*: improve INL_HASH_JOIN document about collation incompatibility

optimizer-hints.md

@@ -930,9 +930,9 @@ The warning is as follows:
 
 In this case, you need to place the hint directly after the `SELECT` keyword. For more details, see the [Syntax](#syntax) section.
 
-### INL_JOIN hint does not take effect due to collation incompatibility
+### INL_JOIN, INL_HASH_JOIN, INL_MERGE_JOIN hint does not take effect due to collation incompatibility
 
-When the collation of the join key is incompatible between two tables, the `IndexJoin` operator cannot be utilized to execute the query. In this case, the [`INL_JOIN` hint](#inl_joint1_name--tl_name-) does not take effect. For example:
+When the collation of the join key is incompatible between two tables, the `IndexJoin` operator cannot be utilized to execute the query. In this case, the [`INL_JOIN` hint](#inl_joint1_name--tl_name-), [`INL_HASH_JOIN` hint](#inl_hash_join) or [`INL_MERGE_JOIN`](#inl_merge_join) does not take effect. For example:
 
 ```sql
 CREATE TABLE t1 (k varchar(8), key(k)) COLLATE=utf8mb4_general_ci;