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fix(planner): Set the size estimate for a ConstantExpression/Literal #27188

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Merged
tdcmeehan merged 1 commit into from
Feb 24, 2026
Merged

fix(planner): Set the size estimate for a ConstantExpression/Literal #27188

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12 changes: 6 additions & 6 deletions ...o-hive/src/test/java/com/facebook/presto/hive/TestHiveMaterializedViewLogicalPlanner.java
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -2169,6 +2169,11 @@ public void testMaterializedViewOptimizationWithUnsupportedFunctionSubquery()

assertPlan(queryOptimizationWithMaterializedView, baseQuery, anyTree(
node(JoinNode.class,
exchange(
anyTree(
constrainedTableScan(table,
ImmutableMap.of(),
ImmutableMap.of()))),
anyTree(
exchange(
anyTree(
Expand All @@ -2178,12 +2183,7 @@ public void testMaterializedViewOptimizationWithUnsupportedFunctionSubquery()
anyTree(
constrainedTableScan(view2,
ImmutableMap.of(),
ImmutableMap.of("ds_42", "ds", "orderkey_41", "orderkey"))))),
exchange(
anyTree(
constrainedTableScan(table,
ImmutableMap.of(),
ImmutableMap.of()))))));
ImmutableMap.of("ds_42", "ds", "orderkey_41", "orderkey"))))))));
}
finally {
queryRunner.execute("DROP MATERIALIZED VIEW IF EXISTS " + view2);
Expand Down
23 changes: 20 additions & 3 deletions presto-main-base/src/main/java/com/facebook/presto/cost/ScalarStatsCalculator.java
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Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,7 @@
import com.facebook.presto.sql.tree.SymbolReference;
import com.facebook.presto.type.TypeUtils;
import com.google.common.collect.ImmutableMap;
import io.airlift.slice.Slice;
import jakarta.inject.Inject;

import java.util.Map;
Expand Down Expand Up @@ -172,6 +173,9 @@ public VariableStatsEstimate visitConstant(ConstantExpression literal, Void cont
estimate.setLowValue(doubleValue.getAsDouble());
estimate.setHighValue(doubleValue.getAsDouble());
}

setConstantSizeEstimate(literal.getValue(), estimate);

return estimate.build();
}

Expand Down Expand Up @@ -373,6 +377,9 @@ protected VariableStatsEstimate visitLiteral(Literal node, Void context)
estimate.setLowValue(doubleValue.getAsDouble());
estimate.setHighValue(doubleValue.getAsDouble());
}

setConstantSizeEstimate(value, estimate);

return estimate.build();
}

Expand All @@ -393,10 +400,13 @@ protected VariableStatsEstimate visitFunctionCall(FunctionCall node, Void contex
}

// value is a constant
return VariableStatsEstimate.builder()
VariableStatsEstimate.Builder statsEstimate = VariableStatsEstimate.builder()
.setNullsFraction(0)
.setDistinctValuesCount(1)
.build();
.setDistinctValuesCount(1);

setConstantSizeEstimate(value, statsEstimate);

return statsEstimate.build();
}

private Map<NodeRef<Expression>, Type> getExpressionTypes(Session session, Expression expression, TypeProvider types)
Expand Down Expand Up @@ -555,6 +565,13 @@ protected VariableStatsEstimate visitCoalesceExpression(CoalesceExpression node,
}
}

private static void setConstantSizeEstimate(Object value, VariableStatsEstimate.Builder statsEstimate)
{
if (value instanceof Slice) {
statsEstimate.setAverageRowSize(((Slice) value).length());
}
}

private static VariableStatsEstimate estimateCoalesce(PlanNodeStatsEstimate input, VariableStatsEstimate left, VariableStatsEstimate right)
{
// Question to reviewer: do you have a method to check if fraction is empty or saturated?
Expand Down
5 changes: 4 additions & 1 deletion presto-main-base/src/test/java/com/facebook/presto/cost/TestScalarStatsCalculator.java
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Original file line number Diff line number Diff line change
Expand Up @@ -114,10 +114,12 @@ public void testLiteral()
.highValue(75.5)
.nullsFraction(0.0);

assertCalculate(new StringLiteral("blah"))
VariableStatsAssertion blah = assertCalculate(new StringLiteral("blah"));
blah
.distinctValuesCount(1.0)
.lowValueUnknown()
.highValueUnknown()
.averageRowSize(4.0)
.nullsFraction(0.0);

assertCalculate(new NullLiteral())
Expand Down Expand Up @@ -162,6 +164,7 @@ public void testVarbinaryConstant()
.distinctValuesCount(1.0)
.lowValueUnknown()
.highValueUnknown()
.averageRowSize(11.0)
.nullsFraction(0.0);
}

