Support the tck format for the output of EXPLAIN

docs-2.0/3.ngql-guide/17.query-tuning-statements/1.explain-and-profile.md

@@ -17,18 +17,18 @@ For example, a `SHOW TAGS` statement is processed into two `actions` and assigne
 * `EXPLAIN`
 
     ```ngql
-    EXPLAIN [format= {"row" | "dot"}] <your_nGQL_statement>;
+    EXPLAIN [format= {"row" | "dot" | "tck"}] <your_nGQL_statement>;
     ```
 
 * `PROFILE`
 
     ```ngql
-    PROFILE [format= {"row" | "dot"}] <your_nGQL_statement>;
+    PROFILE [format= {"row" | "dot" | "tck"}] <your_nGQL_statement>;
     ```
 
 ## Output formats
 
-The output of an `EXPLAIN` or a `PROFILE` statement has two formats, the default `row` format and the `dot` format. You can use the `format` option to modify the output format. Omitting the `format` option indicates using the default `row` format.
+The output of an `EXPLAIN` or a `PROFILE` statement has three formats, the default `row` format, the `dot` format, and the `tck` format. You can use the `format` option to modify the output format. Omitting the `format` option indicates using the default `row` format.
 
 ## The `row` format
 
@@ -114,3 +114,39 @@ Execution Plan
 The Graphviz graph transformed from the above DOT statement is as follows.
 
 ![Graphviz graph of EXPLAIN SHOW TAGS](https://docs-cdn.nebula-graph.com.cn/docs-2.0/3.ngql-guide/16.query-tuning-statements/explain-show-tags.png)
+
+## The `tck` format
+
+The tck format is similar to a table, but without borders and dividing lines between rows. You can use the results as test cases for unit testing. 
+For information on tck format test cases, see [TCK cases](https://github.com/vesoft-inc/nebula/tree/master/tests/tck/features).
+
+- `EXPLAIN`
+
+    ```ngql
+    nebula> EXPLAIN format="tck" FETCH PROP ON player "player_1","player_2","player_3" YIELD properties(vertex).name as name, properties(vertex).age as age;
+    Execution succeeded (time spent 261µs/613.718µs)
+    Execution Plan (optimize time 28 us)
+    | id | name        | dependencies | profiling data | operator info |
+    |  2 | Project     | 1            |                |               |
+    |  1 | GetVertices | 0            |                |               |
+    |  0 | Start       |              |                |               |
+
+    Wed, 22 Mar 2023 23:15:52 CST
+    ```
+
+- `PROFILE`
+
+    ```ngql
+    nebula> PROFILE format="tck" FETCH PROP ON player "player_1","player_2","player_3" YIELD properties(vertex).name as name, properties(vertex).age as age;
+    | name         | age |
+    | "Piter Park" | 24  |
+    | "aaa"        | 24  |
+    | "ccc"        | 24  |
+    Got 3 rows (time spent 1.474ms/2.19677ms)
+    Execution Plan (optimize time 41 us)
+    | id | name        | dependencies | profiling data                                                                                                      | operator info |
+    |  2 | Project     | 1            | {"rows":3,"version":0}                                                                                              |               |
+    |  1 | GetVertices | 0            | {"resp[0]":{"exec":"232(us)","host":"127.0.0.1:9779","total":"758(us)"},"rows":3,"total_rpc":"875(us)","version":0} |               |
+    |  0 | Start       |              | {"rows":0,"version":0}                                                                                              |               |
+    Wed, 22 Mar 2023 23:16:13 CST
+    ```