabaseOptions {
@@ -109,6 +116,9 @@ impl RemoteDatabaseOptions {
        let api_key = map.get(OPT_REMOTE_API_KEY).cloned();
        let region = map.get(OPT_REMOTE_REGION).cloned();
        let host_override = map.get(OPT_REMOTE_HOST_OVERRIDE).cloned();
+        let mem_wal_enabled = map
+            .get(OPT_REMOTE_MEM_WAL_ENABLED)
+            .map(|v| v.to_lowercase() == "true");
        let storage_options = map
            .iter()
            .filter(|(key, _)| !key.starts_with(OPT_REMOTE_PREFIX))
@@ -119,6 +129,7 @@ impl RemoteDatabaseOptions {
            region,
            host_override,
            storage_options,
+            mem_wal_enabled,
        })
    }
 }
@@ -137,6 +148,12 @@ impl DatabaseOptions for RemoteDatabaseOptions {
        if let Some(host_override) = &self.host_override {
            map.insert(OPT_REMOTE_HOST_OVERRIDE.to_string(), host_override.clone());
        }
+        if let Some(mem_wal_enabled) = &self.mem_wal_enabled {
+            map.insert(
+                OPT_REMOTE_MEM_WAL_ENABLED.to_string(),
+                mem_wal_enabled.to_string(),
+            );
+        }
    }
 }

@@ -181,6 +198,20 @@ impl RemoteDatabaseOptionsBuilder {
        self.options.host_override = Some(host_override);
        self
    }
+
+    /// Enable MemWAL write path for high-performance streaming writes.
+    ///
+    /// When enabled, write operations will use the MemWAL architecture
+    /// which buffers writes in memory and Write-Ahead Log before
+    /// asynchronously merging to the base table.
+    ///
+    /// # Arguments
+    ///
+    /// * `enabled` - Whether to enable MemWAL writes
+    pub fn mem_wal_enabled(mut self, enabled: bool) -> Self {
+        self.options.mem_wal_enabled = Some(enabled);
+        self
+    }
 }

 #[derive(Debug)]
@@ -464,7 +495,6 @@ impl<S: HttpSend> Database for RemoteDatabase<S> {
                            lance_read_params: None,
                            location: None,
                            namespace_client: None,
-                            managed_versioning: None,
                        };
                        let req = (callback)(req);
                        self.open_table(req).await
--- a/rust/lancedb/src/remote/table.rs
+++ b/rust/lancedb/src/remote/table.rs
@@ -62,6 +62,7 @@ use std::time::Duration;
 use tokio::sync::RwLock;

 const REQUEST_TIMEOUT_HEADER: HeaderName = HeaderName::from_static("x-request-timeout-ms");
+const MEM_WAL_ENABLED_HEADER: HeaderName = HeaderName::from_static("x-lancedb-mem-wal-enabled");
 const METRIC_TYPE_KEY: &str = "metric_type";
 const INDEX_TYPE_KEY: &str = "index_type";
 const SCHEMA_CACHE_TTL: Duration = Duration::from_secs(30);
@@ -1359,6 +1360,7 @@ impl<S: HttpSend> BaseTable for RemoteTable<S> {
        self.check_mutable().await?;

        let timeout = params.timeout;
+        let mem_wal = params.mem_wal;

        let query = MergeInsertRequest::try_from(params)?;
        let mut request = self
@@ -1374,6 +1376,10 @@ impl<S: HttpSend> BaseTable for RemoteTable<S> {
            }
        }

+        if mem_wal {
+            request = request.header(MEM_WAL_ENABLED_HEADER, "true");
+        }
+
        let (request_id, response) = self.send_streaming(request, new_data, true).await?;

        let response = self.check_table_response(&request_id, response).await?;
--- a/rust/lancedb/src/table.rs
+++ b/rust/lancedb/src/table.rs
@@ -34,13 +34,9 @@ use lance_index::vector::sq::builder::SQBuildParams;
 use lance_io::object_store::{LanceNamespaceStorageOptionsProvider, StorageOptionsAccessor};
 pub use query::AnyQuery;

