Function sort_batches

datafusion/core/tests/sql/unparser.rs:201–219

Sorts record batches by all columns for deterministic comparison. When comparing query results, we need a canonical ordering so that semantically equivalent results compare as equal. This function sorts by all columns in the schema to achieve that.

(
    ctx: &SessionContext,
    batches: Vec<RecordBatch>,
)

/// semantically equivalent results compare as equal. This function sorts
/// by all columns in the schema to achieve that.
async fn sort_batches(
    ctx: &SessionContext,
    batches: Vec<RecordBatch>,
) -> Result<Vec<RecordBatch>> {
    let mut df = ctx.read_batches(batches)?;
    let schema = df.schema().as_arrow().clone();
    let sort_exprs = schema
        .fields()
        .iter()
        // Use Column directly, col() causes the column names to be normalized to lowercase
        .map(|f| {
            Expr::Column(Column::new_unqualified(f.name().to_string())).sort(true, false)
        })
        .collect_vec();
    if !sort_exprs.is_empty() {
        df = df.sort(sort_exprs)?;
    }
    df.collect().await
}

/// The outcome of running a single roundtrip test.
///