Function placed_string_rows 

pub fn placed_string_rows(
    ty: &LogicalType,
    pieces: &[Vector],
    inverse: &[u32],
    range: Range<usize>,
) -> Result<Vector>

The rows in range of the string column interleave_placed would lay through inverse, with an arena of their own.

This is how a sort builds one long string column on several threads. Each range reads every piece and all of inverse and copies only its own strings, so each has a few forward streams to write the way the whole column does, and the ranges share nothing they write.

Errors

If inverse is not as long as the pieces or range runs past it, or if a piece is not flat views, which strings_placeable says beforehand.