docs: add INFORMATION_SCHEMA REGION_INFO docs (EN + ZH)

docs/reference/sql/information-schema/overview.md

@@ -56,6 +56,7 @@ There is still lots of work to do for `INFORMATION_SCHEMA`. The tracking [issue]
 | Table Name | Description |
 | --- | --- |
 | [`BUILD_INFO`](./build-info.md) | Provides the system build info. |
+| [`REGION_INFO`](./region-info.md) | Provides detailed region runtime and manifest metadata for inspection and debugging. |
 | [`REGION_PEERS`](./region-peers.md) | Provides details about where regions are stored. |
 | [`REGION_STATISTICS`](./region-statistics.md) | Provides details about region statistics info, such as disk size, etc. |
 | [`CLUSTER_INFO`](./cluster-info.md)| Provides the topology information of the cluster.|

docs/reference/sql/information-schema/region-info.md

@@ -0,0 +1,64 @@
+---
+keywords: [region info, region runtime, region manifest, committed sequence, flushed sequence]
+description: Provides detailed region runtime and manifest metadata for inspection and debugging.
+---
+
+# REGION_INFO
+
+The `REGION_INFO` table provides detailed runtime and manifest metadata for regions, useful for inspection and debugging.
+
+```sql
+USE INFORMATION_SCHEMA;
+DESC REGION_INFO;
+```
+
+The output is as follows:
+
+```sql
++------------------------+---------+------+------+---------+---------------+
+| Column                 | Type    | Key  | Null | Default | Semantic Type |
++------------------------+---------+------+------+---------+---------------+
+| region_id              | UInt64  |      | NO   |         | FIELD         |
+| table_id               | UInt32  |      | NO   |         | FIELD         |
+| region_number          | UInt32  |      | NO   |         | FIELD         |
+| region_group           | UInt8   |      | NO   |         | FIELD         |
+| region_sequence        | UInt32  |      | NO   |         | FIELD         |
+| state                  | String  |      | NO   |         | FIELD         |
+| role                   | String  |      | NO   |         | FIELD         |
+| writable               | Boolean |      | NO   |         | FIELD         |
+| committed_sequence     | UInt64  |      | NO   |         | FIELD         |
+| flushed_sequence       | UInt64  |      | YES  |         | FIELD         |
+| manifest_version       | UInt64  |      | NO   |         | FIELD         |
+| compaction_time_window | String  |      | YES  |         | FIELD         |
+| region_options         | String  |      | NO   |         | FIELD         |
+| sst_format             | String  |      | NO   |         | FIELD         |
+| node_id                | UInt64  |      | YES  |         | FIELD         |
++------------------------+---------+------+------+---------+---------------+
+```
+
+Fields in the `REGION_INFO` table are described as follows:
+
+- `region_id`: The ID of the region.
+- `table_id`: The ID of the table.
+- `region_number`: The region number inside the table.
+- `region_group`: The region group.
+- `region_sequence`: The region sequence inside the group.
+- `state`: The detailed runtime role/state label, such as `Leader(Writable)` or `Follower`.
+- `role`: The coarse region role, such as `Leader` or `Follower`.
+- `writable`: Whether the region accepts writes.
+- `committed_sequence`: The committed sequence of the region.
+- `flushed_sequence`: The latest sequence that has been persisted into SST files.
+- `manifest_version`: The manifest version of the region.
+- `compaction_time_window`: The human-readable compaction time window.
+- `region_options`: Region options encoded as JSON.
+- `sst_format`: The SST format used by the region.
+- `node_id`: The datanode ID reporting this row.
+
+Retrieve region info for a specific table as follows:
+
+```sql
+SELECT r.*
+FROM REGION_INFO r
+LEFT JOIN REGION_PEERS p ON r.region_id = p.region_id
+WHERE p.table_name = 'region_info_case';
+```

i18n/zh/docusaurus-plugin-content-docs/current/reference/sql/information-schema/overview.md

