lower query optimizer overhead

Author: hmottestad

core/queryalgebra/evaluation/src/main/java/org/eclipse/rdf4j/query/algebra/evaluation/optimizer/FilterSelectivityTelemetry.java

@@ -23,7 +23,12 @@ private FilterSelectivityTelemetry() {
 	}
 
 	static void annotate(Filter filter, EvaluationStatistics statistics) {
-		if (statistics == null) {
+		if (filter == null || statistics == null) {
+			return;
+		}
+		double passRatio = filter.getDoubleMetricPlanned(TelemetryMetricNames.PLANNED_FILTER_PASS_RATIO);
+		if (isValidPassRatio(passRatio)) {
+			annotate(filter, statistics, null);
 			return;
 		}
 		annotate(filter, statistics, statistics.estimateFilterPass(filter));
@@ -35,8 +40,12 @@ static void annotate(Filter filter, EvaluationStatistics statistics,
 			return;
 		}
 
-		double passRatio = estimate == null ? -1.0d : estimate.getPassRatio();
-		String source = estimate == null ? null : estimate.getSource().name().toLowerCase();
+		double passRatio = filter.getDoubleMetricPlanned(TelemetryMetricNames.PLANNED_FILTER_PASS_RATIO);
+		String source = filter.getStringMetricPlanned(TelemetryMetricNames.FILTER_SELECTIVITY_SOURCE);
+		if (!isValidPassRatio(passRatio)) {
+			passRatio = estimate == null ? -1.0d : estimate.getPassRatio();
+			source = estimate == null ? null : estimate.getSource().name().toLowerCase();
+		}
 		if (!isValidPassRatio(passRatio)) {
 			double cardinalityPassRatio = estimateCardinalityPassRatio(filter, statistics);
 			if (isValidPassRatio(cardinalityPassRatio)) {

core/queryalgebra/evaluation/src/main/java/org/eclipse/rdf4j/query/algebra/evaluation/optimizer/QueryJoinOptimizer.java

@@ -169,7 +169,19 @@ private static int filterConditionCost(ValueExpr condition) {
 	 */
 	@Override
 	public void optimize(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings) {
-		tupleExpr.visit(new JoinVisitor());
+		QueryOptimizationScopeProvider.QueryOptimizationScope scope = beginQueryOptimizationScope();
+		try {
+			tupleExpr.visit(new JoinVisitor());
+		} finally {
+			scope.close();
+		}
+	}
+
+	private QueryOptimizationScopeProvider.QueryOptimizationScope beginQueryOptimizationScope() {
+		if (statistics instanceof QueryOptimizationScopeProvider) {
+			return ((QueryOptimizationScopeProvider) statistics).beginQueryOptimizationScope();
+		}
+		return QueryOptimizationScopeProvider.NO_OP_SCOPE;
 	}
 
 	/**

core/queryalgebra/evaluation/src/main/java/org/eclipse/rdf4j/query/algebra/evaluation/optimizer/QueryOptimizationScopeProvider.java

@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *******************************************************************************/
+// Some portions generated by Codex
+package org.eclipse.rdf4j.query.algebra.evaluation.optimizer;
+
+/**
+ * Optional hook for statistics implementations that can share short-lived caches during one optimizer pass.
+ */
+public interface QueryOptimizationScopeProvider {
+
+	QueryOptimizationScope NO_OP_SCOPE = () -> {
+	};
+
+	QueryOptimizationScope beginQueryOptimizationScope();
+
+	@FunctionalInterface
+	interface QueryOptimizationScope extends AutoCloseable {
+
+		@Override
+		void close();
+	}
+}

core/queryalgebra/evaluation/src/test/java/org/eclipse/rdf4j/query/algebra/evaluation/impl/QueryJoinOptimizerTest.java

