issue_template: add template for performance issue

.github/ISSUE_TEMPLATE/question.md → .github/ISSUE_TEMPLATE/general-question.md

@@ -1,10 +1,10 @@
 ---
-name: "\U0001F914 Question"
+name: "\U0001F914 General Question"
 about: Usage question that isn't answered in docs or discussion
 
 ---
 
-## Question
+## General Question
 
 Before asking a question, make sure you have:
 
@@ -13,4 +13,4 @@ Before asking a question, make sure you have:
 - Searched open and closed [GitHub issues](https://github.com/pingcap/tidb/issues?utf8=%E2%9C%93&q=is%3Aissue)
 - Read the documentation:
   - [TiDB Readme](https://github.com/pingcap/tidb)
-  - [TiDB Doc](https://github.com/pingcap/docs)
+  - [TiDB Doc](https://github.com/pingcap/docs)

.github/ISSUE_TEMPLATE/performance-question.md

@@ -0,0 +1,23 @@
+---
+name: "\U0001F947 Performance Question"
+about: Performance question about TiDB which is not caused by bug.
+
+---
+
+## Performance Question
+
+- What version of TiDB are you using (`tidb-server -V` or run `select tidb_version();` on TiDB)?
+
+- What's the difference between the performance you expect and the performance you observe?
+
+- Are you comparing TiDB with some other database? What's the difference between TiDB and compared one?
+
+- If it's a specific SQL query, could you please
+    - let us know whether you get your result after analyzing the table involved in the query.
+    - tell us whether this SQL always runs slowly, or just occasionally.
+    - provide the `EXPLAIN ANALYZE` result of this query if you can wait until this SQL's execution finishes and your TiDB version is no lower than 2.1, or you can just provide the `EXPLAIN` result.
+    - provide the plain text of the SQL and table schema so we can test it locally. It'll be more better if you can provide the dumped statistics information.
+        - use `show create table ${involved_table}\G` to get the table schema.
+        - use `curl -G "http://${tidb-server-ip}:${tidb-server-status-port}/stats/dump/${db_name}/${table_name}" > ${table_name}_stats.json` to get the dumped statistics of one involved table.
+    - provide the `EXPLAIN` result of the compared database. For mysql, `EXPLAIN format=json`'s result will be more helpful.
+    - other information that you think it's useful to distinguish the property of this SQL.