Copilot commented on code in PR #9173:
URL: https://github.com/apache/gravitino/pull/9173#discussion_r2598246511
##########
docs/lakehouse-generic-catalog.md:
##########
@@ -0,0 +1,189 @@
+---
+title: "Generic Lakehouse Catalog"
+slug: /lakehouse-generic-catalog
+keywords:
+ - lakehouse
+ - lance
+ - metadata
+ - generic catalog
+ - file system
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Generic Lakehouse Catalog is a Gravitino catalog implementation designed
to seamlessly integrate with lakehouse storage systems built on file
system-based architectures. This catalog enables unified metadata management
for lakehouse tables stored on various storage backends, providing a consistent
interface for data discovery, governance, and access control.
+
+Currently, Gravitino fully supports the **Lance** lakehouse format, with plans
to extend support to additional formats in the future.
+
+### Why Use Generic Lakehouse Catalog?
+
+1. **Unified Metadata Management**: Single source of truth for table metadata
across multiple storage backends
+2. **Multi-Format Support**: Extensible architecture to support various
lakehouse table formats such as Lance, Iceberg, Hudi, etc.
+3. **Storage Flexibility**: Work with any file system - local, or cloud object
stores
+4. **Gravitino Integration**: Leverage Gravitino's metadata management, access
control, lineage tracking, and data discovery
+5. **Easy Migration**: Register existing lakehouse tables without data movement
+
+## Catalog Management
+
+### Capabilities
+
+The Generic Lakehouse Catalog provides comprehensive relational metadata
management capabilities equivalent to standard relational catalogs:
+
+**Supported Operations:**
+- ✅ Create, read, update, and delete catalogs
+- ✅ List all catalogs in a metalake
+- ✅ Manage catalog properties and metadata
+- ✅ Set and modify catalog locations
+- ✅ Configure storage backend credentials
+
+For detailed information on available operations, see [Manage Relational
Metadata Using Gravitino](./manage-relational-metadata-using-gravitino.md).
+
+### Catalog Properties
+
+#### Required Properties
+
+| Property | Description | Example
| Required | Since Version |
+|------------|----------------------------------------------|--------------------------|----------|---------------|
+| `provider` | Catalog provider type |
`lakehouse-generic` | Yes | 1.1.0 |
+| `location` | Root storage path for all schemas and tables |
`s3://buecket/lakehouse` | False | 1.1.0 |
Review Comment:
Typo in example value: "buecket" should be "bucket".
```suggestion
| `location` | Root storage path for all schemas and tables |
`s3://bucket/lakehouse` | False | 1.1.0 |
```
##########
docs/lakehouse-generic-lance-table.md:
##########
@@ -0,0 +1,335 @@
+
+
+---
+title: "Generic lakehouse catalog with Lance"
+slug: /lakehouse-generic-catalog-with-lance
+keywords:
+- lakehouse
+- lance
+- metadata
+- generic catalog
+- file system
+ license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+
+## Overview
+
+This document describes how to use Apache Gravitino to manage a generic
lakehouse catalog using Lance as the underlying table format.
+
+
+## Table Management
+
+### Supported Operations
+
+For Lance tables in a Generic Lakehouse Catalog, the following table
summarizes supported operations:
+
+| Operation | Support Status |
+|-----------|----------------|
+| List | ✅ Full |
+| Load | ✅ Full |
+| Alter | No support now |
+| Create | ✅ Full |
+| Register | ✅ Full |
+| Drop | ✅ Full |
+| Truncate | ✅ Full |
+
+:::note Feature Limitations
+- **Partitioning:** Not currently supported
+- **Sort Orders:** Not currently supported
+- **Distributions:** Not currently supported
+ :::
+
+### Data Type Mappings
+
+Lance uses Apache Arrow for table schemas. The following table shows type
mappings between Gravitino and Arrow:
+
+| Gravitino Type | Arrow Type |
+|----------------------------------|-----------------------------------------|
+| `Struct` | `Struct` |
+| `Map` | `Map` |
+| `List` | `Array` |
+| `Boolean` | `Boolean` |
+| `Byte` | `Int8` |
+| `Short` | `Int16` |
+| `Integer` | `Int32` |
+| `Long` | `Int64` |
+| `Float` | `Float` |
+| `Double` | `Double` |
+| `String` | `Utf8` |
+| `Binary` | `Binary` |
+| `Decimal(p, s)` | `Decimal(p, s)` (128-bit) |
+| `Date` | `Date` |
+| `Timestamp`/`Timestamp(6)` | `TimestampType withoutZone` |
+| `Timestamp(0)` | `TimestampType Second withoutZone` |
+| `Timestamp(3)` | `TimestampType Millisecond withoutZone` |
+| `Timestamp(9)` | `TimestampType Nanosecond withoutZone` |
+| `Timestamp_tz`/`Timestamp_tz(6)` | `TimestampType Microsecond withUtc` |
+| `Timestamp_tz(0)` | `TimestampType Second withUtc` |
+| `Timestamp_tz(3)` | `TimestampType Millisecond withUtc` |
+| `Timestamp_tz(9)` | `TimestampType Nanosecond withUtc` |
+| `Time`/`Time(9)` | `Time Nanosecond` |
+| `Null` | `Null` |
+| `Fixed(n)` | `Fixed-Size Binary(n)` |
+| `Interval_year` | `Interval(YearMonth)` |
+| `Interval_day` | `Duration(Microsecond)` |
+| `External(arrow_field_json_str)` | Any Arrow Field |
+
+### External Type Support
+
+For Arrow types not natively mapped in Gravitino, use the
`External(arrow_field_json_str)` type, which accepts a JSON string
representation of an Arrow `Field`.
+
+**Requirements:**
+- JSON must conform to Apache Arrow [Field
specification](https://github.com/apache/arrow-java/blob/ed81e5981a2bee40584b3a411ed755cb4cc5b91f/vector/src/main/java/org/apache/arrow/vector/types/pojo/Field.java#L80C1-L86C68)
+- `name` attribute must match column name exactly
+- `nullable` attribute must match column nullability
+- `children` array:
+ - Empty for primitive types
+ - Contains child field definitions for complex types (Struct, List)
+
+**Examples:**
+
+| Arrow Type | External Type Definition
|
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Large Utf8` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largeutf8\"},\"children\":[]}")`
|
+| `Large Binary` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largebinary\"},\"children\":[]}")`
|
+| `Large List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largelist\"},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+| `Fixed-Size List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"fixedsizelist\",\"listSize\":10},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+
+### Table Properties
+
+Required and optional properties for tables in a Generic Lakehouse Catalog:
+
+| Property | Description
| Default | Required | Since
Version |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|--------------|---------------|
+| `format` | Table format: `lance`, `iceberg`, etc. (currently
only `lance` is fully supported)
| (none) | Yes | 1.1.0
|
+| `location` | Storage path for table metadata and data, Lance
currently supports: S3, GCS, OSS, AZ, File, Memory and file-object-store.
| (none) | Conditional* |
1.1.0 |
+| `external` | Whether the data directory is an external location.
If it's `true`, dropping a table will only remove metadata in Gravitino and
will not delete the data directory, and purge table will delete both. For a
non-external table, dropping will drop both.
| false | No |
1.1.0 |
+| `lance.creation-mode` | Create mode: for create table, it can be `CREATE`,
`EXIST_OK` or `OVERWRITE`. and it should be `CREATE` and `OVERWRITE` for
registering tables
| `CREATE` | No |
1.1.0 |
Review Comment:
Grammatical error: "and it should be" should be "and it should be `CREATE`
or `OVERWRITE`" for clarity and consistency. The current phrasing is ambiguous
about whether both modes are required or either can be used.
```suggestion
| `lance.creation-mode` | Create mode: for create table, it can be `CREATE`,
`EXIST_OK` or `OVERWRITE`. and it should be `CREATE` or `OVERWRITE` for
registering tables
| `CREATE` | No |
1.1.0 |
```
##########
docs/manage-relational-metadata-using-gravitino.md:
##########
@@ -1007,22 +1011,24 @@ The following table shows the column auto-increment
that Gravitino supports for
| `jdbc-doris` | ✘
|
| `jdbc-oceanbase` |
✔([limitations](./jdbc-oceanbase-catalog.md#table-column-auto-increment))
|
| `jdbc-starrocks` | ✔
|
+| `lakehouse-generic` | ✘
|
#### Table property and type mapping
The following is the table property that Gravitino supports:
-| Catalog provider | Table property
| Type mapping
|
-|---------------------|-----------------------------------------------------------------------------|----------------------------------------------------------------------------|
-| `hive` | [Hive table
property](./apache-hive-catalog.md#table-properties) | [Hive type
mapping](./apache-hive-catalog.md#table-column-types) |
-| `lakehouse-iceberg` | [Iceberg table
property](./lakehouse-iceberg-catalog.md#table-properties) | [Iceberg type
mapping](./lakehouse-iceberg-catalog.md#table-column-types) |
-| `lakehouse-paimon` | [Paimon table
property](./lakehouse-paimon-catalog.md#table-properties) | [Paimon type
mapping](./lakehouse-paimon-catalog.md#table-column-types) |
-| `lakehouse-hudi` | [Hudi table
property](./lakehouse-hudi-catalog.md#table-properties) | [Hudi type
mapping](./lakehouse-hudi-catalog.md#table-column-types) |
-| `jdbc-mysql` | [MySQL table
property](./jdbc-mysql-catalog.md#table-properties) | [MySQL type
mapping](./jdbc-mysql-catalog.md#table-column-types) |
-| `jdbc-postgresql` | [PostgreSQL table
property](./jdbc-postgresql-catalog.md#table-properties) | [PostgreSQL type
mapping](./jdbc-postgresql-catalog.md#table-column-types) |
-| `jdbc-doris` | [Doris table
property](./jdbc-doris-catalog.md#table-properties) | [Doris type
mapping](./jdbc-doris-catalog.md#table-column-types) |
-| `jdbc-oceanbase` | [OceanBase table
property](./jdbc-oceanbase-catalog.md#table-properties) | [OceanBase type
mapping](./jdbc-oceanbase-catalog.md#table-column-types) |
-| `jdbc-starrocks` | [StarRocks table
property](./jdbc-starrocks-catalog.md#table-properties) | [StarRocks type
mapping](./jdbc-starrocks-catalog.md#table-column-types) |
+| Catalog provider | Table property
| Type mapping
|
+|---------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `hive` | [Hive table
property](./apache-hive-catalog.md#table-properties)
| [Hive type
mapping](./apache-hive-catalog.md#table-column-types)
|
+| `lakehouse-iceberg` | [Iceberg table
property](./lakehouse-iceberg-catalog.md#table-properties)
| [Iceberg type
mapping](./lakehouse-iceberg-catalog.md#table-column-types)
|
+| `lakehouse-paimon` | [Paimon table
property](./lakehouse-paimon-catalog.md#table-properties)
| [Paimon type
mapping](./lakehouse-paimon-catalog.md#table-column-types)
|
+| `lakehouse-hudi` | [Hudi table
property](./lakehouse-hudi-catalog.md#table-properties)
| [Hudi type
mapping](./lakehouse-hudi-catalog.md#table-column-types)
|
+| `jdbc-mysql` | [MySQL table
property](./jdbc-mysql-catalog.md#table-properties)
| [MySQL type
mapping](./jdbc-mysql-catalog.md#table-column-types)
|
+| `jdbc-postgresql` | [PostgreSQL table
property](./jdbc-postgresql-catalog.md#table-properties)
| [PostgreSQL type
mapping](./jdbc-postgresql-catalog.md#table-column-types)
|
+| `jdbc-doris` | [Doris table
property](./jdbc-doris-catalog.md#table-properties)
| [Doris type
mapping](./jdbc-doris-catalog.md#table-column-types)
|
+| `jdbc-oceanbase` | [OceanBase table
property](./jdbc-oceanbase-catalog.md#table-properties)
| [OceanBase type
mapping](./jdbc-oceanbase-catalog.md#table-column-types)
|
+| `jdbc-starrocks` | [StarRocks table
property](./jdbc-starrocks-catalog.md#table-properties)
| [StarRocks type
mapping](./jdbc-starrocks-catalog.md#table-column-types)
|
+| `lakehouse-generic` | Lakehouse generic table property depends on specific
table implementation, for Lance table, please refer to
[doc](./lakehouse-generic-lance-table#table-properties), other table format,
please refer to related docs. | Lakehouse generic type mapping. Similar to
table properties, for Lance table, please refer to
[docs](./lakehouse-generic-lance-table#data-type-mappings) |
Review Comment:
Broken documentation links - missing `.md` file extension. The links should
include the file extension for proper navigation:
- `./lakehouse-generic-lance-table#table-properties` should be
`./lakehouse-generic-lance-table.md#table-properties`
- `./lakehouse-generic-lance-table#data-type-mappings` should be
`./lakehouse-generic-lance-table.md#data-type-mappings`
```suggestion
| `lakehouse-generic` | Lakehouse generic table property depends on specific
table implementation, for Lance table, please refer to
[doc](./lakehouse-generic-lance-table.md#table-properties), other table format,
please refer to related docs. | Lakehouse generic type mapping. Similar to
table properties, for Lance table, please refer to
[docs](./lakehouse-generic-lance-table.md#data-type-mappings) |
```
##########
docs/lance-rest-service.md:
##########
@@ -0,0 +1,390 @@
+---
+title: "Lance REST service"
+slug: /lance-rest-service
+keywords:
+ - Lance REST
+ - Lance datasets
+ - REST API
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Lance REST service provides a RESTful interface for managing Lance
datasets through HTTP endpoints. Introduced in Gravitino version 1.1.0, this
service enables seamless interaction with Lance datasets for data operations
and metadata management.