-use lance::io::commit::namespace_manifest::LanceNamespaceExternalManifestStore;
 use lance_namespace::LanceNamespace;
-use lance_namespace::models::DescribeTableRequest;
 use lance_table::format::Manifest;
-use lance_table::io::commit::CommitHandler;
 use lance_table::io::commit::ManifestNamingScheme;
-use lance_table::io::commit::external_manifest::ExternalManifestCommitHandler;
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::format;
@@ -1216,13 +1212,10 @@ pub struct NativeTable {
    // This comes from the connection options. We store here so we can pass down
    // to the dataset when we recreate it (for example, in checkout_latest).
    read_consistency_interval: Option<std::time::Duration>,
-    // Optional namespace client for namespace operations (e.g., managed versioning).
-    // pub(crate) so query.rs can access the field for server-side query execution.
+    // Optional namespace client for server-side query execution.
+    // When set, queries will be executed on the namespace server instead of locally.
+    // pub (crate) namespace_client so query.rs can access the fields
    pub(crate) namespace_client: Option<Arc<dyn LanceNamespace>>,
-    // Whether to enable server-side query execution via the namespace client.
-    // When true and namespace_client is set, queries will be executed on the
-    // namespace server instead of locally.
-    pub(crate) server_side_query_enabled: bool,
 }

 impl std::fmt::Debug for NativeTable {
@@ -1234,7 +1227,6 @@ impl std::fmt::Debug for NativeTable {
            .field("uri", &self.uri)
            .field("read_consistency_interval", &self.read_consistency_interval)
            .field("namespace_client", &self.namespace_client)
-            .field("server_side_query_enabled", &self.server_side_query_enabled)
            .finish()
    }
 }
@@ -1271,7 +1263,7 @@ impl NativeTable {
    /// * A [NativeTable] object.
    pub async fn open(uri: &str) -> Result<Self> {
        let name = Self::get_table_name(uri)?;
-        Self::open_with_params(uri, &name, vec![], None, None, None, None, false, None).await
+        Self::open_with_params(uri, &name, vec![], None, None, None, None).await
    }

    /// Opens an existing Table
@@ -1281,10 +1273,7 @@ impl NativeTable {
    /// * `base_path` - The base path where the table is located
    /// * `name` The Table name
    /// * `params` The [ReadParams] to use when opening the table
-    /// * `namespace_client` - Optional namespace client for namespace operations
-    /// * `server_side_query_enabled` - Whether to enable server-side query execution
-    /// * `managed_versioning` - Whether managed versioning is enabled. If None and namespace_client
-    ///   is provided, the value will be fetched via describe_table.
+    /// * `namespace_client` - Optional namespace client for server-side query execution
    ///
    /// # Returns
    ///
@@ -1298,8 +1287,6 @@ impl NativeTable {
        params: Option<ReadParams>,
        read_consistency_interval: Option<std::time::Duration>,
        namespace_client: Option<Arc<dyn LanceNamespace>>,
-        server_side_query_enabled: bool,
-        managed_versioning: Option<bool>,
    ) -> Result<Self> {
        let params = params.unwrap_or_default();
        // patch the params if we have a write store wrapper
@@ -1308,54 +1295,17 @@ impl NativeTable {
            None => params,
        };