Expand Down
62 changes: 56 additions & 6 deletions .../presto/sql/planner/optimizations/TestReplaceConstantVariableReferencesWithConstants.java
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Original file line number Diff line number Diff line change
Expand Up @@ -14,16 +14,27 @@
package com.facebook.presto.sql.planner.optimizations;

import com.facebook.presto.Session;
import com.facebook.presto.cost.StatsProvider;
import com.facebook.presto.cost.VariableStatsEstimate;
import com.facebook.presto.metadata.Metadata;
import com.facebook.presto.spi.plan.JoinType;
import com.facebook.presto.spi.plan.OutputNode;
import com.facebook.presto.spi.plan.PlanNode;
import com.facebook.presto.spi.relation.VariableReferenceExpression;
import com.facebook.presto.sql.planner.assertions.BasePlanTest;
import com.facebook.presto.sql.planner.assertions.MatchResult;
import com.facebook.presto.sql.planner.assertions.Matcher;
import com.facebook.presto.sql.planner.assertions.PlanMatchPattern;
import com.facebook.presto.sql.planner.assertions.SymbolAliases;
import com.facebook.presto.sql.planner.iterative.rule.test.RuleTester;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableListMultimap;
import com.google.common.collect.ImmutableMap;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import java.util.Map;

import static com.facebook.presto.SystemSessionProperties.REWRITE_EXPRESSION_WITH_CONSTANT_EXPRESSION;
import static com.facebook.presto.common.type.IntegerType.INTEGER;
import static com.facebook.presto.metadata.FunctionAndTypeManager.createTestFunctionAndTypeManager;
Expand All @@ -48,10 +59,21 @@
import static com.facebook.presto.sql.planner.iterative.rule.test.PlanBuilder.assignment;
import static com.facebook.presto.sql.tree.SortItem.NullOrdering.LAST;
import static com.facebook.presto.sql.tree.SortItem.Ordering.ASCENDING;
import static org.testng.Assert.assertEquals;

public class TestReplaceConstantVariableReferencesWithConstants
extends BasePlanTest
{
@DataProvider
public static Object[][] filterProviders()
{
return new Object[][] {
{"3-MEDIUM"},
{"2-LOOOOOOONG"},
{"123456789012345"} // orderpriority is a VARCHAR(15), this is the max length after which a Constant replacement is not applied
};
}

private Session enableOptimization()
{
return Session.builder(this.getQueryRunner().getDefaultSession())
Expand Down Expand Up @@ -179,18 +201,46 @@ public void testSemiJoin()
tableScan("lineitem", ImmutableMap.of("orderkey_1", "orderkey"))))))))));
}

@Test
public void testSimpleFilter()
@Test(dataProvider = "filterProviders")
public void testSimpleFilter(String filter)
{
assertPlan("select orderkey, orderpriority from orders where orderpriority='3-MEDIUM'",
assertPlan("select orderkey, orderpriority from orders where orderpriority='" + filter + "'",
enableOptimization(),
output(
ImmutableList.of("orderkey", "expr_6"),
project(
ImmutableMap.of("expr_6", expression("'3-MEDIUM'")),
ImmutableMap.of("expr_6", expression("'" + filter + "'")),
filter(
"orderpriority = '3-MEDIUM'",
tableScan("orders", ImmutableMap.of("orderkey", "orderkey", "orderpriority", "orderpriority"))))));
"orderpriority = '" + filter + "'",
tableScan("orders", ImmutableMap.of("orderkey", "orderkey", "orderpriority", "orderpriority")))))
.with(new Matcher()
{
@Override
public boolean shapeMatches(PlanNode node)
{
return node instanceof OutputNode;
}

@Override
public MatchResult detailMatches(PlanNode node, StatsProvider stats, Session session, Metadata metadata, SymbolAliases symbolAliases)
{
// Assert additionally ont size estimate of the replaced VARCHAR ConstantExpression
VariableStatsEstimate expectedStats = VariableStatsEstimate.builder()
.setAverageRowSize(filter.length())
.setDistinctValuesCount(1)
.setNullsFraction(0.0)
.build();

VariableStatsEstimate actualStats = stats.getStats(node).getVariableStatistics().entrySet().stream()
.filter(es -> es.getKey().getName().equals("orderpriority"))
.map(Map.Entry::getValue)
.findFirst()
.orElseThrow(() -> new AssertionError("Variable 'orderpriority' not found in statistics"));

assertEquals(actualStats, expectedStats);
return MatchResult.match();
}
}));
}

@Test
Expand Down
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