mihaibudiu commented on code in PR #4267:
URL: https://github.com/apache/calcite/pull/4267#discussion_r2045206359
##########
core/src/main/java/org/apache/calcite/rel/rules/CoreRules.java:
##########
@@ -850,4 +850,16 @@ private CoreRules() {}
@Experimental
public static final DphypJoinReorderRule HYPER_GRAPH_OPTIMIZE =
DphypJoinReorderRule.Config.DEFAULT.toRule();
+
+ /** Rule that expand disjuction in condition of a {@link Filter}.
Review Comment:
this "disjunction" is still misspelled
it should also be "expands disjunction in the condition of a filter"
same problems in the comment below
##########
core/src/main/java/org/apache/calcite/rel/rules/ExpandDisjunctionForTableRule.java:
##########
@@ -0,0 +1,429 @@
+/*
+ * 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.Filter;
+import org.apache.calcite.rel.core.Join;
+import org.apache.calcite.rel.metadata.RelMetadataQuery;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexTableInputRef;
+import org.apache.calcite.rex.RexUtil;
+import org.apache.calcite.tools.RelBuilder;
+import org.apache.calcite.util.ControlFlowException;
+import org.apache.calcite.util.ImmutableBitSet;
+
+import com.google.common.collect.Lists;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.immutables.value.Value;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Rule to expand disjunction for single table in condition of a {@link
Filter} or {@link Join},
+ * It makes sense to make this optimization part of the predicate pushdown.
For example:
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * }</pre></blockquote>
+ *
+ * <p>we can expand to obtain the condition
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * and (t1.id > 20 or t1.weight < 200)
+ * and (t2.height < 50 or t2.sales > 100)
+ * }</pre></blockquote>
+ *
+ * <p>new generated predicates are redundant, but they could be pushed down to
+ * scan operator of t1/t2 and reduce the cardinality.
+ *
+ * <p>Note: This rule should only be applied once and it should be used before
+ * {@link CoreRules#FILTER_INTO_JOIN} and {@link
CoreRules#JOIN_CONDITION_PUSH}.
+ * In order to avoid it interacting with other expression-related rules and
causing
+ * an infinite loop, it is recommended to use it alone in HepPlanner first,
+ * and then do predicate pushdown.
+ *
+ * @see CoreRules#EXPAND_FILTER_DISJUNCTION_GLOBAL
+ * @see CoreRules#EXPAND_JOIN_DISJUNCTION_GLOBAL
+ */
[email protected]
+public class ExpandDisjunctionForTableRule
+ extends RelRule<ExpandDisjunctionForTableRule.Config>
+ implements TransformationRule {
+
+ /**
+ * Creates a ExpandDisjunctionForTableRule.
+ */
+ protected ExpandDisjunctionForTableRule(Config config) {
+ super(config);
+ }
+
+ @Override public void onMatch(RelOptRuleCall call) {
+ config.matchHandler().accept(this, call);
+ }
+
+ /**
+ * Expand predicates for condition of a {@link Filter} or {@link Join}.
+ *
+ * @param condition Condition to be expanded in Filter or Join
+ * @param relNode The Filter or Join node
+ * @param fieldList The field list of the Filter or Join inputs.
+ * @param relBuilder Builder
+ * @param mq RelMetadataQuery, which is used to get the expression
lineage
+ *
+ * @return The redundant predicate expanded from the condition parameter. It
is formed by
+ * concatenating the predicates that can be pushed down to single table with
AND.
