datafusion 17.0.0

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//! Collection of utility functions that are leveraged by the query optimizer rules

use super::optimizer::PhysicalOptimizerRule;

use crate::config::ConfigOptions;
use crate::error::Result;
use crate::physical_plan::sorts::sort::SortExec;
use crate::physical_plan::{with_new_children_if_necessary, ExecutionPlan};
use datafusion_physical_expr::PhysicalSortExpr;
use std::sync::Arc;

/// Convenience rule for writing optimizers: recursively invoke
/// optimize on plan's children and then return a node of the same
/// type. Useful for optimizer rules which want to leave the type
/// of plan unchanged but still apply to the children.
pub fn optimize_children(
    optimizer: &impl PhysicalOptimizerRule,
    plan: Arc<dyn ExecutionPlan>,
    config: &ConfigOptions,
) -> Result<Arc<dyn ExecutionPlan>> {
    let children = plan
        .children()
        .iter()
        .map(|child| optimizer.optimize(Arc::clone(child), config))
        .collect::<Result<Vec<_>>>()?;

    if children.is_empty() {
        Ok(Arc::clone(&plan))
    } else {
        with_new_children_if_necessary(plan, children)
    }
}

/// Util function to add SortExec above child
/// preserving the original partitioning
pub fn add_sort_above_child(
    child: &Arc<dyn ExecutionPlan>,
    sort_expr: Vec<PhysicalSortExpr>,
) -> Result<Arc<dyn ExecutionPlan>> {
    let new_child = if child.output_partitioning().partition_count() > 1 {
        Arc::new(SortExec::new_with_partitioning(
            sort_expr,
            child.clone(),
            true,
            None,
        )) as Arc<dyn ExecutionPlan>
    } else {
        Arc::new(SortExec::try_new(sort_expr, child.clone(), None)?)
            as Arc<dyn ExecutionPlan>
    };
    Ok(new_child)
}