Function evaluate_partition_ranges

datafusion/common/src/utils/mod.rs:245–261

Given a list of 0 or more already sorted columns, finds the partition ranges that would partition equally across columns. See [`partition`] for more details.

(
    num_rows: usize,
    partition_columns: &[SortColumn],
)

///
/// See [`partition`] for more details.
pub fn evaluate_partition_ranges(
    num_rows: usize,
    partition_columns: &[SortColumn],
) -> Result<Vec<Range<usize>>> {
    Ok(if partition_columns.is_empty() {
        vec![Range {
            start: 0,
            end: num_rows,
        }]
    } else {
        let cols: Vec<_> = partition_columns
            .iter()
            .map(|x| Arc::clone(&x.values))
            .collect();
        partition(&cols)?.ranges()
    })
}

/// Wraps identifier string in double quotes, escaping any double quotes in
/// the identifier by replacing it with two double quotes