datafusion_python::optimizer::optimize_projections

Function is_projection_unnecessary

Source 
pub fn is_projection_unnecessary(
    input: &LogicalPlan,
    proj_exprs: &[Expr],
) -> Result<bool, DataFusionError>
Expand description

Projection is unnecessary, when

  • input schema of the projection, output schema of the projection are same, and
  • all projection expressions are either Column or Literal