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Merged
JackieTien97 merged 3 commits into from
Jun 3, 2026
Merged

Remove useless ProjectNode after SortElimination #17806

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2aac4ae
fix
Wei-hao-Li Jun 1, 2026
2dafe7f
fix
Wei-hao-Li Jun 1, 2026
9ea7439
fix CI
Wei-hao-Li Jun 2, 2026
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54 changes: 51 additions & 3 deletions ...he/iotdb/db/queryengine/plan/relational/planner/iterative/rule/PruneTableScanColumns.java
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,9 @@
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.AggregationTableScanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.DeviceTableScanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.InformationSchemaTableScanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.TreeAlignedDeviceViewScanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.TreeDeviceViewScanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.TreeNonAlignedDeviceViewScanNode;

import java.util.ArrayList;
import java.util.LinkedHashMap;
Expand All @@ -55,7 +57,7 @@
return pruneColumns(node, referencedOutputs);
}

public static Optional<PlanNode> pruneColumns(TableScanNode node, Set<Symbol> referencedOutputs) {

Check failure on line 60 in iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/iterative/rule/PruneTableScanColumns.java

View check run for this annotation

SonarQubeCloud / SonarCloud Code Analysis

Refactor this method to reduce its Cognitive Complexity from 16 to the 15 allowed. 


See more on https://sonarcloud.io/project/issues?id=apache_iotdb&issues=AZ6Ggkvk0TdFlJBFFmea&open=AZ6Ggkvk0TdFlJBFFmea&pullRequest=17806
if (node instanceof AggregationTableScanNode) {
return Optional.empty();
}
Expand Down Expand Up @@ -91,7 +93,51 @@
.forEach(
symbol -> newAssignments.put(symbol, node.getAssignments().get(symbol))));

if (node instanceof TreeDeviceViewScanNode) {
if (node instanceof TreeAlignedDeviceViewScanNode) {
TreeAlignedDeviceViewScanNode treeDeviceViewScanNode =
(TreeAlignedDeviceViewScanNode) deviceTableScanNode;
TreeAlignedDeviceViewScanNode prunedNode =
new TreeAlignedDeviceViewScanNode(
deviceTableScanNode.getPlanNodeId(),
deviceTableScanNode.getQualifiedObjectName(),
newOutputs,
newAssignments,
deviceTableScanNode.getDeviceEntries(),
deviceTableScanNode.getTagAndAttributeIndexMap(),
deviceTableScanNode.getScanOrder(),
deviceTableScanNode.getTimePredicate().orElse(null),
deviceTableScanNode.getPushDownPredicate(),
deviceTableScanNode.getPushDownLimit(),
deviceTableScanNode.getPushDownOffset(),
deviceTableScanNode.isPushLimitToEachDevice(),
deviceTableScanNode.containsNonAlignedDevice(),
treeDeviceViewScanNode.getTreeDBName(),
treeDeviceViewScanNode.getMeasurementColumnNameMap());
prunedNode.setRegionReplicaSet(deviceTableScanNode.getRegionReplicaSet());
return Optional.of(prunedNode);
} else if (node instanceof TreeNonAlignedDeviceViewScanNode) {
TreeNonAlignedDeviceViewScanNode treeDeviceViewScanNode =
(TreeNonAlignedDeviceViewScanNode) deviceTableScanNode;
TreeNonAlignedDeviceViewScanNode prunedNode =
new TreeNonAlignedDeviceViewScanNode(
deviceTableScanNode.getPlanNodeId(),
deviceTableScanNode.getQualifiedObjectName(),
newOutputs,
newAssignments,
deviceTableScanNode.getDeviceEntries(),
deviceTableScanNode.getTagAndAttributeIndexMap(),
deviceTableScanNode.getScanOrder(),
deviceTableScanNode.getTimePredicate().orElse(null),
deviceTableScanNode.getPushDownPredicate(),
deviceTableScanNode.getPushDownLimit(),
deviceTableScanNode.getPushDownOffset(),
deviceTableScanNode.isPushLimitToEachDevice(),
deviceTableScanNode.containsNonAlignedDevice(),
treeDeviceViewScanNode.getTreeDBName(),
treeDeviceViewScanNode.getMeasurementColumnNameMap());
prunedNode.setRegionReplicaSet(deviceTableScanNode.getRegionReplicaSet());
return Optional.of(prunedNode);
} else if (node instanceof TreeDeviceViewScanNode) {
TreeDeviceViewScanNode treeDeviceViewScanNode =
(TreeDeviceViewScanNode) deviceTableScanNode;
return Optional.of(
Expand All @@ -112,7 +158,7 @@
treeDeviceViewScanNode.getTreeDBName(),
treeDeviceViewScanNode.getMeasurementColumnNameMap()));
} else {
return Optional.of(
DeviceTableScanNode prunedNode =
new DeviceTableScanNode(
deviceTableScanNode.getPlanNodeId(),
deviceTableScanNode.getQualifiedObjectName(),
Expand All @@ -126,7 +172,9 @@
deviceTableScanNode.getPushDownLimit(),
deviceTableScanNode.getPushDownOffset(),
deviceTableScanNode.isPushLimitToEachDevice(),
deviceTableScanNode.containsNonAlignedDevice()));
deviceTableScanNode.containsNonAlignedDevice());
prunedNode.setRegionReplicaSet(deviceTableScanNode.getRegionReplicaSet());
return Optional.of(prunedNode);
}
} else if (node instanceof InformationSchemaTableScanNode) {
// For the convenience of process in execution stage, column-prune for
Expand Down
46 changes: 46 additions & 0 deletions ...rg/apache/iotdb/db/queryengine/plan/relational/planner/optimizations/SortElimination.java
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Original file line number Diff line number Diff line change
Expand Up @@ -25,14 +25,21 @@
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.FillNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.GapFillNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.PatternRecognitionNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.ProjectNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.SortNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.StreamSortNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.ValueFillNode;
import org.apache.iotdb.commons.queryengine.plan.relational.planner.node.WindowNode;
import org.apache.iotdb.db.queryengine.plan.planner.plan.node.PlanVisitor;
import org.apache.iotdb.db.queryengine.plan.relational.planner.iterative.rule.PruneTableScanColumns;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.DeviceTableScanNode;

