xiedeyantu commented on code in PR #4709: URL: https://github.com/apache/calcite/pull/4709#discussion_r2649188687
########## core/src/main/java/org/apache/calcite/rel/rules/UnnestDecorrelateRule.java: ########## @@ -0,0 +1,151 @@ +/* + * 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.calcite.rel.rules; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelOptUtil; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Correlate; +import org.apache.calcite.rel.core.CorrelationId; +import org.apache.calcite.rel.core.Project; +import org.apache.calcite.rel.core.Uncollect; +import org.apache.calcite.rel.logical.LogicalValues; +import org.apache.calcite.rex.RexCorrelVariable; +import org.apache.calcite.rex.RexFieldAccess; +import org.apache.calcite.rex.RexInputRef; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.tools.RelBuilder; +import org.apache.calcite.util.ImmutableBitSet; + +import org.immutables.value.Value; + +import java.util.List; + +/** Convert representations of a projected Unnest that use LogicalCorrelate into + * simple Unnest representations. + * + * <p>Original plan: + * LogicalProject // only uses rightmost columns of correlate, outerProject + * LogicalCorrelate(correlation=[$cor0], joinType=[inner], requiredColumns=[{...}]) + * LeftSubquery + * LogicalProject (optional; innerProject) + * Uncollect + * LogicalProject(COL=[$cor0.ARRAY]) + * LogicalValues(tuples=[[{ 0 }]]) + * + * <p>is converted to + * + * <p>Resulting plan: + * LogicalProject + * LogicalProject (optional) + * Uncollect + * LogicalProject + * LeftSubquery + */ [email protected] +public class UnnestDecorrelateRule extends RelRule<UnnestDecorrelateRule.Config> + implements TransformationRule { + + protected UnnestDecorrelateRule(UnnestDecorrelateRule.Config config) { + super(config); + } + + @Override public void onMatch(RelOptRuleCall call) { + Project outerProject = call.rel(0); + Correlate cor = call.rel(1); + CorrelationId corId = cor.getCorrelationId(); + + RelNode left = call.rel(2); + int leftCount = left.getRowType().getFieldCount(); + ImmutableBitSet used = RelOptUtil.InputFinder.bits(outerProject.getProjects(), null); + for (int ref : used) { + if (ref < leftCount) { + return; + } + } + + int uncollectIndex = 3; + Project innerProject = null; + if (call.rel(uncollectIndex) instanceof Project) { + innerProject = call.rel(3); + uncollectIndex = 4; + } + + Uncollect uncollect = call.rel(uncollectIndex); + Project project = call.rel(uncollectIndex + 1); + + List<RexNode> projects = project.getProjects(); + if (projects.size() != 1) { + return; + } + + RexNode projected = projects.get(0); + if (projected instanceof RexFieldAccess) { + RexFieldAccess fa = (RexFieldAccess) projected; + RexNode referenceExpr = fa.getReferenceExpr(); + if (referenceExpr instanceof RexCorrelVariable) { + RexCorrelVariable cv = (RexCorrelVariable) referenceExpr; + if (cv.id != corId) { + return; + } + + RelBuilder builder = call.builder(); + builder.push(left); + + RexInputRef field = builder.field(fa.getField().getName()); + builder.project(field); + builder.uncollect(uncollect.getItemAliases(), uncollect.withOrdinality); + if (innerProject != null) { + builder.project(innerProject.getProjects()); + } + List<RexNode> shifted = RexUtil.shift(outerProject.getProjects(), -leftCount); + builder.project(shifted); + RelNode result = builder.build(); Review Comment: A small suggestion. It seems that all the operations related to the builder can be linked together in a point-like manner. ########## core/src/test/java/org/apache/calcite/test/RelOptRulesTest.java: ########## @@ -673,6 +673,46 @@ private HepProgram createHypergraphProgram() { .checkUnchanged(); } + /** Test case for + * <a href="https://issues.apache.org/jira/browse/CALCITE-7196";>[CALCITE-7196] + * Create an optimization pass which can convert some cases of Correlate + Unnest + * to Unnest</a>. */ + @Test void testUnnestDecorrelate() { + final String sql = "WITH t1 AS (SELECT ARRAY[1, 2, 3] as arr)\n" + + "SELECT array_element.id\n" + + "FROM t1, UNNEST(t1.arr) AS array_element(id)"; + sql(sql) + .withRule(CoreRules.UNNEST_PROJECT_DECORRELATE) + .check(); + } + + /** Test case for + * <a href="https://issues.apache.org/jira/browse/CALCITE-7196";>[CALCITE-7196] + * Create an