Module utils

Utility functions leveraged by the query optimizer rules

Structs

NamePreserver

Re-export of NamesPreserver for backwards compatibility, as it was initially placed here and then moved elsewhere. Handles ensuring the name of rewritten expressions is not changed.

Functions

is_restrict_null_predicate

Determine whether a predicate can restrict NULLs. e.g. c0 > 8 return true; c0 IS NULL return false.

log_plan

Log the plan in debug/tracing mode after some part of the optimizer runs

optimize_childrenDeprecated

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.