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EmbeddedProjection

datafusion_physical_plan::projection

Trait EmbeddedProjection 

Source 
pub trait EmbeddedProjection: ExecutionPlan + Sized {
    // Required method
    fn with_projection(&self, projection: Option<Vec<usize>>) -> Result<Self>;
}
Expand description

Trait for execution plans that can embed a projection, avoiding a separate ProjectionExec wrapper.

§Empty projections

Some(vec![]) is a valid projection that produces zero output columns while preserving the correct row count. Implementors must ensure that runtime batch construction still returns batches with the right number of rows even when no columns are selected (e.g. for SELECT count(1) … JOIN …).

Required Methods§

Source

fn with_projection(&self, projection: Option<Vec<usize>>) -> Result<Self>

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§