update document of tidb-ctl

tidb-control.md

@@ -7,11 +7,19 @@ aliases: ['/docs/dev/tidb-control/','/docs/dev/reference/tools/tidb-control/']
 
 # TiDB Control User Guide
 
-TiDB Control is a command line tool of TiDB, usually used to obtain the status information of TiDB for debugging.
+TiDB Control is a command-line tool of TiDB, usually used to obtain the status information of TiDB for debugging. This document introduces the features of TiDB Control and how to use these features.
 
-## Compile from source code
+## Get TiDB Control
 
-- Compilation environment requirement: [Go](https://golang.org/) Version 1.7 or later
+You can get TiDB Control by installing it using TiUP or by compiling it from source code.
+
+### Install TiDB Control using TiUP
+
+After installing TiUP, you can use `tiup ctl tidb` command to get and execute TiDB Control.
+
+### Compile from source code
+
+- Compilation environment requirement: [Go](https://golang.org/) Version 1.13 or later
 - Compilation procedures: Go to the root directory of the [TiDB Control project](https://github.com/pingcap/tidb-ctl), use the `make` command to compile, and generate `tidb-ctl`.
 - Compilation documentation: you can find the help files in the `doc` directory; if the help files are lost or you want to update them, use the `make doc` command to generate the help files.
 
@@ -32,15 +40,33 @@ Usage example: `tidb-ctl schema in mysql -n db`
 - `-n`: the option
 - `db`: the flag of `-n`
 
+Currently, TiDB Control has the following subcommands:
+
+- `tidb-ctl base64decode`: used for `BASE64` decoding
+- `tidb-ctl decoder`: used for `KEY` decoding
+- `tidb-ctl etcd`: used for operating etcd
+- `tidb-ctl log`: used to format the log file to expand the single-line stack information
+- `tidb-ctl mvcc`: used to get the MVCC information
+- `tidb-ctl region`: used to get the Region information
+- `tidb-ctl schema`: used to get the schema information
+- `tidb-ctl table`: used to get the table information
+
 ### Get help
 
 Use `tidb-ctl -h/--help` to get usage information.
 
 TiDB Control consists of multiple layers of commands. You can use `-h/--help` after each command/subcommand to get its respective usage information.
 
-### Connect
+The following example shows how to obtain the schema information:
+
+Use `tidb-ctl schema -h` to get usage details. The `schema` command itself has two subcommands: `in` and `tid`.
 
-`tidb-ctl` has 4 connection related options:
+- `in` is used to obtain the table schema of all tables in the database through the database name.
+- `tid` is used to obtain the table schema by using the unique `table_id` in the whole database.
+
+### Global options
+
+`tidb-ctl` has the following connection-related global options:
 
 - `--host`: TiDB Service address (default 127.0.0.1)
 - `--port`: TiDB Service port (default 10080)
@@ -56,33 +82,11 @@ TiDB Control consists of multiple layers of commands. You can use `-h/--help` af
 - The default service port of TiDB: `10080`.
 - The default service port of PD: `2379`.
 
-**Connection options are global options that apply to all the following commands:**
-
-- `tidb-ctl base64decode`: BASE64 decode
-- `tidb-ctl decoder`: for KEY decode
-- `tidb-ctl etcd`: for operating etcd
-- `tidb-ctl log`: format the log file to expand the single-line stack information
-- `tidb-ctl mvcc`: MVCC information
-- `tidb-ctl region`: Region information
-- `tidb-ctl schema`: Schema information
-- `tidb-ctl table`: Table information
+### The `schema` command
 
-For details about how to use the above `tidb-ctl` commands, use `tidb-ctl SUBCOMMAND --help` to get the help information.
+#### The `in` subcommand
 
