2010YOUY01 commented on code in PR #14025: URL: https://github.com/apache/datafusion/pull/14025#discussion_r1904948133
########## datafusion/functions/src/unicode/reverse.rs: ########## @@ -116,14 +115,23 @@ pub fn reverse<T: OffsetSizeTrait>(args: &[ArrayRef]) -> Result<ArrayRef> { } } -fn reverse_impl<'a, T: OffsetSizeTrait, V: ArrayAccessor<Item = &'a str>>( +fn reverse_impl<'a, T: OffsetSizeTrait, V: StringArrayType<'a>>( string_array: V, ) -> Result<ArrayRef> { - let result = ArrayIter::new(string_array) - .map(|string| string.map(|string: &str| string.chars().rev().collect::<String>())) - .collect::<GenericStringArray<T>>(); + let mut builder: GenericStringBuilder<T> = + GenericStringBuilder::with_capacity(string_array.len(), 1024); Review Comment: I think we can use the actual data size here for pre-allocation, instead of a constant 1024, the complexity of adding another argument for array size seems reasonable -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org