Module mz_transform::canonicalization

Transformations that bring relation expressions to their canonical form.

This is achieved by:

1. Bringing enclosed scalar expressions to a canonical form,
2. Converting / peeling off part of the enclosing relation expression into another relation expression that can represent the same concept.

Modules

• flatmap_to_map 🔒
  Turns FlatMap into Map if only one row is produced by flatmap.
• projection_extraction 🔒
  Transform column references in a Map into a Project.
• topk_elision 🔒
  Remove TopK operators with both an offset of zero and no limit.

Structs

• FlatMapToMap
  Turns FlatMap into Map if only one row is produced by flatmap.
• ProjectionExtraction
  Transform column references in a Map into a Project, or repeated aggregations in a Reduce into a Project.
• ReduceScalars
  A transform that visits each AST node and reduces scalar expressions.
• TopKElision
  Remove TopK operators with both an offset of zero and no limit.