is_cheap_and_infallible

datafusion_physical_expr::expressions::case

Function is_cheap_and_infallible 

Source 
fn is_cheap_and_infallible(expr: &Arc<dyn PhysicalExpr>) -> bool
Expand description

This is a specialization for a specific use case where we can take a fast path for expressions that are infallible and can be cheaply computed for the entire record batch rather than just for the rows where the predicate is true. For now, this is limited to use with Column expressions but could potentially be used for other expressions in the future