+
+The service implements the [Lance REST API
specification](https://docs.lancedb.com/api-reference/introduction). For
detailed specification documentation, see the [official Lance REST
documentation](https://lance.org/format/namespace/rest/catalog-spec/).
+
+### What is Lance?
+
+[Lance](https://lance.org/format/) is a modern columnar data format designed
for AI/ML workloads. It provides:
+
+- **High-performance vector search**: Native support for similarity search on
high-dimensional embeddings
+- **Columnar storage**: Optimized for analytical queries and machine learning
pipelines
+- **Fast random access**: Efficient row-level operations unlike traditional
columnar formats
+- **Version control**: Built-in dataset versioning and time-travel capabilities
+- **Incremental updates**: Append and update data without full rewrites
+
+### Architecture
+
+The Lance REST service acts as a bridge between Lance datasets and
applications:
+
+```
+┌─────────────────┐
+│ Applications │
+│ (Python/Java) │
+└────────┬────────┘
+ │ HTTP/REST
+ ▼
+┌─────────────────┐
+│ Lance REST │◄──── Gravitino Metalake
+│ Service │ (Metadata Backend)
+└────────┬────────┘
+ │ File System Operations
+ ▼
+┌─────────────────┐
+│ Lance Datasets │
+│ (S3/GCS/Local) │
+└─────────────────┘
+```
+
+**Key Features:**
+- Full compliance with Lance REST API specification
+- Can run standalone or integrated with Gravitino server
+- Support for namespace and table management
+- Index creation and management capabilities (Index operations are not
supported in version 1.1.0)
+- Metadata stored in Gravitino for unified governance
+
+## Supported Operations
+
+The Lance REST service provides comprehensive support for namespace
management, table management, and index operations. The table below lists all
supported operations:
+
+| Operation | Description
| HTTP Method | Endpoint Pattern | Since Version |
+|-------------------|-------------------------------------------------------------------|-------------|-------------------------------------|---------------|
+| CreateNamespace | Create a new Lance namespace
| POST | `/lance/v1/namespace/{id}/create` | 1.1.0 |
+| ListNamespaces | List all namespaces under a parent namespace
| GET | `/lance/v1/namespace/{parent}/list` | 1.1.0 |
+| DescribeNamespace | Retrieve detailed information about a specific namespace
| POST | `/lance/v1/namespace/{id}/describe` | 1.1.0 |
+| DropNamespace | Delete a namespace
| POST | `/lance/v1/namespace/{id}/drop` | 1.1.0 |
+| NamespaceExists | Check whether a namespace exists
| POST | `/lance/v1/namespace/{id}/exists` | 1.1.0 |
+| ListTables | List all tables in a namespace
| GET | `/lance/v1/table/{namespace}/list` | 1.1.0 |
+| CreateTable | Create a new table in a namespace
| POST | `/lance/v1/table/{id}/create` | 1.1.0 |
+| DropTable | Delete a table including both metadata and data
| POST | `/lance/v1/table/{id}/drop` | 1.1.0 |
+| TableExists | Check whether a table exists
| POST | `/lance/v1/table/{id}/exists` | 1.1.0 |
+| RegisterTable | Register an existing Lance table to a namespace
| POST | `/lance/v1/table/{id}/register` | 1.1.0 |
+| DeregisterTable | Unregister a table from a namespace (metadata only, data
remains) | POST | `/lance/v1/table/{id}/deregister` | 1.1.0 |
+
+More details, please refer to the [Lance REST API
specification](https://lance.org/format/namespace/rest/catalog-spec/)
+
+### Operation Details
+
+Some operations have specific behaviors and modes. Below are important details
to consider:
+
+#### Namespace Operations
+
+**CreateNamespace** supports three modes:
+- `create`: Fails if namespace already exists
+- `exist_ok`: Succeeds even if namespace exists
+- `overwrite`: Replaces existing namespace
+
+**DropNamespace** behavior:
+- Recursively deletes all child namespaces and tables
+- Deletes both metadata and Lance data files
+- Operation is irreversible
+
+#### Table Operations
+
+**RegisterTable vs CreateTable**:
+- **RegisterTable**: Links existing Lance datasets into Gravitino catalog
without data movement
+- **CreateTable**: Creates new Lance table with schema and writes data files
+
+**DropTable vs DeregisterTable**:
+- **DropTable**: Permanently deletes metadata and data files from storage
+- **DeregisterTable**: Removes metadata from Gravitino but preserves Lance
data files
+
+
+## Deployment
+
+### Running with Gravitino Server
+
+To enable the Lance REST service within Gravitino server, configure the
following properties in your Gravitino configuration file:
+
+| Configuration Property | Description
| Default Value |
Required | Since Version |
+|-------------------------------------------|------------------------------------------------------------------------------|-------------------------|----------|---------------|
+| `gravitino.auxService.names` | Auxiliary services to run.
Include `lance-rest` to enable Lance REST service | iceberg-rest,lance-rest |
Yes | 0.2.0 |
+| `gravitino.lance-rest.classpath` | Classpath for Lance REST
service, relative to Gravitino home directory | lance-rest-server/libs |
Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Port number for Lance REST
service | 9101 |
Yes | 1.1.0 |
+| `gravitino.lance-rest.host` | Hostname for Lance REST service
| 0.0.0.0 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
(currently only `gravitino` is supported) | gravitino |
Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino-uri` | Gravitino server URI (required
when namespace-backend is `gravitino`) | http://localhost:8090 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
(required when namespace-backend is `gravitino`) | (none)
| Yes | 1.1.0 |
+
+**Example Configuration:**
+
+```properties
+gravitino.auxService.names = lance-rest
+gravitino.lance-rest.httpPort = 9101
+gravitino.lance-rest.host = 0.0.0.0
+gravitino.lance-rest.namespace-backend = gravitino
+gravitino.lance-rest.gravitino.uri = http://localhost:8090
+gravitino.lance-rest.gravitino.metalake-name = my_metalake
+```
+
+### Running Standalone
+
+To run Lance REST service independently without Gravitino server:
+
+```shell
+{GRAVITINO_HOME}/bin/gravitino-lance-rest-server.sh start
+```
+
+Configure the service by editing
`{GRAVITINO_HOME}/conf/gravitino-lance-rest-server.conf` or passing
command-line arguments:
+
+| Configuration Property | Description
| Default Value | Required | Since Version |
+|------------------------------------------------|-----------------------------|-----------------------|----------|---------------|
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
| gravitino | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.uri` | Gravitino server URI
| http://localhost:8090 | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.metalake-name` | Gravitino metalake name
| (none) | Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Service port number
| 9101 | No | 1.1.0 |
+| `gravitino.lance-rest.host` | Service hostname
| 0.0.0.0 | No | 1.1.0 |
+
+:::tip
+In most cases, you only need to configure
`gravitino.lance-rest.gravitino.metalake-name` and other properties can use
their default values.
+:::
+
+
+### Running with Docker
+
+Launch Lance REST service using Docker:
+
+```shell
+docker run -d --name lance-rest-service -p 9101:9101 \
+ -e LANCE_REST_GRAVITINO_URI=http://gravitino-host:8090 \
+ -e LANCE_REST_GRAVITINO_METALAKE_NAME=your_metalake_name \
+ apache/gravitino-lance-rest:latest
+```
+
+Access the service at `http://localhost:9101`.
+
+**Environment Variables:**
+
+| Environment Variable | Configuration Property
| Required | Default Value | Since Version |
+|--------------------------------------|-------------------------------------------|----------|-------------------------|---------------|
+| `LANCE_REST_NAMESPACE_BACKEND` |
`gravitino.lance-rest.namespace-backend` | No | `gravitino`
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_METALAKE_NAME` |
`gravitino.lance-rest.gravitino-metalake` | Yes | (none)
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_URI` | `gravitino.lance-rest.gravitino-uri`
| No | `http://localhost:8090` | 1.1.0 |
+| `LANCE_REST_HOST` | `gravitino.lance-rest.host`
| No | `0.0.0.0` | 1.1.0 |
+| `LANCE_REST_PORT` | `gravitino.lance-rest.httpPort`
| No | `9101` | 1.1.0 |
+
+:::tip Configuration Tips
+- **Required:** Set `LANCE_REST_GRAVITINO_METALAKE_NAME` to your Gravitino
metalake name
+- **Conditional:** Update `LANCE_REST_GRAVITINO_URI` if Gravitino server is
not on `localhost`
+- **Optional:** Other variables can use default values unless you have
specific requirements
+
+
+## Usage Guidelines
+
+When using Lance REST service with Gravitino backend, keep the following
considerations in mind:
+
+### Prerequisites
+- A running Gravitino server with a created metalake
+
+### Namespace Hierarchy
+Gravitino follows a three-level hierarchy: **catalog → schema → table**. When
creating namespaces or tables:
+
+1. **Parent must exist:** Before creating `lance_catalog/schema`, ensure
`lance_catalog` catalog exists in Gravitino metalake.
+2. **Two-level limit:** You can create namespace `lance_catalog/schema`, but
**not** `lance_catalog/schema/sub_schema`.
+3. **Table placement:** Tables can only be created under
`lance_catalog/schema`, not at catalog level.
+
+**Example Hierarchy:**
+```
+metalake
+└── lance_catalog (catalog - create via REST)
+ └── schema (namespace - create via REST)
+ └── table01 (table - create via REST)
+```
+
+### Delimiter Convention
+
+The Lance REST API uses `$` as the default delimiter to separate namespace
levels in URIs. When making HTTP requests:
+
+- **URL Encoding Required**: `$` must be URL-encoded as `%24`
+- **Example**: `lance_catalog$schema$table01` becomes
`lance_catalog%24schema%24table01` in URLs
+
+**Common Delimiters:**
+```
+Namespace path: lance_catalog.schema.table01
+URI representation: lance_catalog$schema$table01
+URL encoded: lance_catalog%24schema%24table01
+```
+
+:::caution Important Limitations
+- Currently supports only **two levels of namespaces** before tables
+- Tables **cannot** be nested deeper than schema level
+- Parent catalog must be created in Gravitino before using Lance REST API
+- Metadata operations require Gravitino server to be available
+- Namespace deletion is recursive and irreversible
+
+## Examples
+
+The following examples demonstrate how to interact with Lance REST service
using different programming languages and tools.
+
+**Prerequisites:**
+- Gravitino server is running with Lance REST service enabled.
+- A metalake has been created in Gravitino.
+
+<Tabs groupId="language" queryString>
+<TabItem value="shell" label="Shell">
+
+```shell
+# Create a catalog-level namespace
+# mode: "create" | "exist_ok" | "overwrite" for create namespace/table; mode:
"create" | "overwrite" for register table
+curl -X POST http://localhost:9101/lance/v1/namespace/lance_catalog/create \
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog"],
+ "mode": "create"
+ }'
+
+# Create a schema namespace
+# Note: %24 is URL-encoded '$' character used as delimiter
+curl -X POST
http://localhost:9101/lance/v1/namespace/lance_catalog%24schema/create \
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog", "schema"],
+ "mode": "create"
+ }'
+
+# Register an existing table
+curl -X POST
http://localhost:9101/lance/v1/table/lance_catalog%24schema%24table01/register \
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog", "schema", "table01"],
+ "location": "/tmp/lance_catalog/schema/table01",
+ "mode": "CREATE"
+ }'
+
+# Create a new empty table
+curl -X POST
http://localhost:9101/lance/v1/table/lance_catalog%24schema%24table02/create-empty
\
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog", "schema", "table02"],
+ "location": "/tmp/lance_catalog/schema/table02",
+ "properties": { "description": "This is table02" }
+ }'
+
+# Create a table with schema, the schema is inferred from the Arrow IPC file
+curl -X POST \
+
"http://localhost:9101/lance/v1/table/lance_catalog%24schema%24table03/create"; \
+ -H 'Content-Type: application/vnd.apache.arrow.stream' \
+ -H "x-lance-table-location: "/tmp/lance_catalog/schema/table04" \
Review Comment:
Incorrect quoting in the curl command header. The header value has
mismatched quotes:
```
-H "x-lance-table-location: "/tmp/lance_catalog/schema/table04"
```
Should be:
```
-H "x-lance-table-location: /tmp/lance_catalog/schema/table04"
```
The inner quotes around the path should be removed to avoid shell parsing
errors.
```suggestion
-H "x-lance-table-location: /tmp/lance_catalog/schema/table04" \
```
##########
docs/lakehouse-generic-lance-table.md:
##########
@@ -0,0 +1,335 @@
+
+
+---
+title: "Generic lakehouse catalog with Lance"
+slug: /lakehouse-generic-catalog-with-lance
+keywords:
+- lakehouse
+- lance
+- metadata
+- generic catalog
+- file system
+ license: "This software is licensed under the Apache License version 2."