-        // Build table_id from namespace + name
-        let mut table_id = namespace.clone();
-        table_id.push(name.to_string());
-
-        // Determine if managed_versioning is enabled
-        // Use the provided value if available, otherwise query the namespace
-        let managed_versioning = match managed_versioning {
-            Some(value) => value,
-            None if namespace_client.is_some() => {
-                let ns_client = namespace_client.as_ref().unwrap();
-                let describe_request = DescribeTableRequest {
-                    id: Some(table_id.clone()),
-                    ..Default::default()
-                };
-                let response = ns_client
-                    .describe_table(describe_request)
-                    .await
-                    .map_err(|e| Error::Runtime {
-                        message: format!(
-                            "Failed to describe table via namespace client: {}. \
-                             If you don't need managed versioning, don't pass namespace_client.",
-                            e
-                        ),
-                    })?;
-                response.managed_versioning == Some(true)
-            }
-            None => false,
-        };
-
-        let mut builder = DatasetBuilder::from_uri(uri).with_read_params(params);
-
-        // Set up commit handler when managed_versioning is enabled
-        if managed_versioning && let Some(ref ns_client) = namespace_client {
-            let external_store =
-                LanceNamespaceExternalManifestStore::new(ns_client.clone(), table_id.clone());
-            let commit_handler: Arc<dyn CommitHandler> = Arc::new(ExternalManifestCommitHandler {
-                external_manifest_store: Arc::new(external_store),
-            });
-            builder = builder.with_commit_handler(commit_handler);
-        }
-
-        let dataset = builder.load().await.map_err(|e| match e {
-            lance::Error::DatasetNotFound { .. } => Error::TableNotFound {
-                name: name.to_string(),
-                source: Box::new(e),
-            },
-            e => e.into(),
-        })?;
+        let dataset = DatasetBuilder::from_uri(uri)
+            .with_read_params(params)
+            .load()
+            .await
+            .map_err(|e| match e {
+                lance::Error::DatasetNotFound { .. } => Error::TableNotFound {
+                    name: name.to_string(),
+                    source: Box::new(e),
+                },
+                e => e.into(),
+            })?;

        let dataset = DatasetConsistencyWrapper::new_latest(dataset, read_consistency_interval);
        let id = Self::build_id(&namespace, name);
@@ -1368,7 +1318,6 @@ impl NativeTable {
            dataset,
            read_consistency_interval,
            namespace_client,
-            server_side_query_enabled,
        })
    }

@@ -1472,7 +1421,6 @@ impl NativeTable {
            dataset,
            read_consistency_interval,
            namespace_client: stored_namespace_client,
-            server_side_query_enabled,
        })
    }

@@ -1512,8 +1460,7 @@ impl NativeTable {
    /// * `namespace` - The namespace path. When non-empty, an explicit URI must be provided.
    /// * `batches` RecordBatch to be saved in the database.
    /// * `params` - Write parameters.
-    /// * `namespace_client` - Optional namespace client for namespace operations
-    /// * `server_side_query_enabled` - Whether to enable server-side query execution
+    /// * `namespace_client` - Optional namespace client for server-side query execution
    ///
    /// # Returns
    ///
@@ -1528,7 +1475,6 @@ impl NativeTable {
        params: Option<WriteParams>,
        read_consistency_interval: Option<std::time::Duration>,
        namespace_client: Option<Arc<dyn LanceNamespace>>,
-        server_side_query_enabled: bool,
    ) -> Result<Self> {
        // Default params uses format v1.
        let params = params.unwrap_or(WriteParams {
@@ -1561,7 +1507,6 @@ impl NativeTable {
            dataset: DatasetConsistencyWrapper::new_latest(dataset, read_consistency_interval),
            read_consistency_interval,
            namespace_client,
-            server_side_query_enabled,
        })
    }

@@ -1575,7 +1520,6 @@ impl NativeTable {
        params: Option<WriteParams>,
        read_consistency_interval: Option<std::time::Duration>,
        namespace_client: Option<Arc<dyn LanceNamespace>>,
-        server_side_query_enabled: bool,
    ) -> Result<Self> {
        let data: Box<dyn Scannable> = Box::new(RecordBatch::new_empty(schema));
        Self::create(
@@ -1587,7 +1531,6 @@ impl NativeTable {
            params,
            read_consistency_interval,
            namespace_client,
-            server_side_query_enabled,
        )
        .await
    }
@@ -1691,7 +1634,6 @@ impl NativeTable {
            dataset: DatasetConsistencyWrapper::new_latest(dataset, read_consistency_interval),
            read_consistency_interval,
            namespace_client: stored_namespace_client,
-            server_side_query_enabled,
        })
    }

