org.apache.hadoop.hive.ql.optimizer.calcite.rules.HiveCardinalityPreservingJoinRule Maven / Gradle / Ivy
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package org.apache.hadoop.hive.ql.optimizer.calcite.rules;
import org.apache.calcite.plan.RelOptCost;
import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.plan.RelOptUtil;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.metadata.JaninoRelMetadataProvider;
import org.apache.calcite.rel.metadata.RelMetadataQuery;
import org.apache.hadoop.hive.ql.optimizer.calcite.HiveTezModelRelMetadataProvider;
import org.apache.hadoop.hive.ql.optimizer.calcite.HiveRelShuttleImpl;
import org.apache.hadoop.hive.ql.optimizer.calcite.cost.HiveDefaultCostModel;
import org.apache.hadoop.hive.ql.optimizer.calcite.reloperators.HiveJoin;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Rule to trigger {@link HiveCardinalityPreservingJoinOptimization} on top of the plan.
*/
public class HiveCardinalityPreservingJoinRule extends HiveFieldTrimmerRule {
private static final Logger LOG = LoggerFactory.getLogger(HiveCardinalityPreservingJoinRule.class);
private final double factor;
public HiveCardinalityPreservingJoinRule(double factor) {
super(false, "HiveCardinalityPreservingJoinRule");
this.factor = Math.max(factor, 0.0);
}
@Override
protected RelNode trim(RelOptRuleCall call, RelNode node) {
RelNode optimized = new HiveCardinalityPreservingJoinOptimization().trim(call.builder(), node);
if (optimized == node) {
return node;
}
RelNode chosen = choosePlan(node, optimized);
new JoinAlgorithmSetter().visit(chosen);
return chosen;
}
private RelNode choosePlan(RelNode node, RelNode optimized) {
JaninoRelMetadataProvider original = RelMetadataQuery.THREAD_PROVIDERS.get();
try {
RelMetadataQuery.THREAD_PROVIDERS.set(
HiveTezModelRelMetadataProvider.DEFAULT);
node.getCluster().invalidateMetadataQuery();
RelMetadataQuery metadataQuery = RelMetadataQuery.instance();
RelOptCost optimizedCost = metadataQuery.getCumulativeCost(optimized);
RelOptCost originalCost = metadataQuery.getCumulativeCost(node);
originalCost = originalCost.multiplyBy(factor);
LOG.debug("Original plan cost {} vs Optimized plan cost {}", originalCost, optimizedCost);
if (optimizedCost.isLt(originalCost)) {
if (LOG.isDebugEnabled()) {
LOG.debug("Plan after:\n" + RelOptUtil.toString(optimized));
}
return optimized;
}
return node;
}
finally {
node.getCluster().invalidateMetadataQuery();
RelMetadataQuery.THREAD_PROVIDERS.set(original);
}
}
private static class JoinAlgorithmSetter extends HiveRelShuttleImpl {
@Override
public RelNode visit(HiveJoin join) {
join.setJoinAlgorithm(HiveDefaultCostModel.DefaultJoinAlgorithm.INSTANCE);
return super.visit(join);
}
}
}