Review Comment:
Incorrect YAML frontmatter formatting. The `license` field has incorrect
indentation - it should be at the same level as other frontmatter fields
(`title`, `slug`, `keywords`), not nested under `keywords`.
```suggestion
license: "This software is licensed under the Apache License version 2."
```
##########
docs/lakehouse-generic-lance-table.md:
##########
@@ -0,0 +1,335 @@
+
+
+---
+title: "Generic lakehouse catalog with Lance"
+slug: /lakehouse-generic-catalog-with-lance
+keywords:
+- lakehouse
+- lance
+- metadata
+- generic catalog
+- file system
+ license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+
+## Overview
+
+This document describes how to use Apache Gravitino to manage a generic
lakehouse catalog using Lance as the underlying table format.
+
+
+## Table Management
+
+### Supported Operations
+
+For Lance tables in a Generic Lakehouse Catalog, the following table
summarizes supported operations:
+
+| Operation | Support Status |
+|-----------|----------------|
+| List | ✅ Full |
+| Load | ✅ Full |
+| Alter | No support now |
+| Create | ✅ Full |
+| Register | ✅ Full |
+| Drop | ✅ Full |
+| Truncate | ✅ Full |
+
+:::note Feature Limitations
+- **Partitioning:** Not currently supported
+- **Sort Orders:** Not currently supported
+- **Distributions:** Not currently supported
+ :::
+
+### Data Type Mappings
+
+Lance uses Apache Arrow for table schemas. The following table shows type
mappings between Gravitino and Arrow:
+
+| Gravitino Type | Arrow Type |
+|----------------------------------|-----------------------------------------|
+| `Struct` | `Struct` |
+| `Map` | `Map` |
+| `List` | `Array` |
+| `Boolean` | `Boolean` |
+| `Byte` | `Int8` |
+| `Short` | `Int16` |
+| `Integer` | `Int32` |
+| `Long` | `Int64` |
+| `Float` | `Float` |
+| `Double` | `Double` |
+| `String` | `Utf8` |
+| `Binary` | `Binary` |
+| `Decimal(p, s)` | `Decimal(p, s)` (128-bit) |
+| `Date` | `Date` |
+| `Timestamp`/`Timestamp(6)` | `TimestampType withoutZone` |
+| `Timestamp(0)` | `TimestampType Second withoutZone` |
+| `Timestamp(3)` | `TimestampType Millisecond withoutZone` |
+| `Timestamp(9)` | `TimestampType Nanosecond withoutZone` |
+| `Timestamp_tz`/`Timestamp_tz(6)` | `TimestampType Microsecond withUtc` |
+| `Timestamp_tz(0)` | `TimestampType Second withUtc` |
+| `Timestamp_tz(3)` | `TimestampType Millisecond withUtc` |
+| `Timestamp_tz(9)` | `TimestampType Nanosecond withUtc` |
+| `Time`/`Time(9)` | `Time Nanosecond` |
+| `Null` | `Null` |
+| `Fixed(n)` | `Fixed-Size Binary(n)` |
+| `Interval_year` | `Interval(YearMonth)` |
+| `Interval_day` | `Duration(Microsecond)` |
+| `External(arrow_field_json_str)` | Any Arrow Field |
+
+### External Type Support
+
+For Arrow types not natively mapped in Gravitino, use the
`External(arrow_field_json_str)` type, which accepts a JSON string
representation of an Arrow `Field`.
+
+**Requirements:**
+- JSON must conform to Apache Arrow [Field
specification](https://github.com/apache/arrow-java/blob/ed81e5981a2bee40584b3a411ed755cb4cc5b91f/vector/src/main/java/org/apache/arrow/vector/types/pojo/Field.java#L80C1-L86C68)
+- `name` attribute must match column name exactly
+- `nullable` attribute must match column nullability
+- `children` array:
+ - Empty for primitive types
+ - Contains child field definitions for complex types (Struct, List)
+
+**Examples:**
+
+| Arrow Type | External Type Definition
|
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Large Utf8` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largeutf8\"},\"children\":[]}")`
|
+| `Large Binary` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largebinary\"},\"children\":[]}")`
|
+| `Large List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largelist\"},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+| `Fixed-Size List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"fixedsizelist\",\"listSize\":10},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+
+### Table Properties
+
+Required and optional properties for tables in a Generic Lakehouse Catalog:
+
+| Property | Description
| Default | Required | Since
Version |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|--------------|---------------|
+| `format` | Table format: `lance`, `iceberg`, etc. (currently
only `lance` is fully supported)
| (none) | Yes | 1.1.0
|
+| `location` | Storage path for table metadata and data, Lance
currently supports: S3, GCS, OSS, AZ, File, Memory and file-object-store.
| (none) | Conditional* |
1.1.0 |
+| `external` | Whether the data directory is an external location.
If it's `true`, dropping a table will only remove metadata in Gravitino and
will not delete the data directory, and purge table will delete both. For a
non-external table, dropping will drop both.
| false | No |
1.1.0 |
+| `lance.creation-mode` | Create mode: for create table, it can be `CREATE`,
`EXIST_OK` or `OVERWRITE`. and it should be `CREATE` and `OVERWRITE` for
registering tables
| `CREATE` | No |
1.1.0 |
+| `lance.register` | Whether it is a register table operation. This API
will not create data directory acutally and it's the user responsibility to
create and manage the data directory.
| false | No |
1.1.0 |
Review Comment:
Typo: "acutally" should be "actually".
```suggestion
| `lance.register` | Whether it is a register table operation. This API
will not create data directory actually and it's the user responsibility to
create and manage the data directory.
| false | No |
1.1.0 |
```
##########
docs/lance-rest-service.md:
##########
@@ -0,0 +1,390 @@
+---
+title: "Lance REST service"
+slug: /lance-rest-service
+keywords:
+ - Lance REST
+ - Lance datasets
+ - REST API
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Lance REST service provides a RESTful interface for managing Lance
datasets through HTTP endpoints. Introduced in Gravitino version 1.1.0, this
service enables seamless interaction with Lance datasets for data operations
and metadata management.
+
+The service implements the [Lance REST API
specification](https://docs.lancedb.com/api-reference/introduction). For
detailed specification documentation, see the [official Lance REST
documentation](https://lance.org/format/namespace/rest/catalog-spec/).
+
+### What is Lance?
+
+[Lance](https://lance.org/format/) is a modern columnar data format designed
for AI/ML workloads. It provides:
+
+- **High-performance vector search**: Native support for similarity search on
high-dimensional embeddings
+- **Columnar storage**: Optimized for analytical queries and machine learning
pipelines
+- **Fast random access**: Efficient row-level operations unlike traditional
columnar formats
+- **Version control**: Built-in dataset versioning and time-travel capabilities
+- **Incremental updates**: Append and update data without full rewrites
+
+### Architecture
+
+The Lance REST service acts as a bridge between Lance datasets and
applications:
+
+```
+┌─────────────────┐
+│ Applications │
+│ (Python/Java) │
+└────────┬────────┘
+ │ HTTP/REST
+ ▼
+┌─────────────────┐
+│ Lance REST │◄──── Gravitino Metalake
+│ Service │ (Metadata Backend)
+└────────┬────────┘
+ │ File System Operations
+ ▼
+┌─────────────────┐
+│ Lance Datasets │
+│ (S3/GCS/Local) │
+└─────────────────┘
+```
+
+**Key Features:**
+- Full compliance with Lance REST API specification
+- Can run standalone or integrated with Gravitino server
+- Support for namespace and table management
+- Index creation and management capabilities (Index operations are not
supported in version 1.1.0)
+- Metadata stored in Gravitino for unified governance
+
+## Supported Operations
+
+The Lance REST service provides comprehensive support for namespace
management, table management, and index operations. The table below lists all
supported operations:
+
+| Operation | Description
| HTTP Method | Endpoint Pattern | Since Version |
+|-------------------|-------------------------------------------------------------------|-------------|-------------------------------------|---------------|
+| CreateNamespace | Create a new Lance namespace
| POST | `/lance/v1/namespace/{id}/create` | 1.1.0 |
+| ListNamespaces | List all namespaces under a parent namespace
| GET | `/lance/v1/namespace/{parent}/list` | 1.1.0 |
+| DescribeNamespace | Retrieve detailed information about a specific namespace
| POST | `/lance/v1/namespace/{id}/describe` | 1.1.0 |
+| DropNamespace | Delete a namespace
| POST | `/lance/v1/namespace/{id}/drop` | 1.1.0 |
+| NamespaceExists | Check whether a namespace exists
| POST | `/lance/v1/namespace/{id}/exists` | 1.1.0 |
+| ListTables | List all tables in a namespace
| GET | `/lance/v1/table/{namespace}/list` | 1.1.0 |
+| CreateTable | Create a new table in a namespace
| POST | `/lance/v1/table/{id}/create` | 1.1.0 |
+| DropTable | Delete a table including both metadata and data
| POST | `/lance/v1/table/{id}/drop` | 1.1.0 |
+| TableExists | Check whether a table exists
| POST | `/lance/v1/table/{id}/exists` | 1.1.0 |
+| RegisterTable | Register an existing Lance table to a namespace
| POST | `/lance/v1/table/{id}/register` | 1.1.0 |
+| DeregisterTable | Unregister a table from a namespace (metadata only, data
remains) | POST | `/lance/v1/table/{id}/deregister` | 1.1.0 |
+
+More details, please refer to the [Lance REST API
specification](https://lance.org/format/namespace/rest/catalog-spec/)
+
+### Operation Details
+
+Some operations have specific behaviors and modes. Below are important details
to consider:
+
+#### Namespace Operations
+
+**CreateNamespace** supports three modes:
+- `create`: Fails if namespace already exists
+- `exist_ok`: Succeeds even if namespace exists
+- `overwrite`: Replaces existing namespace
+
+**DropNamespace** behavior:
+- Recursively deletes all child namespaces and tables
+- Deletes both metadata and Lance data files
+- Operation is irreversible
+
+#### Table Operations
+
+**RegisterTable vs CreateTable**:
+- **RegisterTable**: Links existing Lance datasets into Gravitino catalog
without data movement
+- **CreateTable**: Creates new Lance table with schema and writes data files
+
+**DropTable vs DeregisterTable**:
+- **DropTable**: Permanently deletes metadata and data files from storage
+- **DeregisterTable**: Removes metadata from Gravitino but preserves Lance
data files
+
+
+## Deployment
+
+### Running with Gravitino Server
+
+To enable the Lance REST service within Gravitino server, configure the
following properties in your Gravitino configuration file:
+
+| Configuration Property | Description
| Default Value |
Required | Since Version |
+|-------------------------------------------|------------------------------------------------------------------------------|-------------------------|----------|---------------|
+| `gravitino.auxService.names` | Auxiliary services to run.
Include `lance-rest` to enable Lance REST service | iceberg-rest,lance-rest |
Yes | 0.2.0 |
+| `gravitino.lance-rest.classpath` | Classpath for Lance REST
service, relative to Gravitino home directory | lance-rest-server/libs |
Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Port number for Lance REST
service | 9101 |
Yes | 1.1.0 |
+| `gravitino.lance-rest.host` | Hostname for Lance REST service
| 0.0.0.0 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
(currently only `gravitino` is supported) | gravitino |
Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino-uri` | Gravitino server URI (required
when namespace-backend is `gravitino`) | http://localhost:8090 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
(required when namespace-backend is `gravitino`) | (none)
| Yes | 1.1.0 |
+
+**Example Configuration:**
+
+```properties
+gravitino.auxService.names = lance-rest
+gravitino.lance-rest.httpPort = 9101
+gravitino.lance-rest.host = 0.0.0.0
+gravitino.lance-rest.namespace-backend = gravitino
+gravitino.lance-rest.gravitino.uri = http://localhost:8090
+gravitino.lance-rest.gravitino.metalake-name = my_metalake
+```
+
+### Running Standalone
+
+To run Lance REST service independently without Gravitino server:
+
+```shell
+{GRAVITINO_HOME}/bin/gravitino-lance-rest-server.sh start
+```
+
+Configure the service by editing
`{GRAVITINO_HOME}/conf/gravitino-lance-rest-server.conf` or passing
command-line arguments:
+
+| Configuration Property | Description
| Default Value | Required | Since Version |
+|------------------------------------------------|-----------------------------|-----------------------|----------|---------------|
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
| gravitino | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.uri` | Gravitino server URI
| http://localhost:8090 | Yes | 1.1.0 |
Review Comment:
Inconsistent configuration property name. The property is documented as both:
- `gravitino.lance-rest.gravitino.uri` (line 130, 147)
- `gravitino.lance-rest.gravitino-uri` (line 120, 176, and in conf file)
Based on the configuration template file (line 108), the correct property
name should be `gravitino.lance-rest.gravitino-uri` (with hyphen). Please
update lines 130 and 147 to use the correct property name.
