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.

alias_cols

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_cols

Merge and deduplicate two sets Column slices

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.

split_conjunction

converts “A AND B AND C” => [A, B, C]

swap_table

Change the relation on a slice of Columns

verify_not_disjunction

Recursively scans a slice of expressions for any Or operators