How to use

ChainedRelMetadataProvider

in

org.apache.calcite.rel.metadata

public RelMetadataProvider getMetadataProvider() {
 return ChainedRelMetadataProvider.of(
       ImmutableList.of(
         ReflectiveRelMetadataProvider.reflectiveSource(this,
           BuiltInMethod.NON_CUMULATIVE_COST.method),
         RelMdPercentageOriginalRows.SOURCE));
}

/** Creates a chain. */
public static RelMetadataProvider of(List<RelMetadataProvider> list) {
 return new ChainedRelMetadataProvider(ImmutableList.copyOf(list));
}

/** Creates a chain. */
public static RelMetadataProvider of(List<RelMetadataProvider> list) {
 return new ChainedRelMetadataProvider(ImmutableList.copyOf(list));
}

public RelMetadataProvider getMetadataProvider() {
 return ChainedRelMetadataProvider.of(
       ImmutableList.of(
         ReflectiveRelMetadataProvider.reflectiveSource(this,
           BuiltInMethod.NON_CUMULATIVE_COST.method),
         RelMdPercentageOriginalRows.SOURCE));
}

public RelMetadataProvider getMetadataProvider() {
 // Create cost metadata provider
 final HiveCostModel cm;
 if (HiveConf.getVar(this.hiveConf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("tez")
     && HiveConf.getBoolVar(this.hiveConf, HiveConf.ConfVars.HIVE_CBO_EXTENDED_COST_MODEL)) {
  cm = HiveOnTezCostModel.getCostModel(hiveConf);
 } else {
  cm = HiveDefaultCostModel.getCostModel();
 }
 // Get max split size for HiveRelMdParallelism
 final Double maxSplitSize = (double) HiveConf.getLongVar(
     this.hiveConf,
     HiveConf.ConfVars.MAPREDMAXSPLITSIZE);
 // Return MD provider
 return ChainedRelMetadataProvider.of(ImmutableList
     .of(
         HiveRelMdDistinctRowCount.SOURCE,
         new HiveRelMdCost(cm).getMetadataProvider(),
         HiveRelMdSelectivity.SOURCE,
         HiveRelMdRowCount.SOURCE,
         HiveRelMdUniqueKeys.SOURCE,
         HiveRelMdColumnUniqueness.SOURCE,
         HiveRelMdSize.SOURCE,
         HiveRelMdMemory.SOURCE,
         new HiveRelMdParallelism(maxSplitSize).getMetadataProvider(),
         HiveRelMdDistribution.SOURCE,
         HiveRelMdCollation.SOURCE,
         HiveRelMdPredicates.SOURCE,
         DefaultRelMetadataProvider.INSTANCE));
}

public RelMetadataProvider getMetadataProvider() {
 // Create cost metadata provider
 final HiveCostModel cm;
 if (HiveConf.getVar(this.hiveConf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("tez")
     && HiveConf.getBoolVar(this.hiveConf, HiveConf.ConfVars.HIVE_CBO_EXTENDED_COST_MODEL)) {
  cm = HiveOnTezCostModel.getCostModel(hiveConf);
 } else {
  cm = HiveDefaultCostModel.getCostModel();
 }
 // Get max split size for HiveRelMdParallelism
 final Double maxSplitSize = (double) HiveConf.getLongVar(
     this.hiveConf,
     HiveConf.ConfVars.MAPREDMAXSPLITSIZE);
 // Return MD provider
 return ChainedRelMetadataProvider.of(ImmutableList
     .of(
         HiveRelMdDistinctRowCount.SOURCE,
         new HiveRelMdCost(cm).getMetadataProvider(),
         HiveRelMdSelectivity.SOURCE,
         HiveRelMdRowCount.SOURCE,
         HiveRelMdUniqueKeys.SOURCE,
         HiveRelMdSize.SOURCE,
         HiveRelMdMemory.SOURCE,
         new HiveRelMdParallelism(maxSplitSize).getMetadataProvider(),
         HiveRelMdDistribution.SOURCE,
         HiveRelMdCollation.SOURCE,
         HiveRelMdPredicates.SOURCE,
         DefaultRelMetadataProvider.INSTANCE));
}