##########
docs/lance-rest-service.md:
##########
@@ -0,0 +1,390 @@
+---
+title: "Lance REST service"
+slug: /lance-rest-service
+keywords:
+ - Lance REST
+ - Lance datasets
+ - REST API
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Lance REST service provides a RESTful interface for managing Lance
datasets through HTTP endpoints. Introduced in Gravitino version 1.1.0, this
service enables seamless interaction with Lance datasets for data operations
and metadata management.
+
+The service implements the [Lance REST API
specification](https://docs.lancedb.com/api-reference/introduction). For
detailed specification documentation, see the [official Lance REST
documentation](https://lance.org/format/namespace/rest/catalog-spec/).
+
+### What is Lance?
+
+[Lance](https://lance.org/format/) is a modern columnar data format designed
for AI/ML workloads. It provides:
+
+- **High-performance vector search**: Native support for similarity search on
high-dimensional embeddings
+- **Columnar storage**: Optimized for analytical queries and machine learning
pipelines
+- **Fast random access**: Efficient row-level operations unlike traditional
columnar formats
+- **Version control**: Built-in dataset versioning and time-travel capabilities
+- **Incremental updates**: Append and update data without full rewrites
+
+### Architecture
+
+The Lance REST service acts as a bridge between Lance datasets and
applications:
+
+```
+┌─────────────────┐
+│ Applications │
+│ (Python/Java) │
+└────────┬────────┘
+ │ HTTP/REST
+ ▼
+┌─────────────────┐
+│ Lance REST │◄──── Gravitino Metalake
+│ Service │ (Metadata Backend)
+└────────┬────────┘
+ │ File System Operations
+ ▼
+┌─────────────────┐
+│ Lance Datasets │
+│ (S3/GCS/Local) │
+└─────────────────┘
+```
+
+**Key Features:**
+- Full compliance with Lance REST API specification
+- Can run standalone or integrated with Gravitino server
+- Support for namespace and table management
+- Index creation and management capabilities (Index operations are not
supported in version 1.1.0)
+- Metadata stored in Gravitino for unified governance
+
+## Supported Operations
+
+The Lance REST service provides comprehensive support for namespace
management, table management, and index operations. The table below lists all
supported operations:
+
+| Operation | Description
| HTTP Method | Endpoint Pattern | Since Version |
+|-------------------|-------------------------------------------------------------------|-------------|-------------------------------------|---------------|
+| CreateNamespace | Create a new Lance namespace
| POST | `/lance/v1/namespace/{id}/create` | 1.1.0 |
+| ListNamespaces | List all namespaces under a parent namespace
| GET | `/lance/v1/namespace/{parent}/list` | 1.1.0 |
+| DescribeNamespace | Retrieve detailed information about a specific namespace
| POST | `/lance/v1/namespace/{id}/describe` | 1.1.0 |
+| DropNamespace | Delete a namespace
| POST | `/lance/v1/namespace/{id}/drop` | 1.1.0 |
+| NamespaceExists | Check whether a namespace exists
| POST | `/lance/v1/namespace/{id}/exists` | 1.1.0 |
+| ListTables | List all tables in a namespace
| GET | `/lance/v1/table/{namespace}/list` | 1.1.0 |
+| CreateTable | Create a new table in a namespace
| POST | `/lance/v1/table/{id}/create` | 1.1.0 |
+| DropTable | Delete a table including both metadata and data
| POST | `/lance/v1/table/{id}/drop` | 1.1.0 |
+| TableExists | Check whether a table exists
| POST | `/lance/v1/table/{id}/exists` | 1.1.0 |
+| RegisterTable | Register an existing Lance table to a namespace
| POST | `/lance/v1/table/{id}/register` | 1.1.0 |
+| DeregisterTable | Unregister a table from a namespace (metadata only, data
remains) | POST | `/lance/v1/table/{id}/deregister` | 1.1.0 |
+
+More details, please refer to the [Lance REST API
specification](https://lance.org/format/namespace/rest/catalog-spec/)
+
+### Operation Details
+
+Some operations have specific behaviors and modes. Below are important details
to consider:
+
+#### Namespace Operations
+
+**CreateNamespace** supports three modes:
+- `create`: Fails if namespace already exists
+- `exist_ok`: Succeeds even if namespace exists
+- `overwrite`: Replaces existing namespace
+
+**DropNamespace** behavior:
+- Recursively deletes all child namespaces and tables
+- Deletes both metadata and Lance data files
+- Operation is irreversible
+
+#### Table Operations
+
+**RegisterTable vs CreateTable**:
+- **RegisterTable**: Links existing Lance datasets into Gravitino catalog
without data movement
+- **CreateTable**: Creates new Lance table with schema and writes data files
+
+**DropTable vs DeregisterTable**:
+- **DropTable**: Permanently deletes metadata and data files from storage
+- **DeregisterTable**: Removes metadata from Gravitino but preserves Lance
data files
+
+
+## Deployment
+
+### Running with Gravitino Server
+
+To enable the Lance REST service within Gravitino server, configure the
following properties in your Gravitino configuration file:
+
+| Configuration Property | Description
| Default Value |
Required | Since Version |
+|-------------------------------------------|------------------------------------------------------------------------------|-------------------------|----------|---------------|
+| `gravitino.auxService.names` | Auxiliary services to run.
Include `lance-rest` to enable Lance REST service | iceberg-rest,lance-rest |
Yes | 0.2.0 |
+| `gravitino.lance-rest.classpath` | Classpath for Lance REST
service, relative to Gravitino home directory | lance-rest-server/libs |
Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Port number for Lance REST
service | 9101 |
Yes | 1.1.0 |
+| `gravitino.lance-rest.host` | Hostname for Lance REST service
| 0.0.0.0 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
(currently only `gravitino` is supported) | gravitino |
Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino-uri` | Gravitino server URI (required
when namespace-backend is `gravitino`) | http://localhost:8090 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
(required when namespace-backend is `gravitino`) | (none)
| Yes | 1.1.0 |
+
+**Example Configuration:**
+
+```properties
+gravitino.auxService.names = lance-rest
+gravitino.lance-rest.httpPort = 9101
+gravitino.lance-rest.host = 0.0.0.0
+gravitino.lance-rest.namespace-backend = gravitino
+gravitino.lance-rest.gravitino.uri = http://localhost:8090
+gravitino.lance-rest.gravitino.metalake-name = my_metalake
+```
+
+### Running Standalone
+
+To run Lance REST service independently without Gravitino server:
+
+```shell
+{GRAVITINO_HOME}/bin/gravitino-lance-rest-server.sh start
+```
+
+Configure the service by editing
`{GRAVITINO_HOME}/conf/gravitino-lance-rest-server.conf` or passing
command-line arguments:
+
+| Configuration Property | Description
| Default Value | Required | Since Version |
+|------------------------------------------------|-----------------------------|-----------------------|----------|---------------|
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
| gravitino | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.uri` | Gravitino server URI
| http://localhost:8090 | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.metalake-name` | Gravitino metalake name
| (none) | Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Service port number
| 9101 | No | 1.1.0 |
+| `gravitino.lance-rest.host` | Service hostname
| 0.0.0.0 | No | 1.1.0 |
+
+:::tip
+In most cases, you only need to configure
`gravitino.lance-rest.gravitino.metalake-name` and other properties can use
their default values.
Review Comment:
Inconsistent configuration property name. The property is documented as both:
- `gravitino.lance-rest.gravitino.metalake-name` (line 131, 148, 153)
- `gravitino.lance-rest.gravitino-metalake` (line 121, 175, and in conf file)
Based on the configuration template file change in this PR (line 110), the
correct property name should be `gravitino.lance-rest.gravitino-metalake` (with
hyphen, no dot before metalake). Please update lines 131, 148, and 153 to use
the correct property name.
```suggestion
| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
| (none) | Yes | 1.1.0 |
| `gravitino.lance-rest.httpPort` | Service port number
| 9101 | No | 1.1.0 |
| `gravitino.lance-rest.host` | Service hostname
| 0.0.0.0 | No | 1.1.0 |
:::tip
In most cases, you only need to configure
`gravitino.lance-rest.gravitino-metalake` and other properties can use their
default values.
```
##########
docs/manage-relational-metadata-using-gravitino.md:
##########
@@ -979,17 +982,18 @@ When defining a table column, you can specify a
[literal](./expression.md#litera
The following is a table of the column default value that Gravitino supports
for different catalogs:
-| Catalog provider | Supported default value |
-|---------------------|-------------------------|
-| `hive` | ✘ |
-| `lakehouse-iceberg` | ✘ |
-| `lakehouse-paimon` | ✘ |
-| `lakehouse-hudi` | ✘ |
-| `jdbc-mysql` | ✔ |
-| `jdbc-postgresql` | ✔ |
-| `jdbc-doris` | ✔ |
-| `jdbc-oceanbase` | ✔ |
-| `jdbc-starrocks` | ✔ |
+| Catalog provider | Supported default value |
+|----------------------|-------------------------|
+| `hive` | ✘ |
+| `lakehouse-iceberg` | ✘ |
+| `lakehouse-paimon` | ✘ |
+| `lakehouse-hudi` | ✘ |
+| `jdbc-mysql` | ✔ |
+| `jdbc-postgresql` | ✔ |
+| `jdbc-doris` | ✔ |
+| `jdbc-oceanbase` | ✔ |
+| `jdbc-starrocks` | ✔ |
+| `lakehouse-generic` | ✘ |
Review Comment:
Table formatting issue: Extra space before the pipe character. Should be `|`
not ` |` at the start of the line for consistent table formatting.
##########
docs/manage-relational-metadata-using-gravitino.md:
##########
@@ -506,6 +508,7 @@ Currently, Gravitino supports the following schema property:
| `jdbc-doris` | [Doris schema
property](./jdbc-doris-catalog.md#schema-properties) |
| `jdbc-oceanbase` | [OceanBase schema
property](./jdbc-oceanbase-catalog.md#schema-properties) |
| `jdbc-starrocks` | [StarRocks schema
property](./jdbc-starrocks-catalog.md#schema-properties) |
+| `lakehouse-genric` | [Lakehouse generic schema
property](./lakehouse-generic-catalog.md#schema-properties) |
Review Comment:
Typo in catalog provider name: "lakehouse-genric" should be
"lakehouse-generic" to match the correct spelling used elsewhere in the
documentation.
```suggestion
| `lakehouse-generic` | [Lakehouse generic schema
property](./lakehouse-generic-catalog.md#schema-properties) |
```
##########
docs/lance-rest-service.md:
##########
@@ -0,0 +1,390 @@
+---
+title: "Lance REST service"
+slug: /lance-rest-service
+keywords:
+ - Lance REST
+ - Lance datasets
+ - REST API
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Lance REST service provides a RESTful interface for managing Lance
datasets through HTTP endpoints. Introduced in Gravitino version 1.1.0, this
service enables seamless interaction with Lance datasets for data operations
and metadata management.
+
+The service implements the [Lance REST API
specification](https://docs.lancedb.com/api-reference/introduction). For
detailed specification documentation, see the [official Lance REST
documentation](https://lance.org/format/namespace/rest/catalog-spec/).
+
+### What is Lance?