optimization pass which can convert some cases of Correlate + Unnest + * to Unnest</a>. */ + @Test void testUnnestDecorrelate2() { + final String sql = "WITH t1 AS (SELECT ARRAY[1, 2, 3] as arr)\n" + + "SELECT array_element.id, array_element.ord\n" + + "FROM t1, UNNEST(t1.arr) WITH ORDINALITY AS array_element(id, ord)"; + sql(sql) + .withRule(CoreRules.UNNEST_PROJECT_DECORRELATE) + .check(); + } + + /** Test case for + * <a href="https://issues.apache.org/jira/browse/CALCITE-7196";>[CALCITE-7196] + * Create an optimization pass which can convert some cases of Correlate + Unnest + * to Unnest</a>. */ + @Test void testUnnestDecorrelate3() { + final String sql = "WITH t1 AS (SELECT ARRAY[1, 2, 3] as arr)\n" + + "SELECT array_element.id\n" + + "FROM t1, UNNEST(t1.arr) AS array_element(id)"; + sql(sql) + .withPreRule(CoreRules.PROJECT_REMOVE) + .withRule(CoreRules.UNNEST_DECORRELATE) + .check(); + } + Review Comment: I think we can add a test case constructed in a non-Values manner. Like the one below, I tested your code and it looks good. ``` @Test void testUnnestDecorrelate4() { final String sql = "select t2.ename\n" + "from DEPT_NESTED as t1,\n" + "unnest(t1.employees) as t2"; sql(sql) .withPreRule(CoreRules.PROJECT_REMOVE) .withRule(CoreRules.UNNEST_DECORRELATE) .check(); } ``` Xml result: ``` <TestCase name="testUnnestDecorrelate4"> <Resource name="sql"> <![CDATA[select t2.ename from DEPT_NESTED as t1, unnest(t1.employees) as t2]]> </Resource> <Resource name="planBefore"> <![CDATA[ LogicalProject(ENAME=[$5]) LogicalCorrelate(correlation=[$cor0], joinType=[inner], requiredColumns=[{3}]) LogicalTableScan(table=[[CATALOG, SALES, DEPT_NESTED]]) Uncollect LogicalProject(EMPLOYEES=[$cor0.EMPLOYEES]) LogicalValues(tuples=[[{ 0 }]]) ]]> </Resource> <Resource name="planAfter"> <![CDATA[ LogicalProject(ENAME=[$1]) Uncollect LogicalProject(EMPLOYEES=[$3]) LogicalTableScan(table=[[CATALOG, SALES, DEPT_NESTED]]) ]]> </Resource> </TestCase> ``` ########## core/src/main/java/org/apache/calcite/rel/rules/UnnestDecorrelateRule.java: ########## @@ -0,0 +1,151 @@ +/* + * 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.calcite.rel.rules; + +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelOptUtil; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Correlate; +import org.apache.calcite.rel.core.CorrelationId; +import org.apache.calcite.rel.core.Project; +import org.apache.calcite.rel.core.Uncollect; +import org.apache.calcite.rel.logical.LogicalValues; +import org.apache.calcite.rex.RexCorrelVariable; +import org.apache.calcite.rex.RexFieldAccess; +import org.apache.calcite.rex.RexInputRef; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.tools.RelBuilder; +import org.apache.calcite.util.ImmutableBitSet; + +import org.immutables.value.Value; + +import java.util.List; + +/** Convert representations of a projected Unnest that use LogicalCorrelate into + * simple Unnest representations. + * + * <p>Original plan: + * LogicalProject // only uses rightmost columns of correlate, outerProject + * LogicalCorrelate(correlation=[$cor0], joinType=[inner], requiredColumns=[{...}]) + * LeftSubquery + * LogicalProject (optional; innerProject) + * Uncollect + * LogicalProject(COL=[$cor0.ARRAY]) + * LogicalValues(tuples=[[{ 0 }]]) + * + * <p>is converted to + * + * <p>Resulting plan: + * LogicalProject + * LogicalProject (optional) + * Uncollect + * LogicalProject + * LeftSubquery + */ [email protected] +public class UnnestDecorrelateRule extends RelRule<UnnestDecorrelateRule.Config> + implements TransformationRule { + + protected UnnestDecorrelateRule(UnnestDecorrelateRule.Config config) { + super(config); + } + + @Override public void onMatch(RelOptRuleCall call) { + Project outerProject = call.rel(0); + Correlate cor = call.rel(1); + CorrelationId corId = cor.getCorrelationId(); + + RelNode left = call.rel(2); + int leftCount = left.getRowType().getFieldCount(); + ImmutableBitSet used = RelOptUtil.InputFinder.bits(outerProject.getProjects(), null); + for (int ref : used) { Review Comment: ``` int firstUsed = used.nextSetBit(0); if (firstUsed != -1 && firstUsed < leftCount) { return; } ``` Would this be better? -- This is an automated message from the Apache Git Service. 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