Package org.apache.calcite.rel.metadata

Interface BuiltInMetadata.Selectivity

All Superinterfaces:
Metadata
Enclosing class:
BuiltInMetadata
public static interface BuiltInMetadata.Selectivity extends Metadata
Metadata about the selectivity of a predicate.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    BuiltInMetadata.Selectivity.Handler
    Handler API.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final MetadataDef<BuiltInMetadata.Selectivity>
    DEF
     

  • Method Summary

    Modifier and Type
    Method
    Description
    @Nullable Double
    getSelectivity(@Nullable RexNode predicate)
    Estimates the percentage of an expression's output rows which satisfy a given predicate.

    Methods inherited from interface org.apache.calcite.rel.metadata.Metadata

    rel

  • Field Details

  • Method Details

    • getSelectivity

      @Nullable Double getSelectivity(@Nullable RexNode predicate)
      Estimates the percentage of an expression's output rows which satisfy a given predicate. Returns null to indicate that no reliable estimate can be produced.
      Parameters:
      predicate - predicate whose selectivity is to be estimated against rel's output
      Returns:
      estimated selectivity (between 0.0 and 1.0), or null if no reliable estimate can be determined