Convert2Group converts a logical plan to a Group.

Convert2GroupExpr converts a logical plan to a GroupExpr.

NewExprIterFromGroupElem creates the iterator on the Group Element.

NewGroupExpr creates a GroupExpr based on a logical plan node.

NewGroupWithSchema creates a new Group with given schema.

ExprIter enumerates all the equivalent expressions in the Group according to the expression pattern.

Group is short for expression Group, which is used to store all the logically equivalent expressions.

GroupExpr is used to store all the logically equivalent expressions which have the same root operator.

Implementation defines the interface for cost of physical plan.

ExploreMark is uses to mark whether a Group or GroupExpr has been fully explored by a transformation rule batch.