@@ -56,6 +56,7 @@
 import org.eclipse.rdf4j.query.algebra.evaluation.optimizer.JoinFactorCostModel;
 import org.eclipse.rdf4j.query.algebra.evaluation.optimizer.JoinOrderPlanner;
 import org.eclipse.rdf4j.query.algebra.evaluation.optimizer.QueryJoinOptimizer;
+import org.eclipse.rdf4j.query.algebra.evaluation.optimizer.QueryOptimizationScopeProvider;
 import org.eclipse.rdf4j.query.algebra.helpers.AbstractQueryModelVisitor;
 import org.eclipse.rdf4j.query.algebra.helpers.QueryModelTreeToGenericPlanNode;
 import org.eclipse.rdf4j.query.algebra.helpers.TupleExprs;
@@ -75,6 +76,34 @@ public class QueryJoinOptimizerTest extends QueryOptimizerTest {
 
 	private static final ValueFactory VF = SimpleValueFactory.getInstance();
 
+	@Test
+	public void optimizerOpensOneStatisticsOptimizationScope() {
+		ScopedStatistics statistics = new ScopedStatistics();
+		QueryRoot root = new QueryRoot(new Join(
+				statementPattern("s", "o1", ex("pA")),
+				statementPattern("s", "o2", ex("pB"))));
+
+		new QueryJoinOptimizer(statistics, new EmptyTripleSource()).optimize(root, null, null);
+
+		assertEquals(1, statistics.openedScopes);
+		assertEquals(1, statistics.closedScopes);
+		assertEquals(0, statistics.activeScopes);
+		assertTrue(statistics.cardinalityCalls > 0, "Expected optimizer to use statistics inside the opened scope");
+	}
+
+	@Test
+	public void filterTelemetryUsesPlannedPassRatioWithoutCardinalityFallback() {
+		CardinalityCountingStatistics statistics = new CardinalityCountingStatistics();
+		Filter filter = filter(statementPattern("s", "o", ex("pA")), "s", "o");
+		filter.setDoubleMetricPlanned(TelemetryMetricNames.PLANNED_FILTER_PASS_RATIO, 0.25d);
+
+		new QueryJoinOptimizer(statistics, new EmptyTripleSource()).optimize(new QueryRoot(filter), null, null);
+
+		assertEquals(0, statistics.filterCardinalityCalls,
+				"Existing planned filter pass ratio should avoid recursive full filter cardinality estimation");
+		assertEquals(0.25d, filter.getDoubleMetricPlanned(TelemetryMetricNames.PLANNED_FILTER_PASS_RATIO), 0.0d);
+	}
+
 	@Test
 	public void testBindingSetAssignmentOptimization() throws RDF4JException {
 		String query = "prefix ex: <ex:>" + "select ?s ?p ?o ?x where {" + " ex:s1 ex:pred ?v. "
@@ -1350,6 +1379,42 @@ private String predicate(TupleExpr expr) {
 		}
 	}
 
+	private static final class ScopedStatistics extends EvaluationStatistics implements QueryOptimizationScopeProvider {
+		private int openedScopes;
+		private int closedScopes;
+		private int activeScopes;
+		private int cardinalityCalls;
+
+		@Override
+		public QueryOptimizationScope beginQueryOptimizationScope() {
+			openedScopes++;
+			activeScopes++;
+			return () -> {
+				closedScopes++;
+				activeScopes--;
+			};
+		}
+
+		@Override
+		public double getCardinality(TupleExpr expr) {
+			cardinalityCalls++;
+			assertTrue(activeScopes > 0, "Cardinality estimation should run inside the optimization scope");
+			return super.getCardinality(expr);
+		}
+	}
+
+	private static final class CardinalityCountingStatistics extends EvaluationStatistics {
+		private int filterCardinalityCalls;
+
+		@Override
+		public double getCardinality(TupleExpr expr) {
+			if (expr instanceof Filter) {
+				filterCardinalityCalls++;
+			}
+			return super.getCardinality(expr);
+		}
+	}
+
 	private static final class ParsedQueryPairwiseJoinStatistics extends EvaluationStatistics {
 		private final Map<String, Double> joinCosts;