premium: add limitations on import and index creation

sql-statements/sql-statement-admin-alter-ddl.md

@@ -31,6 +31,14 @@ The following are the supported parameters for different DDL jobs and their corr
 
   Currently, the preceding parameters only work for `ADD INDEX` jobs that are submitted and running after [`tidb_enable_dist_task`](/system-variables.md#tidb_enable_dist_task-new-in-v710) is disabled.
 
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, both `THREAD` and `MAX_WRITE_SPEED` are automatically tuned to appropriate values and cannot be modified by users. If you need to adjust these settings, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+</CustomContent>
+
 - `MODIFY COLUMN`:
     - `THREAD`: the concurrency of the DDL job. The initial value is set by `tidb_ddl_reorg_worker_cnt`.
     - `BATCH_SIZE`: the batch size. The initial value is set by `tidb_ddl_reorg_batch_size`.

sql-statements/sql-statement-import-into.md

@@ -159,6 +159,14 @@ The supported options are described as follows:
 | `CLOUD_STORAGE_URI` | All file formats | Specifies the target address where encoded KV data for [Global Sort](/tidb-global-sort.md) is stored. When `CLOUD_STORAGE_URI` is not specified, `IMPORT INTO` determines whether to use Global Sort based on the value of the system variable [`tidb_cloud_storage_uri`](/system-variables.md#tidb_cloud_storage_uri-new-in-v740). If this system variable specifies a target storage address, `IMPORT INTO` uses this address for Global Sort. When `CLOUD_STORAGE_URI` is specified with a non-empty value, `IMPORT INTO` uses that value as the target storage address. When `CLOUD_STORAGE_URI` is specified with an empty value, local sorting is enforced. Currently, the target storage address only supports S3. For details about the URI configuration, see [Amazon S3 URI format](/external-storage-uri.md#amazon-s3-uri-format). When this feature is used, all TiDB nodes must have read and write access for the target S3 bucket, including at least these permissions: `s3:ListBucket`, `s3:GetObject`, `s3:DeleteObject`, `s3:PutObject`, `s3: AbortMultipartUpload`. |
 | `DISABLE_PRECHECK` | All file formats and query results of `SELECT` | Setting this option disables pre-checks of non-critical items, such as checking whether there are CDC or PITR tasks.  |
 
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, the following four options — `DISK_QUOTA`, `THREAD`, `MAX_WRITE_SPEED`, and `CLOUD_STORAGE_URI` — are automatically tuned to appropriate values and cannot be modified by users. If you need to adjust these settings, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+</CustomContent>
+
 ## `IMPORT INTO ... FROM FILE` usage
 
 For TiDB Self-Managed, `IMPORT INTO ... FROM FILE` supports importing data from files stored in Amazon S3, GCS, and the TiDB local storage. For [TiDB Cloud Dedicated](https://docs.pingcap.com/tidbcloud/select-cluster-tier#tidb-cloud-dedicated), `IMPORT INTO ... FROM FILE` supports importing data from files stored in Amazon S3 and GCS. For [{{{ .starter }}}](https://docs.pingcap.com/tidbcloud/select-cluster-tier#starter) and [{{{ .essential }}}](https://docs.pingcap.com/tidbcloud/select-cluster-tier#essential), `IMPORT INTO ... FROM FILE` supports importing data from files stored in Amazon S3 and Alibaba Cloud OSS.

system-variables.md

@@ -1576,10 +1576,22 @@ mysql> SELECT job_info FROM mysql.analyze_jobs ORDER BY end_time DESC LIMIT 1;
 
 ### tidb_ddl_disk_quota <span class="version-mark">New in v6.3.0</span>
 
+<CustomContent platform="tidb-cloud" plan="starter,essential">
+
 > **Note:**
 >
 > This variable is read-only for [{{{ .starter }}}](https://docs.pingcap.com/tidbcloud/select-cluster-tier#starter) and [{{{ .essential }}}](https://docs.pingcap.com/tidbcloud/select-cluster-tier#essential).
 