@@ -2683,7 +2625,7 @@ mod tests {
            vec![Ok(batch.clone())],
            batch.schema(),
        ));
-        let table = NativeTable::create(uri, "test", vec![], reader, None, None, None, None, false)
+        let table = NativeTable::create(uri, "test", vec![], reader, None, None, None, None)
            .await
            .unwrap();

--- a/rust/lancedb/src/table/datafusion/cast.rs
+++ b/rust/lancedb/src/table/datafusion/cast.rs
@@ -3,13 +3,12 @@

 use std::sync::Arc;

-use arrow_cast::can_cast_types;
 use arrow_schema::{DataType, Field, FieldRef, Fields, Schema};
 use datafusion::functions::core::{get_field, named_struct};
 use datafusion_common::ScalarValue;
 use datafusion_common::config::ConfigOptions;
 use datafusion_physical_expr::ScalarFunctionExpr;
-use datafusion_physical_expr::expressions::{CastExpr, Literal};
+use datafusion_physical_expr::expressions::{Literal, cast};
 use datafusion_physical_plan::expressions::Column;
 use datafusion_physical_plan::projection::ProjectionExec;
 use datafusion_physical_plan::{ExecutionPlan, PhysicalExpr};
@@ -26,9 +25,12 @@ pub fn cast_to_table_schema(
        return Ok(input);
    }

-    let exprs = build_field_exprs(input_schema.fields(), table_schema.fields(), &|idx| {
-        Arc::new(Column::new(input_schema.field(idx).name(), idx)) as Arc<dyn PhysicalExpr>
-    })?;
+    let exprs = build_field_exprs(
+        input_schema.fields(),
+        table_schema.fields(),
+        &|idx| Arc::new(Column::new(input_schema.field(idx).name(), idx)) as Arc<dyn PhysicalExpr>,
+        &input_schema,
+    )?;

    let exprs: Vec<(Arc<dyn PhysicalExpr>, String)> = exprs
        .into_iter()
@@ -49,6 +51,7 @@ fn build_field_exprs(
    input_fields: &Fields,
    table_fields: &Fields,
    get_input_expr: &dyn Fn(usize) -> Arc<dyn PhysicalExpr>,
+    input_schema: &Schema,
 ) -> Result<Vec<(Arc<dyn PhysicalExpr>, FieldRef)>> {
    let config = Arc::new(ConfigOptions::default());
    let mut result = Vec::new();
@@ -69,19 +72,24 @@ fn build_field_exprs(
            (DataType::Struct(in_children), DataType::Struct(tbl_children))
                if in_children != tbl_children =>
            {
-                let sub_exprs = build_field_exprs(in_children, tbl_children, &|child_idx| {
-                    let child_name = in_children[child_idx].name();
-                    Arc::new(ScalarFunctionExpr::new(
-                        &format!("get_field({child_name})"),
-                        get_field(),
-                        vec![
-                            input_expr.clone(),
-                            Arc::new(Literal::new(ScalarValue::from(child_name.as_str()))),
-                        ],
-                        Arc::new(in_children[child_idx].as_ref().clone()),
-                        config.clone(),
-                    )) as Arc<dyn PhysicalExpr>
-                })?;
+                let sub_exprs = build_field_exprs(
+                    in_children,
+                    tbl_children,
+                    &|child_idx| {
+                        let child_name = in_children[child_idx].name();
+                        Arc::new(ScalarFunctionExpr::new(
+                            &format!("get_field({child_name})"),
+                            get_field(),
+                            vec![
+                                input_expr.clone(),
+                                Arc::new(Literal::new(ScalarValue::from(child_name.as_str()))),
+                            ],
+                            Arc::new(in_children[child_idx].as_ref().clone()),
+                            config.clone(),
+                        )) as Arc<dyn PhysicalExpr>
+                    },
+                    input_schema,
+                )?;

