tikv: fixed some description about --db and compact-cluster (#14576)

tikv-control.md

@@ -300,7 +300,8 @@ Use the `compact` command to manually compact data of each TiKV.
 
 - Use the `--from` and `--to` options to specify the compaction range in the form of escaped raw key. If not set, the whole range will be compacted.
 - Use the `--region` option to compact the range of a specific region. If set, `--from` and `--to` will be ignored.
-- Use the `--db` option to specify the RocksDB that performs compaction. The optional values are `kv` and `raft`.
+- Use the `-c` option to specify the column family name. The default value is `default`. The optional values are `default`, `lock`, and `write`.
+- Use the `-d` option to specify the RocksDB that performs compaction. The default value is `kv`. The optional values are `kv` and `raft`.
 - Use the `--threads` option allows you to specify the concurrency for the TiKV compaction and its default value is `8`. Generally, a higher concurrency comes with a faster compaction speed, which might yet affect the service. You need to choose an appropriate concurrency count based on your scenario.
 - Use the `--bottommost` option to include or exclude the bottommost files when TiKV performs compaction. The value options are `default`, `skip`, and `force`. The default value is `default`.
     - `default` means that the bottommost files are included only when the Compaction Filter feature is enabled.
@@ -310,18 +311,21 @@ Use the `compact` command to manually compact data of each TiKV.
 - To compact data in the local mode, use the following command:
 
     ```shell
-    tikv-ctl --data-dir /path/to/tikv compact --db kv
+    tikv-ctl --data-dir /path/to/tikv compact -d kv
     ```
 
 - To compact data in the remote mode, use the following command:
 
     ```shell
-    tikv-ctl --host ip:port compact --db kv
+    tikv-ctl --host ip:port compact -d kv
     ```
 
 ### Compact data of the whole TiKV cluster manually
 
-Use the `compact-cluster` command to manually compact data of the whole TiKV cluster. The flags of this command have the same meanings and usage as those of the `compact` command.
+Use the `compact-cluster` command to manually compact data of the whole TiKV cluster. The flags of this command have the same meanings and usage as those of the `compact` command. The only difference is as follows:
+
+- For the `compact-cluster` command, use `--pd` to specify the address of the PD, so that `tikv-ctl` can locate all TiKV nodes in the cluster as the compact target.
+- For the `compact` command, use `--data-dir` or `--host` to specify a single TiKV as the compact target.
 
 ### Set a Region to tombstone