+</CustomContent>
+
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> This variable is read-only for [{{{ .premium }}}](https://docs-preview.pingcap.com/tidbcloud/tidb-cloud-intro/#deployment-options).
+
+</CustomContent>
+
 - Scope: GLOBAL
 - Persists to cluster: Yes
 - Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No
@@ -1606,6 +1618,14 @@ mysql> SELECT job_info FROM mysql.analyze_jobs ORDER BY end_time DESC LIMIT 1;
 - Starting from v7.1.0, the index acceleration operation supports checkpoints. Even if the TiDB owner node is restarted or changed due to failures, TiDB can still recover progress from checkpoints that are automatically updated on a regular basis.
 - To verify whether a completed `ADD INDEX` operation is accelerated, you can execute the [`ADMIN SHOW DDL JOBS`](/sql-statements/sql-statement-admin-show-ddl.md#admin-show-ddl-jobs) statement to see whether `ingest` is displayed in the `JOB_TYPE` column.
 
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, the variable is read-only. If you need to modify it, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+</CustomContent>
+
 <CustomContent platform="tidb">
 
 > **Note:**
@@ -1636,6 +1656,14 @@ mysql> SELECT job_info FROM mysql.analyze_jobs ORDER BY end_time DESC LIMIT 1;
 - Starting from TiDB v8.1.0, this variable is enabled by default. If you want to upgrade a cluster with the DXF enabled to v8.1.0 or later, disable the DXF (by setting `tidb_enable_dist_task` to `OFF`) before the upgrade, which avoids `ADD INDEX` operations during the upgrade causing data index inconsistency. After the upgrade, you can manually enable the DXF.
 - This variable is renamed from `tidb_ddl_distribute_reorg`.
 
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, the variable is read-only. If you need to modify it, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+</CustomContent>
+
 ### tidb_cloud_storage_uri <span class="version-mark">New in v7.4.0</span>
 
 > **Note:**
@@ -1733,12 +1761,36 @@ Assume that you have a cluster with 4 TiDB nodes and multiple TiKV nodes. In thi
 - When Global Sort is disabled, only one TiDB node writes to TiKV at a time. In this case, the maximum write bandwidth per TiKV node is `100MiB`.
 - When Global Sort is enabled, all 4 TiDB nodes can write to TiKV simultaneously. In this case, the maximum write bandwidth per TiKV node is `4 * 100MiB = 400MiB`.
 
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, this variable is automatically tuned to an appropriate value and cannot be modified by users. If you need to adjust the setting, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+</CustomContent>
+
 ### tidb_ddl_reorg_worker_cnt
 
+<CustomContent platform="tidb-cloud">
+
+<CustomContent plan="starter,essential">
+
 > **Note:**
 >
 > This variable is read-only for [{{{ .starter }}}](https://docs.pingcap.com/tidbcloud/select-cluster-tier#starter) and [{{{ .essential }}}](https://docs.pingcap.com/tidbcloud/select-cluster-tier#essential).
 
+</CustomContent>
+
+<CustomContent plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, modifying this TiDB variable takes effect only on `MODIFY COLUMN` DDL jobs and does not affect `ADD INDEX` DDL jobs.
+
+</CustomContent>
+
+</CustomContent>
+
 - Scope: SESSION | GLOBAL
 - Persists to cluster: Yes
 - Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No
@@ -2335,6 +2387,14 @@ Assume that you have a cluster with 4 TiDB nodes and multiple TiKV nodes. In thi
 - Default value: `ON`
 - This variable is used to set whether to enable the [Metadata lock](/metadata-lock.md) feature. Note that when setting this variable, you need to make sure that there are no running DDL statements in the cluster. Otherwise, the data might be incorrect or inconsistent.
 
+<CustomContent platform="tidb-cloud" plan="premium">
+
+> **Note:**
+>
+> For {{{ .premium }}}, the variable is read-only. If you need to modify it, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+</CustomContent>
+
 ### tidb_enable_mutation_checker <span class="version-mark">New in v6.0.0</span>
 
 - Scope: SESSION | GLOBAL

tidb-global-sort.md

@@ -60,6 +60,14 @@ To enable Global Sort, follow these steps:
     SET GLOBAL tidb_cloud_storage_uri = 's3://my-bucket/test-data?role-arn=arn:aws:iam::888888888888:role/my-role'
     ```
 
+    <CustomContent plan="premium">
+
+    > **Note:**
+    >
+    > For {{{ .premium }}}, this parameter is automatically configured and does not require manual adjustment. If you need to modify it, contact [TiDB Cloud Support](/tidb-cloud/tidb-cloud-support.md).
+
+    </CustomContent>
+
 </CustomContent>
 
 > **Note:**