                let output_struct_fields: Fields = sub_exprs
                    .iter()
@@ -117,21 +125,17 @@ fn build_field_exprs(
            // Types match: pass through.
            (inp, tbl) if inp == tbl => input_expr,
            // Types differ: cast.
-            // safe: false (the default) means overflow/truncation errors surface at execution time.
-            (_, _) if can_cast_types(input_field.data_type(), table_field.data_type()) => Arc::new(
-                CastExpr::new(input_expr, table_field.data_type().clone(), None),
-            )
-                as Arc<dyn PhysicalExpr>,
-            (inp, tbl) => {
-                return Err(Error::InvalidInput {
+            _ => cast(input_expr, input_schema, table_field.data_type().clone()).map_err(|e| {
+                Error::InvalidInput {
                    message: format!(
-                        "cannot cast field '{}' from {} to {}",
+                        "cannot cast field '{}' from {} to {}: {}",
                        table_field.name(),
-                        inp,
-                        tbl,
+                        input_field.data_type(),
+                        table_field.data_type(),
+                        e
                    ),
-                });
-            }
+                }
+            })?,
        };

        let output_field = Arc::new(Field::new(
@@ -149,12 +153,10 @@ fn build_field_exprs(
 mod tests {
    use std::sync::Arc;

-    use arrow::buffer::OffsetBuffer;
    use arrow_array::{
-        Array, Float32Array, Float64Array, Int32Array, Int64Array, ListArray, RecordBatch,
-        StringArray, StructArray, UInt32Array, UInt64Array,
+        Float32Array, Float64Array, Int32Array, Int64Array, RecordBatch, StringArray, StructArray,
    };
-    use arrow_schema::{DataType, Field, Fields, Schema};
+    use arrow_schema::{DataType, Field, Schema};
    use datafusion::prelude::SessionContext;
    use datafusion_catalog::MemTable;
    use futures::TryStreamExt;
@@ -493,129 +495,4 @@ mod tests {
        assert_eq!(b.value(0), "hello");
        assert_eq!(b.value(1), "world");
    }
-
-    #[tokio::test]
-    async fn test_narrowing_numeric_cast_success() {
-        let input_batch = RecordBatch::try_new(
-            Arc::new(Schema::new(vec![Field::new("a", DataType::UInt64, false)])),
-            vec![Arc::new(UInt64Array::from(vec![1u64, 2, 3]))],
-        )
-        .unwrap();
-
-        let table_schema = Schema::new(vec![Field::new("a", DataType::UInt32, false)]);
-
-        let plan = plan_from_batch(input_batch).await;
-        let casted = cast_to_table_schema(plan, &table_schema).unwrap();
-        let result = collect(casted).await;
-
-        assert_eq!(result.schema().field(0).data_type(), &DataType::UInt32);
-        let a: &UInt32Array = result.column(0).as_any().downcast_ref().unwrap();
-        assert_eq!(a.values(), &[1u32, 2, 3]);
-    }
-
-    #[tokio::test]
-    async fn test_narrowing_numeric_cast_overflow_errors() {
-        let overflow_val = u32::MAX as u64 + 1;
-        let input_batch = RecordBatch::try_new(
-            Arc::new(Schema::new(vec![Field::new("a", DataType::UInt64, false)])),
-            vec![Arc::new(UInt64Array::from(vec![overflow_val]))],
-        )
-        .unwrap();
-
-        let table_schema = Schema::new(vec![Field::new("a", DataType::UInt32, false)]);
-
-        let plan = plan_from_batch(input_batch).await;
-        // Planning succeeds — the overflow is only detected at execution time.
-        let casted = cast_to_table_schema(plan, &table_schema).unwrap();
-
-        let ctx = SessionContext::new();
-        let stream = casted.execute(0, ctx.task_ctx()).unwrap();
-        let result: Result<Vec<RecordBatch>, _> = stream.try_collect().await;
-        assert!(result.is_err(), "expected overflow error at execution time");
-    }
-
-    #[tokio::test]
-    async fn test_list_struct_field_reorder() {
-        // list<struct<a: Int32, b: Int32>> → list<struct<b: Int64, a: Int64>>
