ccxxxyy commented on PR #37561:
URL: https://github.com/apache/shardingsphere/pull/37561#issuecomment-3698081158

   @terrymanu Hi! I hope you can take a look at my latest revision when you 
have time. Thank you for your time.
   
   - Regarding dorisIndexOption: Before I made any modifications, the 
createIndex rule originally included the commonIndexOption rule (KEY_BLOCK_SIZE 
EQ_? NUMBER_  / COMMENT stringLiterals / visibility / ENGINE_ATTRIBUTE EQ_? 
jsonAttribute = string_) Because it conflicts with the commentClause I added, I 
simplified the commonIndexOption to dorisIndexOption and kept it in 
createIndex. However, 
[Doris](https://doris.apache.org/zh-CN/docs/4.x/sql-manual/sql-statements/table-and-view/index/CREATE-INDEX)
 CREATE INDEX actually does not support KEY_BLOCK_SIZE / visibility / 
ENGINE_ATTRIBUTE, as these are specific syntaxes of [MySQL's 
](https://mysql.net.cn/doc/refman/8.0/en/create-index.html) CREATE INDEX. Doris 
is highly compatible with MySQL syntax and supports standard SQL. But there are 
still many [differences 
](https://doris.apache.org/zh-CN/docs/4.x/query-data/mysql-compatibility) 
between Doris and MySQL. Any documentation of Doris mentioning CREATE INDEX 
does not mention KEY_BLOCK_SI
 ZE / visibility / ENGINE_ATTRIBUTE. I couldn't find any description of 
KEY_BLOCK_SIZE / visibility / ENGINE_ATTRIBUTE. Therefore, my approach is to 
remove the added dorisIndexOption to keep consistent with Doris' documentation.
   
   - Although Doris strives to maintain compatibility with MySQL in DDL syntax, 
its index implementation (such as inverted index and Bloom Filter) differs from 
MySQL's B+Tree index. Therefore, there are significant [differences 
](https://doris.apache.org/zh-CN/docs/4.x/query-data/mysql-compatibility#ddl) 
in attribute definitions. Doris's index management is mainly achieved by 
specifying the type using the USING keyword and defining its core parameters in 
conjunction with the PROPERTIES dictionary.


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