+
+[Lance](https://lance.org/format/) is a modern columnar data format designed
for AI/ML workloads. It provides:
+
+- **High-performance vector search**: Native support for similarity search on
high-dimensional embeddings
+- **Columnar storage**: Optimized for analytical queries and machine learning
pipelines
+- **Fast random access**: Efficient row-level operations unlike traditional
columnar formats
+- **Version control**: Built-in dataset versioning and time-travel capabilities
+- **Incremental updates**: Append and update data without full rewrites
+
+### Architecture
+
+The Lance REST service acts as a bridge between Lance datasets and
applications:
+
+```
+┌─────────────────┐
+│ Applications │
+│ (Python/Java) │
+└────────┬────────┘
+ │ HTTP/REST
+ ▼
+┌─────────────────┐
+│ Lance REST │◄──── Gravitino Metalake
+│ Service │ (Metadata Backend)
+└────────┬────────┘
+ │ File System Operations
+ ▼
+┌─────────────────┐
+│ Lance Datasets │
+│ (S3/GCS/Local) │
+└─────────────────┘
+```
+
+**Key Features:**
+- Full compliance with Lance REST API specification
+- Can run standalone or integrated with Gravitino server
+- Support for namespace and table management
+- Index creation and management capabilities (Index operations are not
supported in version 1.1.0)
+- Metadata stored in Gravitino for unified governance
+
+## Supported Operations
+
+The Lance REST service provides comprehensive support for namespace
management, table management, and index operations. The table below lists all
supported operations:
+
+| Operation | Description
| HTTP Method | Endpoint Pattern | Since Version |
+|-------------------|-------------------------------------------------------------------|-------------|-------------------------------------|---------------|
+| CreateNamespace | Create a new Lance namespace
| POST | `/lance/v1/namespace/{id}/create` | 1.1.0 |
+| ListNamespaces | List all namespaces under a parent namespace
| GET | `/lance/v1/namespace/{parent}/list` | 1.1.0 |
+| DescribeNamespace | Retrieve detailed information about a specific namespace
| POST | `/lance/v1/namespace/{id}/describe` | 1.1.0 |
+| DropNamespace | Delete a namespace
| POST | `/lance/v1/namespace/{id}/drop` | 1.1.0 |
+| NamespaceExists | Check whether a namespace exists
| POST | `/lance/v1/namespace/{id}/exists` | 1.1.0 |
+| ListTables | List all tables in a namespace
| GET | `/lance/v1/table/{namespace}/list` | 1.1.0 |
+| CreateTable | Create a new table in a namespace
| POST | `/lance/v1/table/{id}/create` | 1.1.0 |
+| DropTable | Delete a table including both metadata and data
| POST | `/lance/v1/table/{id}/drop` | 1.1.0 |
+| TableExists | Check whether a table exists
| POST | `/lance/v1/table/{id}/exists` | 1.1.0 |
+| RegisterTable | Register an existing Lance table to a namespace
| POST | `/lance/v1/table/{id}/register` | 1.1.0 |
+| DeregisterTable | Unregister a table from a namespace (metadata only, data
remains) | POST | `/lance/v1/table/{id}/deregister` | 1.1.0 |
+
+More details, please refer to the [Lance REST API
specification](https://lance.org/format/namespace/rest/catalog-spec/)
+
+### Operation Details
+
+Some operations have specific behaviors and modes. Below are important details
to consider:
+
+#### Namespace Operations
+
+**CreateNamespace** supports three modes:
+- `create`: Fails if namespace already exists
+- `exist_ok`: Succeeds even if namespace exists
+- `overwrite`: Replaces existing namespace
+
+**DropNamespace** behavior:
+- Recursively deletes all child namespaces and tables
+- Deletes both metadata and Lance data files
+- Operation is irreversible
+
+#### Table Operations
+
+**RegisterTable vs CreateTable**:
+- **RegisterTable**: Links existing Lance datasets into Gravitino catalog
without data movement
+- **CreateTable**: Creates new Lance table with schema and writes data files
+
+**DropTable vs DeregisterTable**:
+- **DropTable**: Permanently deletes metadata and data files from storage
+- **DeregisterTable**: Removes metadata from Gravitino but preserves Lance
data files
+
+
+## Deployment
+
+### Running with Gravitino Server
+
+To enable the Lance REST service within Gravitino server, configure the
following properties in your Gravitino configuration file:
+
+| Configuration Property | Description
| Default Value |
Required | Since Version |
+|-------------------------------------------|------------------------------------------------------------------------------|-------------------------|----------|---------------|
+| `gravitino.auxService.names` | Auxiliary services to run.
Include `lance-rest` to enable Lance REST service | iceberg-rest,lance-rest |
Yes | 0.2.0 |
+| `gravitino.lance-rest.classpath` | Classpath for Lance REST
service, relative to Gravitino home directory | lance-rest-server/libs |
Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Port number for Lance REST
service | 9101 |
Yes | 1.1.0 |
+| `gravitino.lance-rest.host` | Hostname for Lance REST service
| 0.0.0.0 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
(currently only `gravitino` is supported) | gravitino |
Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino-uri` | Gravitino server URI (required
when namespace-backend is `gravitino`) | http://localhost:8090 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
(required when namespace-backend is `gravitino`) | (none)
| Yes | 1.1.0 |
+
+**Example Configuration:**
+
+```properties
+gravitino.auxService.names = lance-rest
+gravitino.lance-rest.httpPort = 9101
+gravitino.lance-rest.host = 0.0.0.0
+gravitino.lance-rest.namespace-backend = gravitino
+gravitino.lance-rest.gravitino.uri = http://localhost:8090
+gravitino.lance-rest.gravitino.metalake-name = my_metalake
+```
+
+### Running Standalone
+
+To run Lance REST service independently without Gravitino server:
+
+```shell
+{GRAVITINO_HOME}/bin/gravitino-lance-rest-server.sh start
+```
+
+Configure the service by editing
`{GRAVITINO_HOME}/conf/gravitino-lance-rest-server.conf` or passing
command-line arguments:
+
+| Configuration Property | Description
| Default Value | Required | Since Version |
+|------------------------------------------------|-----------------------------|-----------------------|----------|---------------|
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
| gravitino | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.uri` | Gravitino server URI
| http://localhost:8090 | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.metalake-name` | Gravitino metalake name
| (none) | Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Service port number
| 9101 | No | 1.1.0 |
+| `gravitino.lance-rest.host` | Service hostname
| 0.0.0.0 | No | 1.1.0 |
+
+:::tip
+In most cases, you only need to configure
`gravitino.lance-rest.gravitino.metalake-name` and other properties can use
their default values.
+:::
+
+
+### Running with Docker
+
+Launch Lance REST service using Docker:
+
+```shell
+docker run -d --name lance-rest-service -p 9101:9101 \
+ -e LANCE_REST_GRAVITINO_URI=http://gravitino-host:8090 \
+ -e LANCE_REST_GRAVITINO_METALAKE_NAME=your_metalake_name \
+ apache/gravitino-lance-rest:latest
+```
+
+Access the service at `http://localhost:9101`.
+
+**Environment Variables:**
+
+| Environment Variable | Configuration Property
| Required | Default Value | Since Version |
+|--------------------------------------|-------------------------------------------|----------|-------------------------|---------------|
+| `LANCE_REST_NAMESPACE_BACKEND` |
`gravitino.lance-rest.namespace-backend` | No | `gravitino`
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_METALAKE_NAME` |
`gravitino.lance-rest.gravitino-metalake` | Yes | (none)
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_URI` | `gravitino.lance-rest.gravitino-uri`
| No | `http://localhost:8090` | 1.1.0 |
+| `LANCE_REST_HOST` | `gravitino.lance-rest.host`
| No | `0.0.0.0` | 1.1.0 |
+| `LANCE_REST_PORT` | `gravitino.lance-rest.httpPort`
| No | `9101` | 1.1.0 |
+
+:::tip Configuration Tips
+- **Required:** Set `LANCE_REST_GRAVITINO_METALAKE_NAME` to your Gravitino
metalake name
+- **Conditional:** Update `LANCE_REST_GRAVITINO_URI` if Gravitino server is
not on `localhost`
+- **Optional:** Other variables can use default values unless you have
specific requirements
+
Review Comment:
Missing closing tag for the tip admonition block. The `:::tip Configuration
Tips` block (line 180) is not properly closed with `:::` before the next
section starts.
```suggestion
:::
```
##########
docs/lance-rest-service.md:
##########
@@ -0,0 +1,390 @@
+---
+title: "Lance REST service"
+slug: /lance-rest-service
+keywords:
+ - Lance REST
+ - Lance datasets
+ - REST API
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Lance REST service provides a RESTful interface for managing Lance
datasets through HTTP endpoints. Introduced in Gravitino version 1.1.0, this
service enables seamless interaction with Lance datasets for data operations
and metadata management.
+
+The service implements the [Lance REST API
specification](https://docs.lancedb.com/api-reference/introduction). For
detailed specification documentation, see the [official Lance REST
documentation](https://lance.org/format/namespace/rest/catalog-spec/).
+
+### What is Lance?
+
+[Lance](https://lance.org/format/) is a modern columnar data format designed
for AI/ML workloads. It provides:
+
+- **High-performance vector search**: Native support for similarity search on
high-dimensional embeddings
+- **Columnar storage**: Optimized for analytical queries and machine learning
pipelines
+- **Fast random access**: Efficient row-level operations unlike traditional
columnar formats
+- **Version control**: Built-in dataset versioning and time-travel capabilities
+- **Incremental updates**: Append and update data without full rewrites
+
+### Architecture
+
+The Lance REST service acts as a bridge between Lance datasets and
applications:
+
+```
+┌─────────────────┐
+│ Applications │
+│ (Python/Java) │
+└────────┬────────┘
+ │ HTTP/REST
+ ▼
+┌─────────────────┐
+│ Lance REST │◄──── Gravitino Metalake
+│ Service │ (Metadata Backend)
+└────────┬────────┘
+ │ File System Operations
+ ▼
+┌─────────────────┐
+│ Lance Datasets │
+│ (S3/GCS/Local) │
+└─────────────────┘
+```
+
+**Key Features:**
+- Full compliance with Lance REST API specification
+- Can run standalone or integrated with Gravitino server
+- Support for namespace and table management
+- Index creation and management capabilities (Index operations are not
supported in version 1.1.0)
+- Metadata stored in Gravitino for unified governance
+
+## Supported Operations
+
+The Lance REST service provides comprehensive support for namespace
management, table management, and index operations. The table below lists all
supported operations:
+
+| Operation | Description
| HTTP Method | Endpoint Pattern | Since Version |
+|-------------------|-------------------------------------------------------------------|-------------|-------------------------------------|---------------|
+| CreateNamespace | Create a new Lance namespace
| POST | `/lance/v1/namespace/{id}/create` | 1.1.0 |
+| ListNamespaces | List all namespaces under a parent namespace
| GET | `/lance/v1/namespace/{parent}/list` | 1.1.0 |
+| DescribeNamespace | Retrieve detailed information about a specific namespace
| POST | `/lance/v1/namespace/{id}/describe` | 1.1.0 |
+| DropNamespace | Delete a namespace
| POST | `/lance/v1/namespace/{id}/drop` | 1.1.0 |
+| NamespaceExists | Check whether a namespace exists
| POST | `/lance/v1/namespace/{id}/exists` | 1.1.0 |
+| ListTables | List all tables in a namespace
| GET | `/lance/v1/table/{namespace}/list` | 1.1.0 |
+| CreateTable | Create a new table in a namespace
| POST | `/lance/v1/table/{id}/create` | 1.1.0 |
+| DropTable | Delete a table including both metadata and data
| POST | `/lance/v1/table/{id}/drop` | 1.1.0 |
+| TableExists | Check whether a table exists
| POST | `/lance/v1/table/{id}/exists` | 1.1.0 |
+| RegisterTable | Register an existing Lance table to a namespace
| POST | `/lance/v1/table/{id}/register` | 1.1.0 |
+| DeregisterTable | Unregister a table from a namespace (metadata only, data
remains) | POST | `/lance/v1/table/{id}/deregister` | 1.1.0 |
+
+More details, please refer to the [Lance REST API
specification](https://lance.org/format/namespace/rest/catalog-spec/)
+
+### Operation Details
+
+Some operations have specific behaviors and modes. Below are important details
to consider:
+
+#### Namespace Operations
+
+**CreateNamespace** supports three modes:
+- `create`: Fails if namespace already exists
+- `exist_ok`: Succeeds even if namespace exists
+- `overwrite`: Replaces existing namespace
+
+**DropNamespace** behavior:
+- Recursively deletes all child namespaces and tables
+- Deletes both metadata and Lance data files
+- Operation is irreversible
+
+#### Table Operations
+
+**RegisterTable vs CreateTable**:
+- **RegisterTable**: Links existing Lance datasets into Gravitino catalog
without data movement
+- **CreateTable**: Creates new Lance table with schema and writes data files
+
+**DropTable vs DeregisterTable**:
+- **DropTable**: Permanently deletes metadata and data files from storage
+- **DeregisterTable**: Removes metadata from Gravitino but preserves Lance
data files
+
+
+## Deployment
+
+### Running with Gravitino Server
+
+To enable the Lance REST service within Gravitino server, configure the
following properties in your Gravitino configuration file:
+
+| Configuration Property | Description
| Default Value |
Required | Since Version |
+|-------------------------------------------|------------------------------------------------------------------------------|-------------------------|----------|---------------|
+| `gravitino.auxService.names` | Auxiliary services to run.
Include `lance-rest` to enable Lance REST service | iceberg-rest,lance-rest |
Yes | 0.2.0 |
+| `gravitino.lance-rest.classpath` | Classpath for Lance REST
service, relative to Gravitino home directory | lance-rest-server/libs |
Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Port number for Lance REST
service | 9101 |
Yes | 1.1.0 |
+| `gravitino.lance-rest.host` | Hostname for Lance REST service
| 0.0.0.0 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
(currently only `gravitino` is supported) | gravitino |
Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino-uri` | Gravitino server URI (required
when namespace-backend is `gravitino`) | http://localhost:8090 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
(required when namespace-backend is `gravitino`) | (none)
| Yes | 1.1.0 |
+
+**Example Configuration:**
+
+```properties
+gravitino.auxService.names = lance-rest
+gravitino.lance-rest.httpPort = 9101
+gravitino.lance-rest.host = 0.0.0.0
+gravitino.lance-rest.namespace-backend = gravitino
+gravitino.lance-rest.gravitino.uri = http://localhost:8090
+gravitino.lance-rest.gravitino.metalake-name = my_metalake
+```
+
+### Running Standalone
+
+To run Lance REST service independently without Gravitino server:
+
+```shell
+{GRAVITINO_HOME}/bin/gravitino-lance-rest-server.sh start
+```
+
+Configure the service by editing
`{GRAVITINO_HOME}/conf/gravitino-lance-rest-server.conf` or passing
command-line arguments:
+
+| Configuration Property | Description
| Default Value | Required | Since Version |
+|------------------------------------------------|-----------------------------|-----------------------|----------|---------------|
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
| gravitino | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.uri` | Gravitino server URI
| http://localhost:8090 | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.metalake-name` | Gravitino metalake name
| (none) | Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Service port number
| 9101 | No | 1.1.0 |
+| `gravitino.lance-rest.host` | Service hostname
| 0.0.0.0 | No | 1.1.0 |
+
+:::tip
+In most cases, you only need to configure
`gravitino.lance-rest.gravitino.metalake-name` and other properties can use
their default values.