-        // Tests both reordering (a,b → b,a) and element-type widening (Int32 → Int64).
-        let inner_fields: Fields = vec![
-            Field::new("a", DataType::Int32, true),
-            Field::new("b", DataType::Int32, true),
-        ]
-        .into();
-        let struct_array = StructArray::from(vec![
-            (
-                Arc::new(inner_fields[0].as_ref().clone()),
-                Arc::new(Int32Array::from(vec![1, 3])) as _,
-            ),
-            (
-                Arc::new(inner_fields[1].as_ref().clone()),
-                Arc::new(Int32Array::from(vec![2, 4])) as _,
-            ),
-        ]);
-        // Offsets: one list element containing two struct rows (0..2).
-        let offsets = OffsetBuffer::from_lengths(vec![2]);
-        let list_array = ListArray::try_new(
-            Arc::new(Field::new("item", DataType::Struct(inner_fields), true)),
-            offsets,
-            Arc::new(struct_array),
-            None,
-        )
-        .unwrap();
-        let input_batch = RecordBatch::try_new(
-            Arc::new(Schema::new(vec![Field::new(
-                "s_list",
-                list_array.data_type().clone(),
-                false,
-            )])),
-            vec![Arc::new(list_array)],
-        )
-        .unwrap();
-
-        let table_inner: Fields = vec![
-            Field::new("b", DataType::Int64, true),
-            Field::new("a", DataType::Int64, true),
-        ]
-        .into();
-        let table_schema = Schema::new(vec![Field::new(
-            "s_list",
-            DataType::List(Arc::new(Field::new(
-                "item",
-                DataType::Struct(table_inner),
-                true,
-            ))),
-            false,
-        )]);
-
-        let plan = plan_from_batch(input_batch).await;
-        let casted = cast_to_table_schema(plan, &table_schema).unwrap();
-        let result = collect(casted).await;
-
-        let list_col = result
-            .column(0)
-            .as_any()
-            .downcast_ref::<ListArray>()
-            .unwrap();
-        let struct_col = list_col
-            .values()
-            .as_any()
-            .downcast_ref::<StructArray>()
-            .unwrap();
-        assert_eq!(struct_col.num_columns(), 2);
-
-        let b: &Int64Array = struct_col
-            .column_by_name("b")
-            .unwrap()
-            .as_any()
-            .downcast_ref()
-            .unwrap();
-        assert_eq!(b.values(), &[2, 4]);
-        let a: &Int64Array = struct_col
-            .column_by_name("a")
-            .unwrap()
-            .as_any()
-            .downcast_ref()
-            .unwrap();
-        assert_eq!(a.values(), &[1, 3]);
-    }
 }
--- a/rust/lancedb/src/table/delete.rs
+++ b/rust/lancedb/src/table/delete.rs
@@ -1,4 +1,3 @@
-use futures::FutureExt;
 // SPDX-License-Identifier: Apache-2.0
 // SPDX-FileCopyrightText: Copyright The LanceDB Authors
 use serde::{Deserialize, Serialize};
@@ -24,7 +23,7 @@ pub struct DeleteResult {
 pub(crate) async fn execute_delete(table: &NativeTable, predicate: &str) -> Result<DeleteResult> {
    table.dataset.ensure_mutable()?;
    let mut dataset = (*table.dataset.get().await?).clone();
-    let delete_result = dataset.delete(predicate).boxed().await?;
+    let delete_result = dataset.delete(predicate).await?;
    let num_deleted_rows = delete_result.num_deleted_rows;
    let version = dataset.version().version;
    table.dataset.update(dataset);
--- a/rust/lancedb/src/table/merge.rs
+++ b/rust/lancedb/src/table/merge.rs
@@ -55,6 +55,7 @@ pub struct MergeInsertBuilder {
    pub(crate) when_not_matched_by_source_delete_filt: Option<String>,
    pub(crate) timeout: Option<Duration>,
    pub(crate) use_index: bool,
+    pub(crate) mem_wal: bool,
 }

 impl MergeInsertBuilder {
@@ -69,6 +70,7 @@ impl MergeInsertBuilder {
            when_not_matched_by_source_delete_filt: None,
            timeout: None,
            use_index: true,
+            mem_wal: false,
        }
    }