RelMetadataProvider chainedProvider = ChainedRelMetadataProvider.of(list);
optCluster.setMetadataProvider(new CachingRelMetadataProvider(chainedProvider, hepPlanner));

RelMetadataProvider chainedProvider = ChainedRelMetadataProvider.of(list);
optCluster.setMetadataProvider(new CachingRelMetadataProvider(chainedProvider, hepPlanner));

list.add(mdProvider);
planner.registerMetadataProviders(list);
RelMetadataProvider chainedProvider = ChainedRelMetadataProvider.of(list);
basePlan.getCluster().setMetadataProvider(
  new CachingRelMetadataProvider(chainedProvider, planner));

list.add(mdProvider);
planner.registerMetadataProviders(list);
RelMetadataProvider chainedProvider = ChainedRelMetadataProvider.of(list);
basePlan.getCluster().setMetadataProvider(
  new CachingRelMetadataProvider(chainedProvider, planner));

list.add(mdProvider.getMetadataProvider());
planner.registerMetadataProviders(list);
RelMetadataProvider chainedProvider = ChainedRelMetadataProvider.of(list);

public RelMetadataProvider getMetadataProvider() {
 return ChainedRelMetadataProvider.of(
       ImmutableList.of(
         ReflectiveRelMetadataProvider.reflectiveSource(this,
           BuiltInMethod.NON_CUMULATIVE_COST.method),
         RelMdPercentageOriginalRows.SOURCE));
}

 public RelNode run(RelOptPlanner planner, RelNode rel,
           RelTraitSet requiredOutputTraits,
           List<RelOptMaterialization> materializations,
           List<RelOptLattice> lattices) {
  final HepPlanner hepPlanner = new HepPlanner(hepProgram,
    null, noDag, null, RelOptCostImpl.FACTORY);
  List<RelMetadataProvider> list = Lists.newArrayList();
  if (metadataProvider != null) {
   list.add(metadataProvider);
  }
  hepPlanner.registerMetadataProviders(list);
  RelMetadataProvider plannerChain =
    ChainedRelMetadataProvider.of(list);
  rel.getCluster().setMetadataProvider(plannerChain);
  hepPlanner.setRoot(rel);
  return hepPlanner.findBestExp();
 }
};

/** Creates a program that executes a {@link HepProgram}. */
public static Program of(final HepProgram hepProgram, final boolean noDag,
  final RelMetadataProvider metadataProvider) {
 return (planner, rel, requiredOutputTraits, materializations, lattices) -> {
  final HepPlanner hepPlanner = new HepPlanner(hepProgram,
    null, noDag, null, RelOptCostImpl.FACTORY);
  List<RelMetadataProvider> list = new ArrayList<>();
  if (metadataProvider != null) {
   list.add(metadataProvider);
  }
  hepPlanner.registerMetadataProviders(list);
  RelMetadataProvider plannerChain =
    ChainedRelMetadataProvider.of(list);
  rel.getCluster().setMetadataProvider(plannerChain);
  hepPlanner.setRoot(rel);
  return hepPlanner.findBestExp();
 };
}

/** Creates a program that executes a {@link HepProgram}. */
public static Program of(final HepProgram hepProgram, final boolean noDag,
  final RelMetadataProvider metadataProvider) {
 return (planner, rel, requiredOutputTraits, materializations, lattices) -> {
  final HepPlanner hepPlanner = new HepPlanner(hepProgram,
    null, noDag, null, RelOptCostImpl.FACTORY);
  List<RelMetadataProvider> list = new ArrayList<>();
  if (metadataProvider != null) {
   list.add(metadataProvider);
  }
  hepPlanner.registerMetadataProviders(list);
  RelMetadataProvider plannerChain =
    ChainedRelMetadataProvider.of(list);
  rel.getCluster().setMetadataProvider(plannerChain);
  hepPlanner.setRoot(rel);
  return hepPlanner.findBestExp();
 };
}

