Package org.apache.calcite.rel.metadata

Class CachingRelMetadataProvider

java.lang.Object
org.apache.calcite.rel.metadata.CachingRelMetadataProvider
All Implemented Interfaces:
RelMetadataProvider
@Deprecated public class CachingRelMetadataProvider extends Object implements RelMetadataProvider
Deprecated.
Implementation of the RelMetadataProvider interface that caches results from an underlying provider.

  • Constructor Details

  • Method Details

    • apply

      @Deprecated public <@Nullable M extends @Nullable Metadata> @Nullable UnboundMetadata<M> apply(Class<? extends RelNode> relClass, Class<? extends @Nullable M> metadataClass)
      Deprecated.
      Description copied from interface: RelMetadataProvider
      Retrieves metadata of a particular type and for a particular sub-class of relational expression.

      The object returned is a function. It can be applied to a relational expression of the given type to create a metadata object.

      For example, you might call

       RelMetadataProvider provider;
 LogicalFilter filter;
 RexNode predicate;
 Function<RelNode, Metadata> function =
   provider.apply(LogicalFilter.class, Selectivity.class};
 Selectivity selectivity = function.apply(filter);
 Double d = selectivity.selectivity(predicate);
      Specified by:
      apply in interface RelMetadataProvider
      Parameters:
      relClass - Type of relational expression
      metadataClass - Type of metadata
      Returns:
      Function that will field a metadata instance; or null if this provider cannot supply metadata of this type

    • handlers

      @Deprecated public <M extends Metadata> com.google.common.collect.Multimap<Method,MetadataHandler<M>> handlers(MetadataDef<M> def)
      Deprecated.
      Specified by:
      handlers in interface RelMetadataProvider

    • handlers

      public List<MetadataHandler<?>> handlers(Class<? extends MetadataHandler<?>> handlerClass)
      Deprecated.
      Description copied from interface: RelMetadataProvider
      Retrieves a list of MetadataHandler for implements a particular MetadataHandler.class. The resolution order is specificity of the relNode class, with preference given to handlers that occur earlier in the list. For instance, given a return list of {A, B, C} where A implements RelNode and Scan, B implements Scan, and C implements LogicalScan and Filter. Scan dispatches to a.method(Scan) LogicalFilter dispatches to c.method(Filter). LogicalScan dispatches to c.method(LogicalScan). Aggregate dispatches to a.method(RelNode). The behavior is undefined if the class hierarchy for dispatching is not a tree.
      Specified by:
      handlers in interface RelMetadataProvider