Module mz_expr::relation::canonicalize

Utility functions to transform parts of a single MirRelationExpr into canonical form.

Functions

• canonicalize_equivalence_classes
  Canonicalize only the equivalence classes of a join.
• canonicalize_equivalences
  Canonicalize equivalence classes of a join and expressions contained in them.
• canonicalize_predicates
  Canonicalize predicates of a filter.
• compare_predicates 🔒
  Comparison method for sorting predicates by their complexity, measured by the total number of non-literal expression nodes within the expression.
• flat_map_modify 🔒
  Applies a flat_map on a Vec, and overwrites the vec with the result.
• get_canonicalizer_map
  For each equivalence class, it finds the simplest expression, which will be the canonical one. Returns a Map that maps from each expression in each equivalence class to the canonical expression in the same equivalence class.
• is_not_null 🔒
  Returns the inner operand if the given predicate is an IS NOT NULL expression.
• is_null_rejecting_predicate 🔒
  Whether the given predicate evaluates to NULL when the given operand expression is NULL.
• propagates_null_from_subexpression 🔒
• rank_complexity 🔒
  Gives a relative complexity ranking for an expression. Higher numbers mean greater complexity.
• replace_subexpr_and_reduce 🔒
  Replace any matching subexpressions in predicate, and if predicate has changed, reduce it. Return whether predicate has changed.