@Test public void testBrokenCustomProvider() {
 final List<String> buf = new ArrayList<>();
 ColTypeImpl.THREAD_LIST.set(buf);
 final String sql = "select deptno, count(*) from emp where deptno > 10 "
   + "group by deptno having count(*) = 0";
 final RelRoot root = tester
   .withClusterFactory(cluster -> {
    cluster.setMetadataProvider(
      ChainedRelMetadataProvider.of(
        ImmutableList.of(BrokenColTypeImpl.SOURCE,
          cluster.getMetadataProvider())));
    return cluster;
   })
   .convertSqlToRel(sql);
 final RelNode rel = root.rel;
 assertThat(rel, instanceOf(LogicalFilter.class));
 final MyRelMetadataQuery mq = new MyRelMetadataQuery();
 try {
  assertThat(colType(mq, rel, 0), equalTo("DEPTNO-rel"));
  fail("expected error");
 } catch (IllegalArgumentException e) {
  final String value = "No handler for method [public abstract java.lang.String "
    + "org.apache.calcite.test.RelMetadataTest$ColType.getColType(int)] "
    + "applied to argument of type [interface org.apache.calcite.rel.RelNode]; "
    + "we recommend you create a catch-all (RelNode) handler";
  assertThat(e.getMessage(), is(value));
 }
}

public RelMetadataProvider getMetadataProvider() {
 // Create cost metadata provider
 final HiveCostModel cm;
 if (HiveConf.getVar(this.hiveConf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("tez")
     && HiveConf.getBoolVar(this.hiveConf, HiveConf.ConfVars.HIVE_CBO_EXTENDED_COST_MODEL)) {
  cm = HiveOnTezCostModel.getCostModel(hiveConf);
 } else {
  cm = HiveDefaultCostModel.getCostModel();
 }
 // Get max split size for HiveRelMdParallelism
 final Double maxSplitSize = (double) HiveConf.getLongVar(
     this.hiveConf,
     HiveConf.ConfVars.MAPREDMAXSPLITSIZE);
 // Return MD provider
 return ChainedRelMetadataProvider.of(ImmutableList
     .of(
         HiveRelMdDistinctRowCount.SOURCE,
         new HiveRelMdCost(cm).getMetadataProvider(),
         HiveRelMdSelectivity.SOURCE,
         HiveRelMdRowCount.SOURCE,
         HiveRelMdUniqueKeys.SOURCE,
         HiveRelMdSize.SOURCE,
         HiveRelMdMemory.SOURCE,
         new HiveRelMdParallelism(maxSplitSize).getMetadataProvider(),
         HiveRelMdDistribution.SOURCE,
         HiveRelMdCollation.SOURCE,
         new DefaultRelMetadataProvider()));
}

@Test public void testBrokenCustomProvider() {
 final List<String> buf = new ArrayList<>();
 ColTypeImpl.THREAD_LIST.set(buf);
 final String sql = "select deptno, count(*) from emp where deptno > 10 "
   + "group by deptno having count(*) = 0";
 final RelRoot root = tester
   .withClusterFactory(cluster -> {
    cluster.setMetadataProvider(
      ChainedRelMetadataProvider.of(
        ImmutableList.of(BrokenColTypeImpl.SOURCE,
          cluster.getMetadataProvider())));
    return cluster;
   })
   .convertSqlToRel(sql);
 final RelNode rel = root.rel;
 assertThat(rel, instanceOf(LogicalFilter.class));
 final MyRelMetadataQuery mq = new MyRelMetadataQuery();
 try {
  assertThat(colType(mq, rel, 0), equalTo("DEPTNO-rel"));
  fail("expected error");
 } catch (IllegalArgumentException e) {
  final String value = "No handler for method [public abstract java.lang.String "
    + "org.apache.calcite.test.RelMetadataTest$ColType.getColType(int)] "
    + "applied to argument of type [interface org.apache.calcite.rel.RelNode]; "
    + "we recommend you create a catch-all (RelNode) handler";
  assertThat(e.getMessage(), is(value));
 }
}

ChainedRelMetadataProvider.of(
  ImmutableList.of(
    ReflectiveRelMetadataProvider.reflectiveSource(

ChainedRelMetadataProvider.of(
  ImmutableList.of(
    ReflectiveRelMetadataProvider.reflectiveSource(