@@ -148,13 +150,65 @@ impl MergeInsertBuilder {
        self
    }

+    /// Enables MemWAL (Memory Write-Ahead Log) mode for this merge insert operation.
+    ///
+    /// When enabled, the merge insert will route data through a memory node service
+    /// that buffers writes before flushing to storage. This is only supported for
+    /// remote (LanceDB Cloud) tables.
+    ///
+    /// If not set, defaults to `false`.
+    pub fn mem_wal(&mut self, enabled: bool) -> &mut Self {
+        self.mem_wal = enabled;
+        self
+    }
+
    /// Executes the merge insert operation
    ///
    /// Returns version and statistics about the merge operation including the number of rows
    /// inserted, updated, and deleted.
    pub async fn execute(self, new_data: Box<dyn RecordBatchReader + Send>) -> Result<MergeResult> {
+        // Validate MemWAL constraints before execution
+        if self.mem_wal {
+            self.validate_mem_wal_pattern()?;
+        }
        self.table.clone().merge_insert(self, new_data).await
    }
+
+    /// Validate that the merge insert pattern is supported by MemWAL.
+    ///
+    /// MemWAL only supports the upsert pattern:
+    /// - when_matched_update_all (without filter)
+    /// - when_not_matched_insert_all
+    /// - NO when_not_matched_by_source_delete
+    fn validate_mem_wal_pattern(&self) -> Result<()> {
+        // Must have when_matched_update_all without filter
+        if !self.when_matched_update_all {
+            return Err(Error::InvalidInput {
+                message: "MemWAL requires when_matched_update_all() to be set".to_string(),
+            });
+        }
+        if self.when_matched_update_all_filt.is_some() {
+            return Err(Error::InvalidInput {
+                message: "MemWAL does not support conditional when_matched_update_all (no filter allowed)".to_string(),
+            });
+        }
+
+        // Must have when_not_matched_insert_all
+        if !self.when_not_matched_insert_all {
+            return Err(Error::InvalidInput {
+                message: "MemWAL requires when_not_matched_insert_all() to be set".to_string(),
+            });
+        }
+
+        // Must NOT have when_not_matched_by_source_delete
+        if self.when_not_matched_by_source_delete {
+            return Err(Error::InvalidInput {
+                message: "MemWAL does not support when_not_matched_by_source_delete()".to_string(),
+            });
+        }
+
+        Ok(())
+    }
 }