import com.google.common.collect.ImmutableSet;

import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.Set;

/**
* <b>Optimization phase:</b> Distributed plan planning.
Expand All @@ -42,6 +49,8 @@
* SortNode can be eliminated.
* <li>When order by all IDColumns and time, the SortNode can be eliminated.
* <li>When StreamSortIndex==OrderBy size()-1, remove this StreamSortNode
* <li>After SortNode elimination, visitProject will remove redundant identity ProjectNodes above
* TableScan and pushes column pruning into the scan.
*/
public class SortElimination implements PlanOptimizer {

Expand All @@ -64,6 +73,43 @@ public PlanNode visitPlan(PlanNode node, Context context) {
return newNode;
}

@Override
public PlanNode visitProject(ProjectNode node, Context context) {
Context newContext = new Context();
PlanNode child = node.getChild().accept(this, newContext);
context.setCannotEliminateSort(newContext.cannotEliminateSort);

// Remove useless ProjectNode and prune columns of TableScanNode
return eliminateProjectOverTableScan(node, child)
.orElseGet(() -> node.replaceChildren(Collections.singletonList(child)));
}

private static Optional<PlanNode> eliminateProjectOverTableScan(
ProjectNode project, PlanNode child) {
if (!(child instanceof DeviceTableScanNode) || !project.isIdentity()) {
return Optional.empty();
}

// Notice that SortNode may have been eliminated in TableDistributedPlanGenerator
DeviceTableScanNode tableScan = (DeviceTableScanNode) child;
int projectOutputsSize = project.getOutputSymbols().size();
int scanOutputsSize = tableScan.getOutputSymbols().size();
if (projectOutputsSize > scanOutputsSize) {
return Optional.empty();
}

List<Symbol> projectOutputs = project.getOutputSymbols();
Set<Symbol> scanOutputs = ImmutableSet.copyOf(tableScan.getOutputSymbols());
if (!scanOutputs.containsAll(projectOutputs)) {
return Optional.empty();
}

if (projectOutputsSize == scanOutputsSize) {
return Optional.of(tableScan);
}
return PruneTableScanColumns.pruneColumns(tableScan, ImmutableSet.copyOf(projectOutputs));
}

