Module movement

Transformations that move relation expressions up (lifting) and down (pushdown) the tree.

Transformations inhabiting this module can be used both as part of a normalization pass and as a stand-alone optimization. The former is usually achieved by implementing a more restricted form of the latter.

Modules

• projection_lifting 🔒
  Hoist projections through operators.
• projection_pushdown 🔒
  Pushes column removal down through other operators.

Structs

• ProjectionLifting
  Hoist projections through operators.
• ProjectionPushdown
  Pushes projections down through other operators.