 /// Internal implementation of the merge insert logic
@@ -165,6 +219,14 @@ pub(crate) async fn execute_merge_insert(
    params: MergeInsertBuilder,
    new_data: Box<dyn RecordBatchReader + Send>,
 ) -> Result<MergeResult> {
+    if params.mem_wal {
+        return Err(Error::NotSupported {
+            message: "MemWAL is not supported for native (local) tables. \
+                      MemWAL is only available for remote (LanceDB Cloud) tables."
+                .to_string(),
+        });
+    }
+
    let dataset = table.dataset.get().await?;
    let mut builder = LanceMergeInsertBuilder::try_new(dataset.clone(), params.on)?;
    match (
@@ -324,4 +386,139 @@ mod tests {
        merge_insert_builder.execute(new_batches).await.unwrap();
        assert_eq!(table.count_rows(None).await.unwrap(), 25);
    }
+
+    #[tokio::test]
+    async fn test_mem_wal_validation_valid_pattern() {
+        let conn = connect("memory://").execute().await.unwrap();
+        let batches = merge_insert_test_batches(0, 0);
+        let table = conn
+            .create_table("mem_wal_test", batches)
+            .execute()
+            .await
+            .unwrap();
+
+        // Valid MemWAL pattern: when_matched_update_all + when_not_matched_insert_all
+        let new_batches = merge_insert_test_batches(5, 1);
+        let mut builder = table.merge_insert(&["i"]);
+        builder.when_matched_update_all(None);
+        builder.when_not_matched_insert_all();
+        builder.mem_wal(true);
+
+        // Should fail because native tables don't support MemWAL, but validation passes
+        let result = builder.execute(new_batches).await;
+        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("MemWAL is not supported for native"),
+            "Expected native table error, got: {}",
+            err
+        );
+    }
+
+    #[tokio::test]
+    async fn test_mem_wal_validation_missing_when_matched() {
+        let conn = connect("memory://").execute().await.unwrap();
+        let batches = merge_insert_test_batches(0, 0);
+        let table = conn
+            .create_table("mem_wal_test2", batches)
+            .execute()
+            .await
+            .unwrap();
+
+        // Missing when_matched_update_all
+        let new_batches = merge_insert_test_batches(5, 1);
+        let mut builder = table.merge_insert(&["i"]);
+        builder.when_not_matched_insert_all();
+        builder.mem_wal(true);
+
+        let result = builder.execute(new_batches).await;
+        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("requires when_matched_update_all"),
+            "Expected validation error, got: {}",
+            err
+        );
+    }
+
+    #[tokio::test]
+    async fn test_mem_wal_validation_missing_when_not_matched() {
+        let conn = connect("memory://").execute().await.unwrap();
+        let batches = merge_insert_test_batches(0, 0);
+        let table = conn
+            .create_table("mem_wal_test3", batches)
+            .execute()
+            .await
+            .unwrap();
+
+        // Missing when_not_matched_insert_all
+        let new_batches = merge_insert_test_batches(5, 1);
+        let mut builder = table.merge_insert(&["i"]);
+        builder.when_matched_update_all(None);
+        builder.mem_wal(true);
+
+        let result = builder.execute(new_batches).await;
+        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("requires when_not_matched_insert_all"),
+            "Expected validation error, got: {}",
+            err
+        );
+    }
+
+    #[tokio::test]
+    async fn test_mem_wal_validation_with_filter() {
+        let conn = connect("memory://").execute().await.unwrap();
+        let batches = merge_insert_test_batches(0, 0);
+        let table = conn
+            .create_table("mem_wal_test4", batches)
+            .execute()
+            .await
+            .unwrap();
+
+        // With conditional filter - not allowed
+        let new_batches = merge_insert_test_batches(5, 1);
+        let mut builder = table.merge_insert(&["i"]);
+        builder.when_matched_update_all(Some("target.age > 0".to_string()));
+        builder.when_not_matched_insert_all();
+        builder.mem_wal(true);
+
+        let result = builder.execute(new_batches).await;
+        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("does not support conditional"),
+            "Expected filter validation error, got: {}",
+            err
+        );
+    }
+
+    #[tokio::test]
+    async fn test_mem_wal_validation_with_delete() {
+        let conn = connect("memory://").execute().await.unwrap();
+        let batches = merge_insert_test_batches(0, 0);
+        let table = conn
+            .create_table("mem_wal_test5", batches)
+            .execute()
+            .await
+            .unwrap();
+
+        // With when_not_matched_by_source_delete - not allowed
+        let new_batches = merge_insert_test_batches(5, 1);
+        let mut builder = table.merge_insert(&["i"]);
+        builder.when_matched_update_all(None);
+        builder.when_not_matched_insert_all();
+        builder.when_not_matched_by_source_delete(None);
+        builder.mem_wal(true);
+
+        let result = builder.execute(new_batches).await;
+        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("does not support when_not_matched_by_source_delete"),
+            "Expected delete validation error, got: {}",
+            err
+        );
+    }
 }
--- a/rust/lancedb/src/table/query.rs
+++ b/rust/lancedb/src/table/query.rs
@@ -40,10 +40,8 @@ pub async fn execute_query(
    query: &AnyQuery,
    options: QueryExecutionOptions,
 ) -> Result<DatasetRecordBatchStream> {
-    // If server-side query is enabled and namespace client is configured, use server-side query execution
-    if table.server_side_query_enabled
-        && let Some(ref namespace_client) = table.namespace_client
-    {
+    // If namespace client is configured, use server-side query execution
+    if let Some(ref namespace_client) = table.namespace_client {
        return execute_namespace_query(table, namespace_client.clone(), query, options).await;
    }
    execute_generic_query(table, query, options).await