@@ -54,6 +54,7 @@ description: INFORMATION_SCHEMA 提供对系统元数据的访问，例如数据
 |表名 | 描述|
 | --- | --- |
 | [`BUILD_INFO`](./build-info.md) | 提供了系统构建的信息。 |
+| [`REGION_INFO`](./region-info.md) | 提供 Region 的运行时和 manifest 详细元数据，用于排查和调试。 |
 | [`REGION_PEERS`](./region-peers.md) | 提供了表的 Region 存储的详细信息。 |
 | [`REGION_STATISTICS`](./region-statistics.md) | 提供 Region 的详细统计信息，例如行数等。 |
 | [`CLUSTER_INFO`](./cluster-info.md)| 提供了集群的节点拓扑信息。|

i18n/zh/docusaurus-plugin-content-docs/current/reference/sql/information-schema/region-info.md

@@ -0,0 +1,64 @@
+---
+keywords: [Region 信息, 运行时元数据, manifest 元数据, committed sequence, flushed sequence]
+description: 提供 Region 的运行时和 manifest 详细元数据，用于排查和调试。
+---
+
+# REGION_INFO
+
+`REGION_INFO` 表提供 Region 的运行时和 manifest 详细元数据，用于排查和调试。
+
+```sql
+USE INFORMATION_SCHEMA;
+DESC REGION_INFO;
+```
+
+输出如下：
+
+```sql
++------------------------+---------+------+------+---------+---------------+
+| Column                 | Type    | Key  | Null | Default | Semantic Type |
++------------------------+---------+------+------+---------+---------------+
+| region_id              | UInt64  |      | NO   |         | FIELD         |
+| table_id               | UInt32  |      | NO   |         | FIELD         |
+| region_number          | UInt32  |      | NO   |         | FIELD         |
+| region_group           | UInt8   |      | NO   |         | FIELD         |
+| region_sequence        | UInt32  |      | NO   |         | FIELD         |
+| state                  | String  |      | NO   |         | FIELD         |
+| role                   | String  |      | NO   |         | FIELD         |
+| writable               | Boolean |      | NO   |         | FIELD         |
+| committed_sequence     | UInt64  |      | NO   |         | FIELD         |
+| flushed_sequence       | UInt64  |      | YES  |         | FIELD         |
+| manifest_version       | UInt64  |      | NO   |         | FIELD         |
+| compaction_time_window | String  |      | YES  |         | FIELD         |
+| region_options         | String  |      | NO   |         | FIELD         |
+| sst_format             | String  |      | NO   |         | FIELD         |
+| node_id                | UInt64  |      | YES  |         | FIELD         |
++------------------------+---------+------+------+---------+---------------+
+```
+
+`REGION_INFO` 表中的字段描述如下：
+
+- `region_id`：Region 的 ID。
+- `table_id`：表的 ID。
+- `region_number`：Region 在表中的编号。
+- `region_group`：Region 组编号。
+- `region_sequence`：Region 在组内的序号。
+- `state`：详细的运行时角色/状态标签，例如 `Leader(Writable)` 或 `Follower`。
+- `role`：Region 的粗粒度角色，例如 `Leader` 或 `Follower`。
+- `writable`：Region 是否可写。
+- `committed_sequence`：Region 的已提交 sequence。
+- `flushed_sequence`：最近已刷入 SST 文件的 sequence。
+- `manifest_version`：Region 的 manifest 版本。
+- `compaction_time_window`：可读格式的 compaction 时间窗口。
+- `region_options`：JSON 编码的 Region 配置项。
+- `sst_format`：Region 使用的 SST 格式。
+- `node_id`：上报该行信息的 datanode ID。
+
+查询某张表的 Region 信息示例如下：
+
+```sql
+SELECT r.*
+FROM REGION_INFO r
+LEFT JOIN REGION_PEERS p ON r.region_id = p.region_id
+WHERE p.table_name = 'region_info_case';
+```