+ */
+ private RexNode apply(
+ RexNode condition,
+ RelNode relNode,
+ List<RelDataTypeField> fieldList,
+ RelBuilder relBuilder,
+ RelMetadataQuery mq) {
+ final Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef = new
HashMap<>();
+
+ ImmutableBitSet columnBits = RelOptUtil.InputFinder.bits(condition);
+ if (columnBits.isEmpty()) {
+ return condition;
+ }
+
+ // Trace which table does the column referenced in the condition come from
+ for (int columnBit : columnBits.asList()) {
+ Set<RexNode> exprLineage =
+ mq.getExpressionLineage(
+ relNode,
+ RexInputRef.of(columnBit, fieldList));
+ // If mq.getExpressionLineage cannot get result, skip it
+ if (exprLineage == null) {
+ continue;
+ }
+ Set<RexTableInputRef.RelTableRef> relTableRefs =
+ RexUtil.gatherTableReferences(Lists.newArrayList(exprLineage));
+ // If the column comes from multiple tables, skip it
+ if (relTableRefs.isEmpty() || relTableRefs.size() > 1) {
+ continue;
+ }
+ inputRefToTableRef.put(columnBit, relTableRefs.iterator().next());
+ }
+
+ ExpandDisjunctionForTableHelper expandHelper =
+ new ExpandDisjunctionForTableHelper(inputRefToTableRef, relBuilder,
config.bloat());
+ Map<RexTableInputRef.RelTableRef, RexNode> expandResult =
expandHelper.expand(condition);
+
+ RexNode newCondition = condition;
+ for (RexNode expandCondition : expandResult.values()) {
+ newCondition = relBuilder.and(newCondition, expandCondition);
+ }
+ return newCondition;
+ }
+
+ private static void matchFilter(ExpandDisjunctionForTableRule rule,
RelOptRuleCall call) {
+ Filter filter = call.rel(0);
+ RelMetadataQuery mq = call.getMetadataQuery();
+ RelBuilder relBuilder = call.builder();
+
+ RexNode newCondition =
+ rule.apply(
+ filter.getCondition(),
+ filter,
+ filter.getRowType().getFieldList(),
+ relBuilder,
+ mq);
+ if (newCondition.equals(filter.getCondition())) {
+ return;
+ }
+ Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(),
newCondition);
+ call.transformTo(newFilter);
+ }
+
+ private static void matchJoin(ExpandDisjunctionForTableRule rule,
RelOptRuleCall call) {
+ Join join = call.rel(0);
+ RelMetadataQuery mq = call.getMetadataQuery();
+ RelBuilder relBuilder = call.builder();
+
+ List<RelDataTypeField> fieldList =
+ Lists.newArrayList(join.getLeft().getRowType().getFieldList());
+ fieldList.addAll(join.getRight().getRowType().getFieldList());
+ RexNode newCondition =
+ rule.apply(
+ join.getCondition(),
+ join,
+ fieldList,
+ relBuilder,
+ mq);
+ if (newCondition.equals(join.getCondition())) {
+ return;
+ }
+ Join newJoin =
+ join.copy(
+ join.getTraitSet(),
+ newCondition,
+ join.getLeft(),
+ join.getRight(),
+ join.getJoinType(),
+ join.isSemiJoinDone());
+ call.transformTo(newJoin);
+ }
+
+ /**
+ * Helper class to expand predicates.
+ */
+ private static class ExpandDisjunctionForTableHelper {
+ private final Map<Integer, RexTableInputRef.RelTableRef>
inputRefToTableRef;
+
+ private final RelBuilder relBuilder;
+
+ private final int maxNodeCount;
+
+ // Used to record the number of redundant expressions expanded.
+ private int currentCount;
+
+ private ExpandDisjunctionForTableHelper(
+ Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef,
+ RelBuilder relBuilder,
+ int maxNodeCount) {
+ this.inputRefToTableRef = inputRefToTableRef;
+ this.relBuilder = relBuilder;
+ this.maxNodeCount = maxNodeCount;
+ }
+
+ private Map<RexTableInputRef.RelTableRef, RexNode> expand(RexNode
condition) {
+ try {
+ this.currentCount = 0;
+ return expandDeep(condition);
+ } catch (OverLimitException e) {
+ return new HashMap<>();
+ }
+ }
+
+ /**
+ * Expand predicates recursively that can be pushed down to single table.
