Module datafusion_optimizer::utils

Collection of utility functions that are leveraged by the query optimizer rules

Functions

• add_filter
  returns a new LogicalPlan that wraps plan in a LogicalPlan::Filter with its predicate be all predicates ANDed.
• conjunction
  Combines an array of filter expressions into a single filter expression consisting of the input filter expressions joined with logical AND.
• disjunction
  Combines an array of filter expressions into a single filter expression consisting of the input filter expressions joined with logical OR.
• exprs_to_join_cols
  Extracts correlating columns from expressions
• find_join_exprs
  Looks for correlating expressions: equality expressions with one field from the subquery, and one not in the subquery (closed upon from outer scope)
• merge_schema
  merge inputs schema into a single schema.
• only_or_err
  Returns the first (and only) element in a slice, or an error
• optimize_children
  Convenience rule for writing optimizers: recursively invoke optimize on plan’s children and then return a node of the same type. Useful for optimizer rules which want to leave the type of plan unchanged but still apply to the children. This also handles the case when the plan is a LogicalPlan::Explain.
• rewrite_preserving_name
  Rewrites expr using rewriter, ensuring that the output has the same name as expr prior to rewrite, adding an alias if necessary.
• split_binary
  Splits an binary operator tree Expr such as A <OP> B <OP> C => [A, B, C]
• split_binary_owned
  Splits an owned binary operator tree Expr such as A <OP> B <OP> C => [A, B, C]
• split_conjunction
  Splits a conjunctive Expr such as A AND B AND C => [A, B, C]
• split_conjunction_owned
  Splits an owned conjunctive Expr such as A AND B AND C => [A, B, C]
• unalias
  Recursively un-alias an expressions
• verify_not_disjunction
  Recursively scans a slice of expressions for any Or operators