Function plan_window_function_common

src/sql/src/plan/query.rs:5884–5931

The common part of the planning of all window functions.

(
    ecx: &ExprContext,
    name: &<Aug as AstInfo>::ItemName,
    over: &Option<WindowSpec<Aug>>,
)

/// The common part of the planning of all window functions.
fn plan_window_function_common(
    ecx: &ExprContext,
    name: &<Aug as AstInfo>::ItemName,
    over: &Option<WindowSpec<Aug>>,
) -> Result<
    (
        bool,
        Vec<HirScalarExpr>,
        Vec<ColumnOrder>,
        mz_expr::WindowFrame,
        Vec<HirScalarExpr>,
    ),
    PlanError,
> {
    if !ecx.allow_windows {
        sql_bail!(
            "window functions are not allowed in {} (function {})",
            ecx.name,
            name
        );
    }

    let window_spec = match over.as_ref() {
        Some(over) => over,
        None => sql_bail!("window function {} requires an OVER clause", name),
    };
    if window_spec.ignore_nulls && window_spec.respect_nulls {
        sql_bail!("Both IGNORE NULLS and RESPECT NULLS were given.");
    }
    let window_frame = match window_spec.window_frame.as_ref() {
        Some(frame) => plan_window_frame(frame)?,
        None => mz_expr::WindowFrame::default(),
    };
    let mut partition = Vec::new();
    for expr in &window_spec.partition_by {
        partition.push(plan_expr(ecx, expr)?.type_as_any(ecx)?);
    }

    let (order_by_exprs, col_orders) = plan_function_order_by(ecx, &window_spec.order_by)?;

    Ok((
        window_spec.ignore_nulls,
        order_by_exprs,
        col_orders,
        window_frame,
        partition,
    ))
}

fn plan_window_frame(
    WindowFrame {