-### Usage examples
-
-The following example shows how to obtain the schema information:
-
-Use `tidb-ctl schema -h` to get usage details. The `schema` command itself has two subcommands: `in` and `tid`.
-
-- `in` is used to obtain the table schema of all tables in the database through the database name.
-- `tid` is used to obtain the table schema by using the unique `table_id` in the whole database.
-
-#### The `in` command
-
-You can use `tidb-ctl schema in -h/--help` to get the help information of the `in` subcommand.
-
-##### Basic usage
+`in` is used to obtain the table schema of all tables in the database through the database name.
 
 ```bash
 tidb-ctl schema in <database name>
@@ -128,7 +132,28 @@ The result is displayed in the JSON format. (The above output is truncated.)
 
     If you do not want to use the default TiDB service address and port, use the `--host` and `--port` options to configure. For example, `tidb-ctl --host 172.16.55.88 --port 8898 schema in mysql -n db`.
 
-#### The `base64decode` subcommand
+#### The `tid` subcommand
+
+`tid` is used to obtain the table schema by using the unique `table_id` in the whole database. You can use the `in` subcommand to get all table IDs of certain schema and use the `tid` subcommand to get the detailed table information.
+
+For example, the table ID of `mysql.stat_meta` is `21`. You can use `tidb-ctl schema tid -i 21` to obtain the detail of `mysql.stat_meta`.
+
+```json
+{
+ "id": 21,
+ "name": {
+  "O": "stats_meta",
+  "L": "stats_meta"
+ },
+ "charset": "utf8mb4",
+ "collate": "utf8mb4_bin",
+  ...
+}
+``` 
+
+Like the `in` subcommand, if you do not want to use the default TiDB service address and port, use the `--host` and `--port` options to specify the host and port.
+
+#### The `base64decode` command
 
 `base64decode` is used to decode `base64` data.
 
@@ -204,25 +229,27 @@ tidb-ctl base64decode [table_id] [base64_data]
     e not found in data
     ```
 
-#### The `decoder` subcommand
+### The `decoder` command
 
 - The following example shows how to decode the row key, similar to decoding the index key.
 
     ```shell
-    $ ./tidb-ctl decoder -f table_row -k "t\x00\x00\x00\x00\x00\x00\x00\x1c_r\x00\x00\x00\x00\x00\x00\x00\xfa"
-    table_id: -9223372036854775780
-    row_id: -9223372036854775558
+    $ ./tidb-ctl decoder "t\x00\x00\x00\x00\x00\x00\x00\x1c_r\x00\x00\x00\x00\x00\x00\x00\xfa"
+    format: table_row
+    table_id: -9223372036854775780      table_id: -9223372036854775780
+    row_id: -9223372036854775558        row_id: -9223372036854775558
     ```
 
 - The following example shows how to decode `value`.
 
     ```shell
-    $ ./tidb-ctl decoder -f value -k AhZoZWxsbyB3b3JsZAiAEA==
-    type: bytes, value: hello world
-    type: bigint, value: 1024
+    $ ./tidb-ctl decoder AhZoZWxsbyB3b3JsZAiAEA==
+    format: index_value
+    type: bigint, value: 1024       index_value[0]: {type: bytes, value: hello world}
+    index_value[1]: {type: bigint, value: 1024}
     ```
 
-#### The `etcd` subcommand
+### The `etcd` command
 
 - `tidb-ctl etcd ddlinfo` is used to obtain DDL information.
 - `tidb-ctl etcd putkey KEY VALUE` is used to add KEY VALUE to etcd (All the KEYs are added to the `/tidb/ddl/all_schema_versions/` directory).
@@ -240,11 +267,11 @@ tidb-ctl base64decode [table_id] [base64_data]
     tidb-ctl etcd delkey "/tidb/ddl/all_schema_versions/bar"
     ```
 
-#### The `log` subcommand
+### The `log` command
 
 The stack information for the TiDB error log is in one line format. You could use `tidb-ctl log` to change its format to multiple lines.
 
-#### The `keyrange` subcommand
+### The `keyrange` command
 
 The `keyrange` subcommand is used to query the global or table-related key range information, which is output in the hexadecimal form.