KevinyhZou opened a new issue, #6057: URL: https://github.com/apache/incubator-gluten/issues/6057
### Description Now that the char/varchar type of hive table are always convert to string type in clickhouse backend. And the char type in hive table means the field has fixed bytes, which is suitable to converted to `FixedString` type in clickhouse. And in some suitation, the fixed string type can have better performance that the string type in clickhouse. such as where the querys contains order by. Here we defined 2 tables, has the same data, the first one is defined as `test_tbl1(id UInt64, d String)`, and the second is defined as `test_tbl2(id UInt64, d FixedString(20))`, and we do the query `select * from test_tbl order by d limit 100 settings max_threads=1` to compare the performance In the first table, the result show as below  In the second table, the result show as below  and we can see that abort 20% performance improve when the table field is defined as `FixedString` type. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
