Package org.apache.calcite.plan

Class MulticastRelOptListener

  • All Implemented Interfaces:
    java.util.EventListener, RelOptListener
    public class MulticastRelOptListener
extends java.lang.Object
implements RelOptListener
    MulticastRelOptListener implements the RelOptListener interface by forwarding events on to a collection of other listeners.

    • Field Detail

    • Constructor Detail

      • MulticastRelOptListener

        public MulticastRelOptListener()
        Creates a new empty multicast listener.

    • Method Detail

      • addListener

        public void addListener​(RelOptListener listener)
        Adds a listener which will receive multicast events.
        Parameters:
        listener - listener to add

      • relEquivalenceFound

        public void relEquivalenceFound​(RelOptListener.RelEquivalenceEvent event)
        Description copied from interface: RelOptListener
        Notifies this listener that a relational expression has been registered with a particular equivalence class after an equivalence has been either detected or asserted. Equivalence classes may be either logical (all expressions which yield the same result set) or physical (all expressions which yield the same result set with a particular calling convention).
        Specified by:
        relEquivalenceFound in interface RelOptListener
        Parameters:
        event - details about the event

      • ruleAttempted

        public void ruleAttempted​(RelOptListener.RuleAttemptedEvent event)
        Description copied from interface: RelOptListener
        Notifies this listener that an optimizer rule is being applied to a particular relational expression. This rule is called twice; once before the rule is invoked, and once after. Note that the rel attribute of the event is always the old expression.
        Specified by:
        ruleAttempted in interface RelOptListener
        Parameters:
        event - details about the event

      • ruleProductionSucceeded

        public void ruleProductionSucceeded​(RelOptListener.RuleProductionEvent event)
        Description copied from interface: RelOptListener
        Notifies this listener that an optimizer rule has been successfully applied to a particular relational expression, resulting in a new equivalent expression (relEquivalenceFound will also be called unless the new expression is identical to an existing one). This rule is called twice; once before registration of the new rel, and once after. Note that the rel attribute of the event is always the new expression; to get the old expression, use event.getRuleCall().rels[0].
        Specified by:
        ruleProductionSucceeded in interface RelOptListener
        Parameters:
        event - details about the event

      • relChosen

        public void relChosen​(RelOptListener.RelChosenEvent event)
        Description copied from interface: RelOptListener
        Notifies this listener that a relational expression has been chosen as part of the final implementation of the query plan. After the plan is copmlete, this is called one more time with null for the rel.
        Specified by:
        relChosen in interface RelOptListener
        Parameters:
        event - details about the event