org.apache.hadoop.hive.ql.optimizer.ppr.OpProcFactory Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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package org.apache.hadoop.hive.ql.optimizer.ppr;
import org.apache.hadoop.hive.ql.exec.FilterOperator;
import org.apache.hadoop.hive.ql.exec.TableScanOperator;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.lib.NodeProcessor;
import org.apache.hadoop.hive.ql.lib.NodeProcessorCtx;
import org.apache.hadoop.hive.ql.optimizer.PrunerOperatorFactory;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.plan.ExprNodeDesc;
/**
* Operator factory for partition pruning processing of operator graph We find
* all the filter operators that appear just beneath the table scan operators.
* We then pass the filter to the partition pruner to construct a pruner for
* that table alias and store a mapping from the table scan operator to that
* pruner. We call that pruner later during plan generation.
*
*
* Refactor:
* Move main logic to PrunerOperatorFactory. OpProcFactory extends it to reuse logic.
*
* Any other pruner can reuse it by creating a class extending from PrunerOperatorFactory.
*
* Only specific logic is in generatePredicate(..) which is in its own class like OpProcFactory.
*/
public final class OpProcFactory extends PrunerOperatorFactory {
/**
* Determines the partition pruner for the filter. This is called only when
* the filter follows a table scan operator.
*/
public static class FilterPPR extends FilterPruner {
@Override
protected void generatePredicate(NodeProcessorCtx procCtx, FilterOperator fop,
TableScanOperator top) throws SemanticException, UDFArgumentException {
OpWalkerCtx owc = (OpWalkerCtx) procCtx;
// Otherwise this is not a sampling predicate and we need to
ExprNodeDesc predicate = fop.getConf().getPredicate();
String alias = top.getConf().getAlias();
// Generate the partition pruning predicate
ExprNodeDesc ppr_pred = ExprProcFactory.genPruner(alias, predicate);
// Add the pruning predicate to the table scan operator
addPruningPred(owc.getOpToPartPruner(), top, ppr_pred);
}
}
public static NodeProcessor getFilterProc() {
return new FilterPPR();
}
private OpProcFactory() {
// prevent instantiation
}
}