@Override
public PlanNode visitSort(SortNode node, Context context) {
Context newContext = new Context();
Expand Down
44 changes: 44 additions & 0 deletions ...node/src/test/java/org/apache/iotdb/db/queryengine/plan/relational/analyzer/SortTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -35,13 +35,16 @@
import org.apache.iotdb.db.queryengine.plan.planner.plan.LogicalQueryPlan;
import org.apache.iotdb.db.queryengine.plan.planner.plan.node.sink.IdentitySinkNode;
import org.apache.iotdb.db.queryengine.plan.relational.metadata.Metadata;
import org.apache.iotdb.db.queryengine.plan.relational.planner.PlanTester;
import org.apache.iotdb.db.queryengine.plan.relational.planner.SymbolAllocator;
import org.apache.iotdb.db.queryengine.plan.relational.planner.TableLogicalPlanner;
import org.apache.iotdb.db.queryengine.plan.relational.planner.distribute.TableDistributedPlanner;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.DeviceTableScanNode;
import org.apache.iotdb.db.queryengine.plan.relational.planner.node.ExchangeNode;
import org.apache.iotdb.db.queryengine.plan.statement.component.Ordering;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import org.junit.BeforeClass;
import org.junit.Test;

Expand All @@ -58,6 +61,12 @@
import static org.apache.iotdb.db.queryengine.plan.relational.analyzer.TestUtils.TEST_MATADATA;
import static org.apache.iotdb.db.queryengine.plan.relational.analyzer.TestUtils.assertTableScan;
import static org.apache.iotdb.db.queryengine.plan.relational.analyzer.TestUtils.getChildrenNode;
import static org.apache.iotdb.db.queryengine.plan.relational.planner.assertions.PlanAssert.assertPlan;
import static org.apache.iotdb.db.queryengine.plan.relational.planner.assertions.PlanMatchPattern.exchange;
import static org.apache.iotdb.db.queryengine.plan.relational.planner.assertions.PlanMatchPattern.mergeSort;
import static org.apache.iotdb.db.queryengine.plan.relational.planner.assertions.PlanMatchPattern.output;
import static org.apache.iotdb.db.queryengine.plan.relational.planner.assertions.PlanMatchPattern.project;
import static org.apache.iotdb.db.queryengine.plan.relational.planner.assertions.PlanMatchPattern.tableScan;
import static org.apache.iotdb.db.queryengine.plan.statement.component.Ordering.ASC;
import static org.apache.iotdb.db.queryengine.plan.statement.component.Ordering.DESC;
import static org.junit.Assert.assertEquals;
Expand Down Expand Up @@ -767,4 +776,39 @@ public void assertTopKNoFilter(
expectedPushDownOffset,
isPushLimitToEachDevice);
}

@Test
public void singleDeviceOrderByAllIdsAndTimeDescTest() {
PlanTester planTester = new PlanTester();
planTester.createPlan(
"SELECT s1, s2, s3 FROM table1 "
+ "WHERE time >= 1000 AND time <= 2000 AND tag1='beijing' AND tag2='A1'"
+ "ORDER BY tag1, tag2, tag3, time DESC");
assertPlan(
planTester.getFragmentPlan(0),
output(
tableScan(
"testdb.table1",
ImmutableList.of("s1", "s2", "s3"),
ImmutableSet.of("time", "s1", "s2", "s3"))));
}

@Test
public void multiDeviceOrderByAllIdsAndTimeDescTest() {
PlanTester planTester = new PlanTester();
planTester.createPlan(
"SELECT s1, s2, s3 FROM table1 "
+ "WHERE time >= 1000 AND time <= 2000 AND tag1='beijing' "
+ "ORDER BY tag1, tag2, tag3, time DESC");
assertPlan(
planTester.getFragmentPlan(0),
output(project(mergeSort(exchange(), exchange(), exchange()))));
// Device in multi-region
assertPlan(
planTester.getFragmentPlan(1),
tableScan(
"testdb.table1",
ImmutableList.of("time", "tag1", "tag2", "tag3", "s1", "s2", "s3"),
ImmutableSet.of("time", "tag1", "tag2", "tag3", "s1", "s2", "s3")));
}
}
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