+:::
+
+
+### Running with Docker
+
+Launch Lance REST service using Docker:
+
+```shell
+docker run -d --name lance-rest-service -p 9101:9101 \
+ -e LANCE_REST_GRAVITINO_URI=http://gravitino-host:8090 \
+ -e LANCE_REST_GRAVITINO_METALAKE_NAME=your_metalake_name \
+ apache/gravitino-lance-rest:latest
+```
+
+Access the service at `http://localhost:9101`.
+
+**Environment Variables:**
+
+| Environment Variable | Configuration Property
| Required | Default Value | Since Version |
+|--------------------------------------|-------------------------------------------|----------|-------------------------|---------------|
+| `LANCE_REST_NAMESPACE_BACKEND` |
`gravitino.lance-rest.namespace-backend` | No | `gravitino`
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_METALAKE_NAME` |
`gravitino.lance-rest.gravitino-metalake` | Yes | (none)
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_URI` | `gravitino.lance-rest.gravitino-uri`
| No | `http://localhost:8090` | 1.1.0 |
+| `LANCE_REST_HOST` | `gravitino.lance-rest.host`
| No | `0.0.0.0` | 1.1.0 |
+| `LANCE_REST_PORT` | `gravitino.lance-rest.httpPort`
| No | `9101` | 1.1.0 |
+
+:::tip Configuration Tips
+- **Required:** Set `LANCE_REST_GRAVITINO_METALAKE_NAME` to your Gravitino
metalake name
+- **Conditional:** Update `LANCE_REST_GRAVITINO_URI` if Gravitino server is
not on `localhost`
+- **Optional:** Other variables can use default values unless you have
specific requirements
+
+
+## Usage Guidelines
+
+When using Lance REST service with Gravitino backend, keep the following
considerations in mind:
+
+### Prerequisites
+- A running Gravitino server with a created metalake
+
+### Namespace Hierarchy
+Gravitino follows a three-level hierarchy: **catalog → schema → table**. When
creating namespaces or tables:
+
+1. **Parent must exist:** Before creating `lance_catalog/schema`, ensure
`lance_catalog` catalog exists in Gravitino metalake.
+2. **Two-level limit:** You can create namespace `lance_catalog/schema`, but
**not** `lance_catalog/schema/sub_schema`.
+3. **Table placement:** Tables can only be created under
`lance_catalog/schema`, not at catalog level.
+
+**Example Hierarchy:**
+```
+metalake
+└── lance_catalog (catalog - create via REST)
+ └── schema (namespace - create via REST)
+ └── table01 (table - create via REST)
+```
+
+### Delimiter Convention
+
+The Lance REST API uses `$` as the default delimiter to separate namespace
levels in URIs. When making HTTP requests:
+
+- **URL Encoding Required**: `$` must be URL-encoded as `%24`
+- **Example**: `lance_catalog$schema$table01` becomes
`lance_catalog%24schema%24table01` in URLs
+
+**Common Delimiters:**
+```
+Namespace path: lance_catalog.schema.table01
+URI representation: lance_catalog$schema$table01
+URL encoded: lance_catalog%24schema%24table01
+```
+
+:::caution Important Limitations
+- Currently supports only **two levels of namespaces** before tables
+- Tables **cannot** be nested deeper than schema level
+- Parent catalog must be created in Gravitino before using Lance REST API
+- Metadata operations require Gravitino server to be available
+- Namespace deletion is recursive and irreversible
+
+## Examples
+
+The following examples demonstrate how to interact with Lance REST service
using different programming languages and tools.
+
+**Prerequisites:**
+- Gravitino server is running with Lance REST service enabled.
+- A metalake has been created in Gravitino.
+
+<Tabs groupId="language" queryString>
+<TabItem value="shell" label="Shell">
+
+```shell
+# Create a catalog-level namespace
+# mode: "create" | "exist_ok" | "overwrite" for create namespace/table; mode:
"create" | "overwrite" for register table
+curl -X POST http://localhost:9101/lance/v1/namespace/lance_catalog/create \
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog"],
+ "mode": "create"
+ }'
+
+# Create a schema namespace
+# Note: %24 is URL-encoded '$' character used as delimiter
+curl -X POST
http://localhost:9101/lance/v1/namespace/lance_catalog%24schema/create \
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog", "schema"],
+ "mode": "create"
+ }'
+
+# Register an existing table
+curl -X POST
http://localhost:9101/lance/v1/table/lance_catalog%24schema%24table01/register \
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog", "schema", "table01"],
+ "location": "/tmp/lance_catalog/schema/table01",
+ "mode": "CREATE"
+ }'
+
+# Create a new empty table
+curl -X POST
http://localhost:9101/lance/v1/table/lance_catalog%24schema%24table02/create-empty
\
+ -H 'Content-Type: application/json' \
+ -d '{
+ "id": ["lance_catalog", "schema", "table02"],
+ "location": "/tmp/lance_catalog/schema/table02",
+ "properties": { "description": "This is table02" }
+ }'
+
+# Create a table with schema, the schema is inferred from the Arrow IPC file
+curl -X POST \
+
"http://localhost:9101/lance/v1/table/lance_catalog%24schema%24table03/create"; \
+ -H 'Content-Type: application/vnd.apache.arrow.stream' \
+ -H "x-lance-table-location: "/tmp/lance_catalog/schema/table04" \
Review Comment:
Inconsistent table naming in the comment and the header. The comment states
"table03" but the header value shows "table04":
- Comment: `# Create a table with schema, the schema is inferred from the
Arrow IPC file`
- Endpoint: `/table/lance_catalog%24schema%24table03/create`
- Header: `x-lance-table-location: "/tmp/lance_catalog/schema/table04"`
The location path should match the table name. Change "table04" to "table03"
in the x-lance-table-location header.
```suggestion
-H "x-lance-table-location: "/tmp/lance_catalog/schema/table03" \
```
##########
docs/lakehouse-generic-lance-table.md:
##########
@@ -0,0 +1,335 @@
+
+
+---
+title: "Generic lakehouse catalog with Lance"
+slug: /lakehouse-generic-catalog-with-lance
+keywords:
+- lakehouse
+- lance
+- metadata
+- generic catalog
+- file system
+ license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+
+## Overview
+
+This document describes how to use Apache Gravitino to manage a generic
lakehouse catalog using Lance as the underlying table format.
+
+
+## Table Management
+
+### Supported Operations
+
+For Lance tables in a Generic Lakehouse Catalog, the following table
summarizes supported operations:
+
+| Operation | Support Status |
+|-----------|----------------|
+| List | ✅ Full |
+| Load | ✅ Full |
+| Alter | No support now |
+| Create | ✅ Full |
+| Register | ✅ Full |
+| Drop | ✅ Full |
+| Truncate | ✅ Full |
+
+:::note Feature Limitations
+- **Partitioning:** Not currently supported
+- **Sort Orders:** Not currently supported
+- **Distributions:** Not currently supported
+ :::
+
+### Data Type Mappings
+
+Lance uses Apache Arrow for table schemas. The following table shows type
mappings between Gravitino and Arrow:
+
+| Gravitino Type | Arrow Type |
+|----------------------------------|-----------------------------------------|
+| `Struct` | `Struct` |
+| `Map` | `Map` |
+| `List` | `Array` |
+| `Boolean` | `Boolean` |
+| `Byte` | `Int8` |
+| `Short` | `Int16` |
+| `Integer` | `Int32` |
+| `Long` | `Int64` |
+| `Float` | `Float` |
+| `Double` | `Double` |
+| `String` | `Utf8` |
+| `Binary` | `Binary` |
+| `Decimal(p, s)` | `Decimal(p, s)` (128-bit) |
+| `Date` | `Date` |
+| `Timestamp`/`Timestamp(6)` | `TimestampType withoutZone` |
+| `Timestamp(0)` | `TimestampType Second withoutZone` |
+| `Timestamp(3)` | `TimestampType Millisecond withoutZone` |
+| `Timestamp(9)` | `TimestampType Nanosecond withoutZone` |
+| `Timestamp_tz`/`Timestamp_tz(6)` | `TimestampType Microsecond withUtc` |
+| `Timestamp_tz(0)` | `TimestampType Second withUtc` |
+| `Timestamp_tz(3)` | `TimestampType Millisecond withUtc` |
+| `Timestamp_tz(9)` | `TimestampType Nanosecond withUtc` |
+| `Time`/`Time(9)` | `Time Nanosecond` |
+| `Null` | `Null` |
+| `Fixed(n)` | `Fixed-Size Binary(n)` |
+| `Interval_year` | `Interval(YearMonth)` |
+| `Interval_day` | `Duration(Microsecond)` |
+| `External(arrow_field_json_str)` | Any Arrow Field |
+
+### External Type Support
+
+For Arrow types not natively mapped in Gravitino, use the
`External(arrow_field_json_str)` type, which accepts a JSON string
representation of an Arrow `Field`.
+
+**Requirements:**
+- JSON must conform to Apache Arrow [Field
specification](https://github.com/apache/arrow-java/blob/ed81e5981a2bee40584b3a411ed755cb4cc5b91f/vector/src/main/java/org/apache/arrow/vector/types/pojo/Field.java#L80C1-L86C68)
+- `name` attribute must match column name exactly
+- `nullable` attribute must match column nullability
+- `children` array:
+ - Empty for primitive types
+ - Contains child field definitions for complex types (Struct, List)
+
+**Examples:**
+
+| Arrow Type | External Type Definition
|
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Large Utf8` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largeutf8\"},\"children\":[]}")`
|
+| `Large Binary` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largebinary\"},\"children\":[]}")`
|
+| `Large List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largelist\"},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+| `Fixed-Size List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"fixedsizelist\",\"listSize\":10},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+
+### Table Properties
+
+Required and optional properties for tables in a Generic Lakehouse Catalog:
+
+| Property | Description
| Default | Required | Since
Version |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|--------------|---------------|
+| `format` | Table format: `lance`, `iceberg`, etc. (currently
only `lance` is fully supported)
| (none) | Yes | 1.1.0
|
+| `location` | Storage path for table metadata and data, Lance
currently supports: S3, GCS, OSS, AZ, File, Memory and file-object-store.
| (none) | Conditional* |
1.1.0 |
+| `external` | Whether the data directory is an external location.
If it's `true`, dropping a table will only remove metadata in Gravitino and
will not delete the data directory, and purge table will delete both. For a
non-external table, dropping will drop both.
| false | No |
1.1.0 |
+| `lance.creation-mode` | Create mode: for create table, it can be `CREATE`,
`EXIST_OK` or `OVERWRITE`. and it should be `CREATE` and `OVERWRITE` for
registering tables
| `CREATE` | No |
1.1.0 |
+| `lance.register` | Whether it is a register table operation. This API
will not create data directory acutally and it's the user responsibility to
create and manage the data directory.
| false | No |
1.1.0 |
+| `lance.storage.xxxx` | Any additional storage-specific properties required
by Lance format (e.g., S3 credentials, HDFS configs). Replace `xxxx` with
actual property names. For example, we can use
`lance.storage.aws_access_key_id` to set S3 aws_access_key_id when using a S3
location, for detail, please refer to
https://lancedb.com/docs/storage/integrations/ | (none) | No |
1.1.0 |
+
+
+**Location Requirement:** Must be specified at catalog, schema, or table
level. See [Location
Resolution](./lakehouse-generic-catalog.md#key-property-location).
+
+You may also set additional properties specific to your lakehouse format or
custom requirements.
+
+### Index Support
+
+Index capabilities vary by lakehouse format. The following table shows Lance
format support:
+
+| Index Type | Description
| Lance Support |
+|------------|----------------------------------------------------------------------------------------------|---------------|
+| SCALAR | Optimizes searches on scalar data types (integers, floats,
etc.) | ✅ |
+| VECTOR | Optimizes similarity searches in high-dimensional vector spaces
| ✅ |
+| BTREE | Balanced tree for sorted data with logarithmic
search/insert/delete complexity | ✅ |
+| INVERTED | Full-text search optimization through term-to-location mapping
| ✅ |
+| IVF_FLAT | Vector search with inverted file and flat quantization
| ✅ |
+| IVF_SQ | Vector search with scalar quantization for memory efficiency
| ✅ |
+| IVF_PQ | Vector search with product quantization balancing accuracy and
memory | ✅ |
+
+:::caution Index Creation Limitation
+**Lance tables do not support index creation during table creation.** You must:
+1. Create the table first
+2. Then create indexes on the created table
+
+This is a fundamental limitation of Lance format, not Gravitino.
+:::
+
+For more details on table indexes, see [Table Partitioning, Distribution, Sort
Ordering, and
Indexes](./manage-relational-metadata-using-gravitino.md#table-partitioning-distribution-sort-ordering-and-indexes).
+
+### Table Operations
+
+Table operations follow standard relational catalog patterns. See [Table
Operations](./manage-relational-metadata-using-gravitino.md#table-operations)
for comprehensive documentation.
