planner: update SPM doc

sql-plan-management.md

@@ -476,6 +476,54 @@ SHOW binding_cache status;
 1 row in set (0.00 sec)
 ```
 
+## 利用 `Statement Summary` 表获取需要绑定的查询
+
+[`Statement Summary`](/statement-summary-tables.md) 的表中存放了近期的 SQL 相关的执行信息，如延迟、执行次数、对应计划等，通过编写特定的查询访问这些表，可以快速找到需要绑定的查询。
+
+你可以通过查询 `Statement Summary` 表得到符合条件查询的 `plan_digest`，再使用[根据历史执行计划创建绑定](/sql-plan-management.md#根据历史执行计划创建绑定)快速创建绑定。
+
+下面是一个实例，此实例会查找过去 2 周执行次数超过 10 次，执行计划不稳定且未被绑定的 Select 语句，按照执行次数排序，将执行次数前 100 的查询绑定到对应的查询延迟最低的计划上：
+
+```sql
+WITH stmts AS (                                                -- Gets all information
+  SELECT * FROM INFORMATION_SCHEMA.CLUSTER_STATEMENTS_SUMMARY
+  UNION ALL
+  SELECT * FROM INFORMATION_SCHEMA.CLUSTER_STATEMENTS_SUMMARY_HISTORY 
+),
+best_plans AS (
+  SELECT plan_digest, `digest`, avg_latency, 
+  CONCAT('create global binding from history using plan digest "', plan_digest, '"') as binding_stmt 
+  FROM stmts t1
+  WHERE avg_latency = (SELECT min(avg_latency) FROM stmts t2   -- The plan with the loweset query latency
+                       WHERE t2.`digest` = t1.`digest`)
+)
+
+SELECT any_value(digest_text) as query, 
+       SUM(exec_count) as exec_count, 
+       plan_hint, binding_stmt
+FROM stmts, best_plans
+WHERE stmts.`digest` = best_plans.`digest`
+  AND summary_begin_time > DATE_SUB(NOW(), interval 14 day)    -- Executed in the past 2 weeks
+  AND stmt_type = 'Select'                                     -- Only consider select statements
+  AND schema_name NOT IN ('INFORMATION_SCHEMA', 'mysql')       -- Not an internal query
+  AND plan_in_binding = 0                                      -- No binding yet
+GROUP BY stmts.`digest`
+  HAVING COUNT(DISTINCT(stmts.plan_digest)) > 1                -- This query is unstable. It has more than 1 plan.
+         AND SUM(exec_count) > 10                              -- High-frequency, and has been executed more than 10 times.
+ORDER BY SUM(exec_count) DESC LIMIT 100;                       -- Top 100 high-grequency queries.
+```
+
+通过一些过滤条件得到满足条件的查询，然后直接运行 `binding_stmt` 列对应的语句即可创建相应的绑定。
+
+```
++---------------------------------------------+------------+-----------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------+
+| query                                       | exec_count | plan_hint                                                                   | binding_stmt                                                                                                            |
++---------------------------------------------+------------+-----------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------+
+| select * from `t` where `a` = ? and `b` = ? |        401 | use_index(@`sel_1` `test`.`t` `a`), no_order_index(@`sel_1` `test`.`t` `a`) | create global binding from history using plan digest "0d6e97fb1191bbd08dddefa7bd007ec0c422b1416b152662768f43e64a9958a6" |
+| select * from `t` where `b` = ? and `c` = ? |        104 | use_index(@`sel_1` `test`.`t` `b`), no_order_index(@`sel_1` `test`.`t` `b`) | create global binding from history using plan digest "80c2aa0aa7e6d3205755823aa8c6165092c8521fb74c06a9204b8d35fc037dd9" |
++---------------------------------------------+------------+-----------------------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------+
+```
+
 ## 跨数据库绑定执行计划 (Cross-DB Binding)
 
 在创建绑定的 SQL 语句中，TiDB 支持使用通配符 `*` 表示数据库，实现跨数据库绑定。该功能自 v7.6.0 开始引入。要使用跨数据库绑定，首先需要开启 [`tidb_opt_enable_fuzzy_binding`](/system-variables.md#tidb_opt_enable_fuzzy_binding-从-v760-版本开始引入) 系统变量。