Module datafusion::physical_optimizer::projection_pushdown

This file implements the ProjectionPushdown physical optimization rule. The function remove_unnecessary_projections tries to push down all projections one by one if the operator below is amenable to this. If a projection reaches a source, it can even disappear from the plan entirely.

Structs

• ProjectionPushdown
  This rule inspects ProjectionExec’s in the given physical plan and tries to remove or swap with its child.

Functions

• remove_unnecessary_projections
  This function checks if plan is a ProjectionExec, and inspects its input(s) to test whether it can push plan under its input(s). This function will operate on the entire tree and may ultimately remove plan entirely by leveraging source providers with built-in projection capabilities.