+
+The following sections provide examples and important details for working with
Lance tables.
+
+#### Creating a Lance Table
+
+<Tabs groupId='language' queryString>
+<TabItem value="shell" label="Shell">
+
+```shell
+curl -X POST -H "Accept: application/vnd.gravitino.v1+json" \
+ -H "Content-Type: application/json" -d '{
+ "name": "lance_table",
+ "comment": "Example Lance table",
+ "columns": [
+ {
+ "name": "id",
+ "type": "integer",
+ "comment": "Primary identifier",
+ "nullable": false,
+ "autoIncrement": true,
+ "defaultValue": {
+ "type": "literal",
+ "dataType": "integer",
+ "value": "-1"
+ }
+ }
+ ],
+ "properties": {
+ "format": "lance",
+ "location": "/tmp/lance_catalog/schema/lance_table1"
Review Comment:
Inconsistent table naming. The table name is "lance_table" (line 158) but
the location uses "lance_table1" (line 176). These should match for
consistency. Change the location to `/tmp/lance_catalog/schema/lance_table` to
match the table name.
```suggestion
"location": "/tmp/lance_catalog/schema/lance_table"
```
##########
docs/lakehouse-generic-lance-table.md:
##########
@@ -0,0 +1,335 @@
+
+
+---
+title: "Generic lakehouse catalog with Lance"
+slug: /lakehouse-generic-catalog-with-lance
+keywords:
+- lakehouse
+- lance
+- metadata
+- generic catalog
+- file system
+ license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+
+## Overview
+
+This document describes how to use Apache Gravitino to manage a generic
lakehouse catalog using Lance as the underlying table format.
+
+
+## Table Management
+
+### Supported Operations
+
+For Lance tables in a Generic Lakehouse Catalog, the following table
summarizes supported operations:
+
+| Operation | Support Status |
+|-----------|----------------|
+| List | ✅ Full |
+| Load | ✅ Full |
+| Alter | No support now |
+| Create | ✅ Full |
+| Register | ✅ Full |
+| Drop | ✅ Full |
+| Truncate | ✅ Full |
+
+:::note Feature Limitations
+- **Partitioning:** Not currently supported
+- **Sort Orders:** Not currently supported
+- **Distributions:** Not currently supported
+ :::
+
+### Data Type Mappings
+
+Lance uses Apache Arrow for table schemas. The following table shows type
mappings between Gravitino and Arrow:
+
+| Gravitino Type | Arrow Type |
+|----------------------------------|-----------------------------------------|
+| `Struct` | `Struct` |
+| `Map` | `Map` |
+| `List` | `Array` |
+| `Boolean` | `Boolean` |
+| `Byte` | `Int8` |
+| `Short` | `Int16` |
+| `Integer` | `Int32` |
+| `Long` | `Int64` |
+| `Float` | `Float` |
+| `Double` | `Double` |
+| `String` | `Utf8` |
+| `Binary` | `Binary` |
+| `Decimal(p, s)` | `Decimal(p, s)` (128-bit) |
+| `Date` | `Date` |
+| `Timestamp`/`Timestamp(6)` | `TimestampType withoutZone` |
+| `Timestamp(0)` | `TimestampType Second withoutZone` |
+| `Timestamp(3)` | `TimestampType Millisecond withoutZone` |
+| `Timestamp(9)` | `TimestampType Nanosecond withoutZone` |
+| `Timestamp_tz`/`Timestamp_tz(6)` | `TimestampType Microsecond withUtc` |
+| `Timestamp_tz(0)` | `TimestampType Second withUtc` |
+| `Timestamp_tz(3)` | `TimestampType Millisecond withUtc` |
+| `Timestamp_tz(9)` | `TimestampType Nanosecond withUtc` |
+| `Time`/`Time(9)` | `Time Nanosecond` |
+| `Null` | `Null` |
+| `Fixed(n)` | `Fixed-Size Binary(n)` |
+| `Interval_year` | `Interval(YearMonth)` |
+| `Interval_day` | `Duration(Microsecond)` |
+| `External(arrow_field_json_str)` | Any Arrow Field |
+
+### External Type Support
+
+For Arrow types not natively mapped in Gravitino, use the
`External(arrow_field_json_str)` type, which accepts a JSON string
representation of an Arrow `Field`.
+
+**Requirements:**
+- JSON must conform to Apache Arrow [Field
specification](https://github.com/apache/arrow-java/blob/ed81e5981a2bee40584b3a411ed755cb4cc5b91f/vector/src/main/java/org/apache/arrow/vector/types/pojo/Field.java#L80C1-L86C68)
+- `name` attribute must match column name exactly
+- `nullable` attribute must match column nullability
+- `children` array:
+ - Empty for primitive types
+ - Contains child field definitions for complex types (Struct, List)
+
+**Examples:**
+
+| Arrow Type | External Type Definition
|
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Large Utf8` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largeutf8\"},\"children\":[]}")`
|
+| `Large Binary` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largebinary\"},\"children\":[]}")`
|
+| `Large List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largelist\"},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+| `Fixed-Size List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"fixedsizelist\",\"listSize\":10},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+
+### Table Properties
+
+Required and optional properties for tables in a Generic Lakehouse Catalog:
+
+| Property | Description
| Default | Required | Since
Version |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|--------------|---------------|
+| `format` | Table format: `lance`, `iceberg`, etc. (currently
only `lance` is fully supported)
| (none) | Yes | 1.1.0
|
+| `location` | Storage path for table metadata and data, Lance
currently supports: S3, GCS, OSS, AZ, File, Memory and file-object-store.
| (none) | Conditional* |
1.1.0 |
+| `external` | Whether the data directory is an external location.
If it's `true`, dropping a table will only remove metadata in Gravitino and
will not delete the data directory, and purge table will delete both. For a
non-external table, dropping will drop both.
| false | No |
1.1.0 |
+| `lance.creation-mode` | Create mode: for create table, it can be `CREATE`,
`EXIST_OK` or `OVERWRITE`. and it should be `CREATE` and `OVERWRITE` for
registering tables
| `CREATE` | No |
1.1.0 |
+| `lance.register` | Whether it is a register table operation. This API
will not create data directory acutally and it's the user responsibility to
create and manage the data directory.
| false | No |
1.1.0 |
Review Comment:
Grammatical error: "it's the user responsibility" should be "it's the user's
responsibility" (possessive form required).
```suggestion
| `lance.register` | Whether it is a register table operation. This API
will not create data directory acutally and it's the user's responsibility to
create and manage the data directory.
| false | No |
1.1.0 |
```
##########
docs/lance-rest-service.md:
##########
@@ -0,0 +1,390 @@
+---
+title: "Lance REST service"
+slug: /lance-rest-service
+keywords:
+ - Lance REST
+ - Lance datasets
+ - REST API
+license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+## Overview
+
+The Lance REST service provides a RESTful interface for managing Lance
datasets through HTTP endpoints. Introduced in Gravitino version 1.1.0, this
service enables seamless interaction with Lance datasets for data operations
and metadata management.
+
+The service implements the [Lance REST API
specification](https://docs.lancedb.com/api-reference/introduction). For
detailed specification documentation, see the [official Lance REST
documentation](https://lance.org/format/namespace/rest/catalog-spec/).
+
+### What is Lance?
+
+[Lance](https://lance.org/format/) is a modern columnar data format designed
for AI/ML workloads. It provides:
+
+- **High-performance vector search**: Native support for similarity search on
high-dimensional embeddings
+- **Columnar storage**: Optimized for analytical queries and machine learning
pipelines
+- **Fast random access**: Efficient row-level operations unlike traditional
columnar formats
+- **Version control**: Built-in dataset versioning and time-travel capabilities
+- **Incremental updates**: Append and update data without full rewrites
+
+### Architecture
+
+The Lance REST service acts as a bridge between Lance datasets and
applications:
+
+```
+┌─────────────────┐
+│ Applications │
+│ (Python/Java) │
+└────────┬────────┘
+ │ HTTP/REST
+ ▼
+┌─────────────────┐
+│ Lance REST │◄──── Gravitino Metalake
+│ Service │ (Metadata Backend)
+└────────┬────────┘
+ │ File System Operations
+ ▼
+┌─────────────────┐
+│ Lance Datasets │
+│ (S3/GCS/Local) │
+└─────────────────┘
+```
+
+**Key Features:**
+- Full compliance with Lance REST API specification
+- Can run standalone or integrated with Gravitino server
+- Support for namespace and table management
+- Index creation and management capabilities (Index operations are not
supported in version 1.1.0)
+- Metadata stored in Gravitino for unified governance
+
+## Supported Operations
+
+The Lance REST service provides comprehensive support for namespace
management, table management, and index operations. The table below lists all
supported operations:
+
+| Operation | Description
| HTTP Method | Endpoint Pattern | Since Version |
+|-------------------|-------------------------------------------------------------------|-------------|-------------------------------------|---------------|
+| CreateNamespace | Create a new Lance namespace
| POST | `/lance/v1/namespace/{id}/create` | 1.1.0 |
+| ListNamespaces | List all namespaces under a parent namespace
| GET | `/lance/v1/namespace/{parent}/list` | 1.1.0 |
+| DescribeNamespace | Retrieve detailed information about a specific namespace
| POST | `/lance/v1/namespace/{id}/describe` | 1.1.0 |
+| DropNamespace | Delete a namespace
| POST | `/lance/v1/namespace/{id}/drop` | 1.1.0 |
+| NamespaceExists | Check whether a namespace exists
| POST | `/lance/v1/namespace/{id}/exists` | 1.1.0 |
+| ListTables | List all tables in a namespace
| GET | `/lance/v1/table/{namespace}/list` | 1.1.0 |
+| CreateTable | Create a new table in a namespace
| POST | `/lance/v1/table/{id}/create` | 1.1.0 |
+| DropTable | Delete a table including both metadata and data
| POST | `/lance/v1/table/{id}/drop` | 1.1.0 |
+| TableExists | Check whether a table exists
| POST | `/lance/v1/table/{id}/exists` | 1.1.0 |
+| RegisterTable | Register an existing Lance table to a namespace
| POST | `/lance/v1/table/{id}/register` | 1.1.0 |
+| DeregisterTable | Unregister a table from a namespace (metadata only, data
remains) | POST | `/lance/v1/table/{id}/deregister` | 1.1.0 |
+
+More details, please refer to the [Lance REST API
specification](https://lance.org/format/namespace/rest/catalog-spec/)
+
+### Operation Details
+
+Some operations have specific behaviors and modes. Below are important details
to consider:
+
+#### Namespace Operations
+
+**CreateNamespace** supports three modes:
+- `create`: Fails if namespace already exists
+- `exist_ok`: Succeeds even if namespace exists
+- `overwrite`: Replaces existing namespace
+
+**DropNamespace** behavior:
+- Recursively deletes all child namespaces and tables
+- Deletes both metadata and Lance data files
+- Operation is irreversible
+
+#### Table Operations
+
+**RegisterTable vs CreateTable**:
+- **RegisterTable**: Links existing Lance datasets into Gravitino catalog
without data movement
+- **CreateTable**: Creates new Lance table with schema and writes data files
+
+**DropTable vs DeregisterTable**:
+- **DropTable**: Permanently deletes metadata and data files from storage
+- **DeregisterTable**: Removes metadata from Gravitino but preserves Lance
data files
+
+
+## Deployment
+
+### Running with Gravitino Server
+
+To enable the Lance REST service within Gravitino server, configure the
following properties in your Gravitino configuration file:
+
+| Configuration Property | Description
| Default Value |
Required | Since Version |
+|-------------------------------------------|------------------------------------------------------------------------------|-------------------------|----------|---------------|
+| `gravitino.auxService.names` | Auxiliary services to run.
Include `lance-rest` to enable Lance REST service | iceberg-rest,lance-rest |
Yes | 0.2.0 |
+| `gravitino.lance-rest.classpath` | Classpath for Lance REST
service, relative to Gravitino home directory | lance-rest-server/libs |
Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Port number for Lance REST
service | 9101 |
Yes | 1.1.0 |
+| `gravitino.lance-rest.host` | Hostname for Lance REST service
| 0.0.0.0 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
(currently only `gravitino` is supported) | gravitino |
Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino-uri` | Gravitino server URI (required
when namespace-backend is `gravitino`) | http://localhost:8090 | Yes
| 1.1.0 |
+| `gravitino.lance-rest.gravitino-metalake` | Gravitino metalake name
(required when namespace-backend is `gravitino`) | (none)
| Yes | 1.1.0 |
+
+**Example Configuration:**
+
+```properties
+gravitino.auxService.names = lance-rest
+gravitino.lance-rest.httpPort = 9101
+gravitino.lance-rest.host = 0.0.0.0
+gravitino.lance-rest.namespace-backend = gravitino
+gravitino.lance-rest.gravitino.uri = http://localhost:8090
+gravitino.lance-rest.gravitino.metalake-name = my_metalake
+```
+
+### Running Standalone
+
+To run Lance REST service independently without Gravitino server:
+
+```shell
+{GRAVITINO_HOME}/bin/gravitino-lance-rest-server.sh start
+```
+
+Configure the service by editing
`{GRAVITINO_HOME}/conf/gravitino-lance-rest-server.conf` or passing
command-line arguments:
+
+| Configuration Property | Description
| Default Value | Required | Since Version |
+|------------------------------------------------|-----------------------------|-----------------------|----------|---------------|
+| `gravitino.lance-rest.namespace-backend` | Namespace metadata backend
| gravitino | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.uri` | Gravitino server URI
| http://localhost:8090 | Yes | 1.1.0 |
+| `gravitino.lance-rest.gravitino.metalake-name` | Gravitino metalake name
| (none) | Yes | 1.1.0 |
+| `gravitino.lance-rest.httpPort` | Service port number
| 9101 | No | 1.1.0 |
+| `gravitino.lance-rest.host` | Service hostname
| 0.0.0.0 | No | 1.1.0 |
+
+:::tip
+In most cases, you only need to configure
`gravitino.lance-rest.gravitino.metalake-name` and other properties can use
their default values.
