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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.drill.exec.planner.physical;
import java.io.IOException;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.apache.drill.common.exceptions.DrillRuntimeException;
import org.apache.drill.common.exceptions.ExecutionSetupException;
import org.apache.drill.exec.physical.base.GroupScan;
import org.apache.drill.exec.physical.base.PhysicalOperator;
import org.apache.drill.exec.physical.base.ScanStats;
import org.apache.drill.exec.planner.cost.DrillCostBase.DrillCostFactory;
import org.apache.drill.exec.planner.physical.visitor.PrelVisitor;
import org.apache.drill.exec.record.BatchSchema.SelectionVectorMode;
import org.eigenbase.rel.AbstractRelNode;
import org.eigenbase.rel.RelNode;
import org.eigenbase.rel.RelWriter;
import org.eigenbase.relopt.RelOptCluster;
import org.eigenbase.relopt.RelOptCost;
import org.eigenbase.relopt.RelOptPlanner;
import org.eigenbase.relopt.RelTraitSet;
import org.eigenbase.reltype.RelDataType;
public class ScanPrel extends AbstractRelNode implements DrillScanPrel {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory
.getLogger(ScanPrel.class);
protected final GroupScan groupScan;
private final RelDataType rowType;
public ScanPrel(RelOptCluster cluster, RelTraitSet traits,
GroupScan groupScan, RelDataType rowType) {
super(cluster, traits);
this.groupScan = getCopy(groupScan);
this.rowType = rowType;
}
@Override
public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) {
return new ScanPrel(this.getCluster(), traitSet, groupScan,
this.rowType);
}
@Override
protected Object clone() throws CloneNotSupportedException {
return new ScanPrel(this.getCluster(), this.getTraitSet(), getCopy(groupScan),
this.rowType);
}
private static GroupScan getCopy(GroupScan scan){
try {
return (GroupScan) scan.getNewWithChildren((List<PhysicalOperator>) (Object) Collections.emptyList());
} catch (ExecutionSetupException e) {
throw new DrillRuntimeException("Unexpected failure while coping node.", e);
}
}
@Override
public PhysicalOperator getPhysicalOperator(PhysicalPlanCreator creator)
throws IOException {
return creator.addMetadata(this, groupScan);
}
@Override
public GroupScan getGroupScan() {
return groupScan;
}
public static ScanPrel create(RelNode old, RelTraitSet traitSets,
GroupScan scan, RelDataType rowType) {
return new ScanPrel(old.getCluster(), traitSets, getCopy(scan), rowType);
}
@Override
public RelWriter explainTerms(RelWriter pw) {
return super.explainTerms(pw).item("groupscan", groupScan.getDigest());
}
@Override
public RelDataType deriveRowType() {
return this.rowType;
}
@Override
public double getRows() {
return this.groupScan.getScanStats().getRecordCount();
}
@Override
public RelOptCost computeSelfCost(RelOptPlanner planner) {
ScanStats stats = this.groupScan.getScanStats();
int columnCount = this.getRowType().getFieldCount();
if(PrelUtil.getSettings(getCluster()).useDefaultCosting()) {
return planner.getCostFactory().makeCost(stats.getRecordCount() * columnCount, stats.getCpuCost(), stats.getDiskCost());
}
// double rowCount = RelMetadataQuery.getRowCount(this);
double rowCount = stats.getRecordCount();
double cpuCost = rowCount * columnCount; // for now, assume cpu cost is proportional to row count.
// Even though scan is reading from disk, in the currently generated plans all plans will
// need to read the same amount of data, so keeping the disk io cost 0 is ok for now.
// In the future we might consider alternative scans that go against projections or
// different compression schemes etc that affect the amount of data read. Such alternatives
// would affect both cpu and io cost.
double ioCost = 0;
DrillCostFactory costFactory = (DrillCostFactory)planner.getCostFactory();
return costFactory.makeCost(rowCount, cpuCost, ioCost, 0);
}
@Override
public Iterator<Prel> iterator() {
return Collections.emptyIterator();
}
@Override
public <T, X, E extends Throwable> T accept(PrelVisitor<T, X, E> logicalVisitor, X value) throws E {
return logicalVisitor.visitScan(this, value);
}
@Override
public SelectionVectorMode[] getSupportedEncodings() {
return SelectionVectorMode.DEFAULT;
}
@Override
public SelectionVectorMode getEncoding() {
return SelectionVectorMode.NONE;
}
@Override
public boolean needsFinalColumnReordering() {
return true;
}
}