Class RelOptRuleOperand

  • Direct Known Subclasses:
    RelOptRule.ConverterRelOptRuleOperand

    public class RelOptRuleOperand
    extends java.lang.Object
    Operand that determines whether a RelOptRule can be applied to a particular expression.

    For example, the rule to pull a filter up from the left side of a join takes operands: Join(Filter, Any).

    Note that children means different things if it is empty or it is null: Join(Filter (), Any) means that, to match the rule, Filter must have no operands.