+:::
+
+
+### Running with Docker
+
+Launch Lance REST service using Docker:
+
+```shell
+docker run -d --name lance-rest-service -p 9101:9101 \
+ -e LANCE_REST_GRAVITINO_URI=http://gravitino-host:8090 \
+ -e LANCE_REST_GRAVITINO_METALAKE_NAME=your_metalake_name \
+ apache/gravitino-lance-rest:latest
+```
+
+Access the service at `http://localhost:9101`.
+
+**Environment Variables:**
+
+| Environment Variable | Configuration Property
| Required | Default Value | Since Version |
+|--------------------------------------|-------------------------------------------|----------|-------------------------|---------------|
+| `LANCE_REST_NAMESPACE_BACKEND` |
`gravitino.lance-rest.namespace-backend` | No | `gravitino`
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_METALAKE_NAME` |
`gravitino.lance-rest.gravitino-metalake` | Yes | (none)
| 1.1.0 |
+| `LANCE_REST_GRAVITINO_URI` | `gravitino.lance-rest.gravitino-uri`
| No | `http://localhost:8090` | 1.1.0 |
+| `LANCE_REST_HOST` | `gravitino.lance-rest.host`
| No | `0.0.0.0` | 1.1.0 |
+| `LANCE_REST_PORT` | `gravitino.lance-rest.httpPort`
| No | `9101` | 1.1.0 |
+
+:::tip Configuration Tips
+- **Required:** Set `LANCE_REST_GRAVITINO_METALAKE_NAME` to your Gravitino
metalake name
+- **Conditional:** Update `LANCE_REST_GRAVITINO_URI` if Gravitino server is
not on `localhost`
+- **Optional:** Other variables can use default values unless you have
specific requirements
+
+
+## Usage Guidelines
+
+When using Lance REST service with Gravitino backend, keep the following
considerations in mind:
+
+### Prerequisites
+- A running Gravitino server with a created metalake
+
+### Namespace Hierarchy
+Gravitino follows a three-level hierarchy: **catalog → schema → table**. When
creating namespaces or tables:
+
+1. **Parent must exist:** Before creating `lance_catalog/schema`, ensure
`lance_catalog` catalog exists in Gravitino metalake.
+2. **Two-level limit:** You can create namespace `lance_catalog/schema`, but
**not** `lance_catalog/schema/sub_schema`.
+3. **Table placement:** Tables can only be created under
`lance_catalog/schema`, not at catalog level.
+
+**Example Hierarchy:**
+```
+metalake
+└── lance_catalog (catalog - create via REST)
+ └── schema (namespace - create via REST)
+ └── table01 (table - create via REST)
+```
+
+### Delimiter Convention
+
+The Lance REST API uses `$` as the default delimiter to separate namespace
levels in URIs. When making HTTP requests:
+
+- **URL Encoding Required**: `$` must be URL-encoded as `%24`
+- **Example**: `lance_catalog$schema$table01` becomes
`lance_catalog%24schema%24table01` in URLs
+
+**Common Delimiters:**
+```
+Namespace path: lance_catalog.schema.table01
+URI representation: lance_catalog$schema$table01
+URL encoded: lance_catalog%24schema%24table01
+```
+
+:::caution Important Limitations
+- Currently supports only **two levels of namespaces** before tables
+- Tables **cannot** be nested deeper than schema level
+- Parent catalog must be created in Gravitino before using Lance REST API
+- Metadata operations require Gravitino server to be available
+- Namespace deletion is recursive and irreversible
Review Comment:
Missing closing tag for the caution admonition block. The `:::caution
Important Limitations` block (line 222) is not properly closed with `:::`
before the next section starts.
```suggestion
- Namespace deletion is recursive and irreversible
:::
```
##########
docs/lakehouse-generic-lance-table.md:
##########
@@ -0,0 +1,335 @@
+
+
+---
+title: "Generic lakehouse catalog with Lance"
+slug: /lakehouse-generic-catalog-with-lance
+keywords:
+- lakehouse
+- lance
+- metadata
+- generic catalog
+- file system
+ license: "This software is licensed under the Apache License version 2."
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+
+## Overview
+
+This document describes how to use Apache Gravitino to manage a generic
lakehouse catalog using Lance as the underlying table format.
+
+
+## Table Management
+
+### Supported Operations
+
+For Lance tables in a Generic Lakehouse Catalog, the following table
summarizes supported operations:
+
+| Operation | Support Status |
+|-----------|----------------|
+| List | ✅ Full |
+| Load | ✅ Full |
+| Alter | No support now |
+| Create | ✅ Full |
+| Register | ✅ Full |
+| Drop | ✅ Full |
+| Truncate | ✅ Full |
+
+:::note Feature Limitations
+- **Partitioning:** Not currently supported
+- **Sort Orders:** Not currently supported
+- **Distributions:** Not currently supported
+ :::
+
+### Data Type Mappings
+
+Lance uses Apache Arrow for table schemas. The following table shows type
mappings between Gravitino and Arrow:
+
+| Gravitino Type | Arrow Type |
+|----------------------------------|-----------------------------------------|
+| `Struct` | `Struct` |
+| `Map` | `Map` |
+| `List` | `Array` |
+| `Boolean` | `Boolean` |
+| `Byte` | `Int8` |
+| `Short` | `Int16` |
+| `Integer` | `Int32` |
+| `Long` | `Int64` |
+| `Float` | `Float` |
+| `Double` | `Double` |
+| `String` | `Utf8` |
+| `Binary` | `Binary` |
+| `Decimal(p, s)` | `Decimal(p, s)` (128-bit) |
+| `Date` | `Date` |
+| `Timestamp`/`Timestamp(6)` | `TimestampType withoutZone` |
+| `Timestamp(0)` | `TimestampType Second withoutZone` |
+| `Timestamp(3)` | `TimestampType Millisecond withoutZone` |
+| `Timestamp(9)` | `TimestampType Nanosecond withoutZone` |
+| `Timestamp_tz`/`Timestamp_tz(6)` | `TimestampType Microsecond withUtc` |
+| `Timestamp_tz(0)` | `TimestampType Second withUtc` |
+| `Timestamp_tz(3)` | `TimestampType Millisecond withUtc` |
+| `Timestamp_tz(9)` | `TimestampType Nanosecond withUtc` |
+| `Time`/`Time(9)` | `Time Nanosecond` |
+| `Null` | `Null` |
+| `Fixed(n)` | `Fixed-Size Binary(n)` |
+| `Interval_year` | `Interval(YearMonth)` |
+| `Interval_day` | `Duration(Microsecond)` |
+| `External(arrow_field_json_str)` | Any Arrow Field |
+
+### External Type Support
+
+For Arrow types not natively mapped in Gravitino, use the
`External(arrow_field_json_str)` type, which accepts a JSON string
representation of an Arrow `Field`.
+
+**Requirements:**
+- JSON must conform to Apache Arrow [Field
specification](https://github.com/apache/arrow-java/blob/ed81e5981a2bee40584b3a411ed755cb4cc5b91f/vector/src/main/java/org/apache/arrow/vector/types/pojo/Field.java#L80C1-L86C68)
+- `name` attribute must match column name exactly
+- `nullable` attribute must match column nullability
+- `children` array:
+ - Empty for primitive types
+ - Contains child field definitions for complex types (Struct, List)
+
+**Examples:**
+
+| Arrow Type | External Type Definition
|
+|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Large Utf8` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largeutf8\"},\"children\":[]}")`
|
+| `Large Binary` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largebinary\"},\"children\":[]}")`
|
+| `Large List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"largelist\"},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+| `Fixed-Size List` |
`External("{\"name\":\"col_name\",\"nullable\":true,\"type\":{\"name\":\"fixedsizelist\",\"listSize\":10},\"children\":[{\"name\":\"element\",\"nullable\":true,\"type\":{\"name\":\"int\",\"bitWidth\":32,\"isSigned\":true},\"children\":[]}]}")`
|
+
+### Table Properties
+
+Required and optional properties for tables in a Generic Lakehouse Catalog:
+
+| Property | Description
| Default | Required | Since
Version |
+|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|--------------|---------------|
+| `format` | Table format: `lance`, `iceberg`, etc. (currently
only `lance` is fully supported)
| (none) | Yes | 1.1.0
|
+| `location` | Storage path for table metadata and data, Lance
currently supports: S3, GCS, OSS, AZ, File, Memory and file-object-store.
| (none) | Conditional* |
1.1.0 |
+| `external` | Whether the data directory is an external location.
If it's `true`, dropping a table will only remove metadata in Gravitino and
will not delete the data directory, and purge table will delete both. For a
non-external table, dropping will drop both.
| false | No |
1.1.0 |
+| `lance.creation-mode` | Create mode: for create table, it can be `CREATE`,
`EXIST_OK` or `OVERWRITE`. and it should be `CREATE` and `OVERWRITE` for
registering tables
| `CREATE` | No |
1.1.0 |
+| `lance.register` | Whether it is a register table operation. This API
will not create data directory acutally and it's the user responsibility to
create and manage the data directory.
| false | No |
1.1.0 |
+| `lance.storage.xxxx` | Any additional storage-specific properties required
by Lance format (e.g., S3 credentials, HDFS configs). Replace `xxxx` with
actual property names. For example, we can use
`lance.storage.aws_access_key_id` to set S3 aws_access_key_id when using a S3
location, for detail, please refer to
https://lancedb.com/docs/storage/integrations/ | (none) | No |
1.1.0 |
+
+
+**Location Requirement:** Must be specified at catalog, schema, or table
level. See [Location
Resolution](./lakehouse-generic-catalog.md#key-property-location).
+
+You may also set additional properties specific to your lakehouse format or
custom requirements.
+
+### Index Support
+
+Index capabilities vary by lakehouse format. The following table shows Lance
format support:
+
+| Index Type | Description
| Lance Support |
+|------------|----------------------------------------------------------------------------------------------|---------------|
+| SCALAR | Optimizes searches on scalar data types (integers, floats,
etc.) | ✅ |
+| VECTOR | Optimizes similarity searches in high-dimensional vector spaces
| ✅ |
+| BTREE | Balanced tree for sorted data with logarithmic
search/insert/delete complexity | ✅ |
+| INVERTED | Full-text search optimization through term-to-location mapping
| ✅ |
+| IVF_FLAT | Vector search with inverted file and flat quantization
| ✅ |
+| IVF_SQ | Vector search with scalar quantization for memory efficiency
| ✅ |
+| IVF_PQ | Vector search with product quantization balancing accuracy and
memory | ✅ |
+
+:::caution Index Creation Limitation
+**Lance tables do not support index creation during table creation.** You must:
+1. Create the table first
+2. Then create indexes on the created table
+
+This is a fundamental limitation of Lance format, not Gravitino.
+:::
+
+For more details on table indexes, see [Table Partitioning, Distribution, Sort
Ordering, and
Indexes](./manage-relational-metadata-using-gravitino.md#table-partitioning-distribution-sort-ordering-and-indexes).
+
+### Table Operations
+
+Table operations follow standard relational catalog patterns. See [Table
Operations](./manage-relational-metadata-using-gravitino.md#table-operations)
for comprehensive documentation.
+
+The following sections provide examples and important details for working with
Lance tables.
+
+#### Creating a Lance Table
+
+<Tabs groupId='language' queryString>
+<TabItem value="shell" label="Shell">
+
+```shell
+curl -X POST -H "Accept: application/vnd.gravitino.v1+json" \
+ -H "Content-Type: application/json" -d '{
+ "name": "lance_table",
+ "comment": "Example Lance table",
+ "columns": [
+ {
+ "name": "id",
+ "type": "integer",
+ "comment": "Primary identifier",
+ "nullable": false,
+ "autoIncrement": true,
+ "defaultValue": {
+ "type": "literal",
+ "dataType": "integer",
+ "value": "-1"
+ }
Review Comment:
Documentation inconsistency: The example shows using `autoIncrement: true`
and `defaultValue` (lines 166-171), but the catalog support tables indicate
that `lakehouse-generic` does not support default values (line 996) or
auto-increment (line 1014). Either remove these unsupported features from the
example or update the support tables if Lance does support them.
```suggestion
"nullable": false
```
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