Interface RelOptNode

    • Method Detail

      • getId

        int getId()
        Returns the ID of this relational expression, unique among all relational expressions created since the server was started.
        Returns:
        Unique ID
      • getDigest

        java.lang.String getDigest()
        Returns a string which concisely describes the definition of this relational expression. Two relational expressions are equivalent if their digests and getRowType() are the same.

        The digest does not contain the relational expression's identity -- that would prevent similar relational expressions from ever comparing equal -- but does include the identity of children (on the assumption that children have already been normalized).

        If you want a descriptive string which contains the identity, call Object.toString(), which always returns "rel#{id}:{digest}".

        Returns:
        Digest of this RelNode
      • getTraitSet

        RelTraitSet getTraitSet()
        Retrieves this RelNode's traits. Note that although the RelTraitSet returned is modifiable, it must not be modified during optimization. It is legal to modify the traits of a RelNode before or after optimization, although doing so could render a tree of RelNodes unimplementable. If a RelNode's traits need to be modified during optimization, clone the RelNode and change the clone's traits.
        Returns:
        this RelNode's trait set
      • getDescription

        java.lang.String getDescription()
        Returns a string which describes the relational expression and, unlike getDigest(), also includes the identity. Typically returns "rel#{id}:{digest}".
        Returns:
        String which describes the relational expression and, unlike getDigest(), also includes the identity
      • getInputs

        java.util.List<? extends RelOptNode> getInputs()
        Returns an array of this relational expression's inputs. If there are no inputs, returns an empty list, not null.
        Returns:
        Array of this relational expression's inputs
      • getCluster

        RelOptCluster getCluster()
        Returns the cluster this relational expression belongs to.
        Returns:
        cluster