xuyangzhong commented on code in PR #24077:
URL: https://github.com/apache/flink/pull/24077#discussion_r1467302542
##########
docs/content/docs/dev/table/sql/queries/hints.md:
##########
@@ -114,6 +114,42 @@ hintOption:
| stringLiteral
```
+### Conflict Cases In Query Hints
+#### Resolution of Key-value Hint Conflicts
+For key-value hints, which are provided in the following syntax:
+
+```sql
+hintName '(' optionKey '=' optionVal [, optionKey '=' optionVal ]* ')'
+```
+
+When Flink encounters conflicting in key-value hints, it adopts a
last-write-wins strategy. This means that
+if multiple hint values are provided for the same key, Flink will use the
value from the last hint specified
+in the query. For instance, consider the following SQL query with conflicting
'max-attempts' values in the LOOKUP hint:
+
+```sql
+SELECT /*+ LOOKUP('table'='D', 'max-attempts'='3', 'max-attempts'='4') */ *
FROM t1 T JOIN t2 AS OF T.proctime AS D ON T.id = D.id;
+```
+
+In this case, Flink will resolve the conflict by selecting the last specified
value for 'max-attempts'.
+Therefore, the effective hint for 'max-attempts' will be '4'.
+
+#### Resolution of List Hint Conflicts
+List hints are provided using the following syntax:
+
+```sql
+hintName '(' hintOption [, hintOption ]* ')'
+```
+
+With list hints, Flink resolves conflicts by adopting a first-accept strategy.
This means that the
+first specified hint in the list will take precedence and be effective.
+For example, consider the following SQL query with conflicting BROADCAST hints:
+```sql
+SELECT /*+ BROADCAST(t2, t1), BROADCAST(t1, t2) */ * FROM t1;
Review Comment:
ditto.
##########
docs/content.zh/docs/dev/table/sql/queries/hints.md:
##########
@@ -108,6 +108,39 @@ hintOption:
| stringLiteral
```
+### 查询提示使用中的冲突
+#### Key-value 类型查询提示的冲突处理
+Key-value 类型的查询提示使用如下语法：
+
+```sql
+hintName '(' optionKey '=' optionVal [, optionKey '=' optionVal ]* ')'
+```
+
+当 Key-value 类型的查询提示发生冲突时，Flink 会按顺序用后定义的查询提示覆盖前面定义的同名查询提示。
+对于下面的例子，包含同相同 key 的查询提示 'max-attempts'：
+
+```sql
+SELECT /*+ LOOKUP('table'='D', 'max-attempts'='3', 'max-attempts'='4') */ *
FROM t1 T JOIN t2 AS OF T.proctime AS D ON T.id = D.id;
+```
+
+在这个例子里，Flink 会选择 'max-attempts' = '4' 的查询提示覆盖 'max-attempts' = '3' 的提示，
+所以最后 'max-attempts' 的值为 4。
+
+#### List 类型查询提示的冲突处理
+List 类型的查询提示使用如下语法：
+
+```sql
+hintName '(' hintOption [, hintOption ]* ')'
+```
+
+对于 List 类型的查询提示，Flink 会选择最先被采纳的查询提示。如下面具有相同 BROADCAST 提示的例子：
+
+```sql
+SELECT /*+ BROADCAST(t2, t1), BROADCAST(t1, t2) */ * FROM t1;
Review Comment:
The hint is invalid actually.
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