cloud: document Premium import workflows (#21968)

Author: alastori

TOC-tidb-cloud-premium.md

@@ -205,15 +205,16 @@
 - Migrate or Import Data
   - [Overview](/tidb-cloud/tidb-cloud-migration-overview.md)
   - Migrate Data into TiDB Cloud
-    - [Migrate from TiDB Self-Managed to TiDB Cloud](/tidb-cloud/migrate-from-op-tidb.md)
+    - [Migrate from TiDB Self-Managed to TiDB Cloud Premium](/tidb-cloud/premium/migrate-from-op-tidb-premium.md)
     - [Migrate and Merge MySQL Shards of Large Datasets](/tidb-cloud/migrate-sql-shards.md)
     - [Migrate from Amazon RDS for Oracle Using AWS DMS](/tidb-cloud/migrate-from-oracle-using-aws-dms.md)
   - Import Data into TiDB Cloud
     - [Import Sample Data (SQL Files) from Cloud Storage](/tidb-cloud/import-sample-data-serverless.md)
-    - [Import CSV Files from Cloud Storage](/tidb-cloud/import-csv-files-serverless.md)
+    - [Import CSV Files from Cloud Storage](/tidb-cloud/premium/import-csv-files-premium.md)
+    - [Import CSV Files from Amazon S3](/tidb-cloud/premium/import-from-s3-premium.md)
     - [Import Parquet Files from Cloud Storage](/tidb-cloud/import-parquet-files-serverless.md)
     - [Import Snapshot Files from Cloud Storage](/tidb-cloud/import-snapshot-files-serverless.md)
-    - [Import with MySQL CLI](/tidb-cloud/import-with-mysql-cli-serverless.md)
+    - [Import Data Using MySQL CLI](/tidb-cloud/premium/import-with-mysql-cli-premium.md)
   - Reference
     - [Configure External Storage Access for TiDB Cloud](/tidb-cloud/serverless-external-storage.md)
     - [Naming Conventions for Data Import](/tidb-cloud/naming-conventions-for-data-import.md)

tidb-cloud/import-csv-files-serverless.md

@@ -13,13 +13,13 @@ This document describes how to import CSV files from Amazon Simple Storage Servi
 
 ## Limitations
 
-- To ensure data consistency, TiDB Cloud allows to import CSV files into empty tables only. To import data into an existing table that already contains data, you can import the data into a temporary empty table by following this document, and then use the `INSERT SELECT` statement to copy the data to the target existing table.
+- To ensure data consistency, TiDB Cloud allows importing CSV files into empty tables only. To import data into an existing table that already contains data, you can import the data into a temporary empty table by following this document, and then use the `INSERT SELECT` statement to copy the data to the target existing table.
 
 ## Step 1. Prepare the CSV files
 
-1. If a CSV file is larger than 256 MB, consider splitting it into smaller files, each with a size around 256 MB.
+1. If a CSV file is larger than 256 MiB, consider splitting it into smaller files, each with a size around 256 MiB.
 
-    TiDB Cloud supports importing very large CSV files but performs best with multiple input files around 256 MB in size. This is because TiDB Cloud can process multiple files in parallel, which can greatly improve the import speed.
+    TiDB Cloud supports importing very large CSV files but performs best with multiple input files around 256 MiB in size. This is because TiDB Cloud can process multiple files in parallel, which can greatly improve the import speed.
 
 2. Name the CSV files as follows:
 

tidb-cloud/import-csv-files.md

@@ -10,15 +10,15 @@ This document describes how to import CSV files from Amazon Simple Storage Servi
 
 ## Limitations
 
-- To ensure data consistency, TiDB Cloud allows to import CSV files into empty tables only. To import data into an existing table that already contains data, you can use TiDB Cloud to import the data into a temporary empty table by following this document, and then use the `INSERT SELECT` statement to copy the data to the target existing table.
+- To ensure data consistency, TiDB Cloud allows importing CSV files into empty tables only. To import data into an existing table that already contains data, you can use TiDB Cloud to import the data into a temporary empty table by following this document, and then use the `INSERT SELECT` statement to copy the data to the target existing table.
 
 - If a TiDB Cloud Dedicated cluster has a [changefeed](/tidb-cloud/changefeed-overview.md) or has [Point-in-time Restore](/tidb-cloud/backup-and-restore.md#turn-on-point-in-time-restore) enabled, you cannot import data to the cluster (the **Import Data** button will be disabled) because the current data import feature uses the [physical import mode](https://docs.pingcap.com/tidb/stable/tidb-lightning-physical-import-mode). In this mode, the imported data does not generate change logs, so the changefeed and Point-in-time Restore cannot detect the imported data.
 
 ## Step 1. Prepare the CSV files
 
-1. If a CSV file is larger than 256 MB, consider splitting it into smaller files, each with a size of around 256 MB.
+1. If a CSV file is larger than 256 MiB, consider splitting it into smaller files, each with a size of around 256 MiB.
 
-    TiDB Cloud supports importing very large CSV files but performs best with multiple input files around 256 MB in size. This is because TiDB Cloud can process multiple files in parallel, which can greatly improve the import speed.
+    TiDB Cloud supports importing very large CSV files but performs best with multiple input files around 256 MiB in size. This is because TiDB Cloud can process multiple files in parallel, which can greatly improve the import speed.
 
 2. Name the CSV files as follows:
 

tidb-cloud/import-with-mysql-cli-serverless.md

@@ -53,7 +53,7 @@ INSERT INTO products (product_id, product_name, price) VALUES
     (3, 'Tablet', 299.99);
 ```
 
-## Step 3. Import data from a SQL or CSV file
+## Step 3. Import data from an SQL or CSV file
 
 You can import data from an SQL file or a CSV file. The following sections provide step-by-step instructions for importing data from each type.
 

tidb-cloud/import-with-mysql-cli.md

@@ -49,7 +49,7 @@ INSERT INTO products (product_id, product_name, price) VALUES
     (3, 'Tablet', 299.99);
 ```
 
-## Step 3. Import data from a SQL or CSV file
+## Step 3. Import data from an SQL or CSV file
 
 You can import data from an SQL file or a CSV file. The following sections provide step-by-step instructions for importing data from each type.
 

tidb-cloud/migrate-from-op-tidb.md

@@ -5,15 +5,15 @@ summary: Learn how to migrate data from TiDB Self-Managed to TiDB Cloud.
 
 # Migrate from TiDB Self-Managed to TiDB Cloud
 
-This document describes how to migrate data from your TiDB Self-Managed clusters to TiDB Cloud (AWS) through Dumpling and TiCDC.
+This document describes how to migrate data from your TiDB Self-Managed clusters to TiDB Cloud (on AWS) through Dumpling and TiCDC.
 
 The overall procedure is as follows:
 
 1. Build the environment and prepare the tools.
 2. Migrate full data. The process is as follows:
    1. Export data from TiDB Self-Managed to Amazon S3 using Dumpling.
    2. Import data from Amazon S3 to TiDB Cloud.
-3. Replicate incremental data by using TiCDC.
+3. Replicate incremental data using TiCDC.
 4. Verify the migrated data.
 
 ## Prerequisites