DerivePruneCols returns the subset of the given expression's output columns that are candidates for pruning.

DeriveRejectNullCols returns the set of columns that are candidates for NULL rejection filter pushdown.

CustomFuncs contains all the custom match and replace functions used by the normalization rules.

Factory constructs a normalized expression tree within the memo.

AppliedRuleFunc defines the callback function for the NotifyOnAppliedRule event supported by the optimizer and factory.

MatchedRuleFunc defines the callback function for the NotifyOnMatchedRule event supported by the optimizer and factory.

ReplaceFunc is the callback function passed to the Factory.Replace method.