Class RelSubset

  • All Implemented Interfaces:
    java.lang.Cloneable, RelOptNode, RelNode

    public class RelSubset
    extends AbstractRelNode
    Subset of an equivalence class where all relational expressions have the same physical properties.

    Physical properties are instances of the RelTraitSet, and consist of traits such as calling convention and collation (sort-order).

    For some traits, a relational expression can have more than one instance. For example, R can be sorted on both [X] and [Y, Z]. In which case, R would belong to the sub-sets for [X] and [Y, Z]; and also the leading edges [Y] and [].

    See Also:
    RelNode, RelSet, RelTrait
    • Field Detail

      • LOGGER

        private static final org.slf4j.Logger LOGGER
      • bestCost

        RelOptCost bestCost
        cost of best known plan (it may have improved since)
      • set

        final RelSet set
        The set this subset belongs to.
      • best

        RelNode best
        best known plan
      • timestamp

        long timestamp
        Timestamp for metadata validity
      • boosted

        boolean boosted
        Flag indicating whether this RelSubset's importance was artificially boosted.