+ *
+ * @param condition Predicate to be expanded
+ * @return A map from a table to a (combined) predicate that can be
pushed down
+ * and only depends on columns of the table
+ */
+ private Map<RexTableInputRef.RelTableRef, RexNode> expandDeep(RexNode
condition) {
+ Map<RexTableInputRef.RelTableRef, RexNode> additionalConditions = new
HashMap<>();
+
+ ImmutableBitSet inputRefs = RelOptUtil.InputFinder.bits(condition);
+ if (inputRefs.isEmpty()) {
+ return additionalConditions;
+ }
+
+ RexTableInputRef.RelTableRef tableRef =
inputRefsBelongToOneTable(inputRefs);
+ if (tableRef != null) {
+ // The condition already belongs to one table, return it directly
+ checkExpandCount(condition.nodeCount());
+ additionalConditions.put(tableRef, condition);
+ return additionalConditions;
+ }
+
+ // Recursively expand the expression according to whether it is a
conjunction
+ // or a disjunction. If it is neither a disjunction nor a conjunction,
it cannot
+ // be expanded further and an empty Map is returned.
+ switch (condition.getKind()) {
+ case AND:
+ List<RexNode> andOperands = RexUtil.flattenAnd(((RexCall)
condition).getOperands());
+ for (RexNode andOperand : andOperands) {
+ Map<RexTableInputRef.RelTableRef, RexNode> operandResult =
expandDeep(andOperand);
+ combinePredicatesUsingAnd(additionalConditions, operandResult);
+ }
+ break;
+ case OR:
+ List<RexNode> orOperands = RexUtil.flattenOr(((RexCall)
condition).getOperands());
+ additionalConditions.putAll(expandDeep(orOperands.get(0)));
+ for (int i = 1; i < orOperands.size(); i++) {
+ Map<RexTableInputRef.RelTableRef, RexNode> operandResult =
+ expandDeep(orOperands.get(i));
+ combinePredicatesUsingOr(additionalConditions, operandResult);
+
+ if (additionalConditions.isEmpty()) {
+ break;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+
+ return additionalConditions;
+ }
+
+ private RexTableInputRef.@Nullable RelTableRef inputRefsBelongToOneTable(
+ ImmutableBitSet inputRefs) {
+ RexTableInputRef.RelTableRef tableRef =
inputRefToTableRef.get(inputRefs.nth(0));
+ if (tableRef == null) {
+ return null;
+ }
+ for (int inputBit : inputRefs.asList()) {
+ RexTableInputRef.RelTableRef inputBitTableRef =
inputRefToTableRef.get(inputBit);
+ if (!tableRef.equals(inputBitTableRef)) {
+ return null;
+ }
+ }
+ return tableRef;
+ }
+
+ /**
+ * Combine predicates that depend on the same table using conjunctions, and
Review Comment:
Combine predicates that depend on the same table using conjunctions.
The result is returned by modifying baseMap.
##########
core/src/main/java/org/apache/calcite/rel/rules/ExpandDisjunctionForTableRule.java:
##########
@@ -0,0 +1,429 @@
+/*
+ * 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.Filter;
+import org.apache.calcite.rel.core.Join;
+import org.apache.calcite.rel.metadata.RelMetadataQuery;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexTableInputRef;
+import org.apache.calcite.rex.RexUtil;
+import org.apache.calcite.tools.RelBuilder;
+import org.apache.calcite.util.ControlFlowException;
+import org.apache.calcite.util.ImmutableBitSet;
+
+import com.google.common.collect.Lists;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.immutables.value.Value;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Rule to expand disjunction for single table in condition of a {@link
Filter} or {@link Join},
+ * It makes sense to make this optimization part of the predicate pushdown.
For example:
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * }</pre></blockquote>
+ *
+ * <p>we can expand to obtain the condition
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * and (t1.id > 20 or t1.weight < 200)
+ * and (t2.height < 50 or t2.sales > 100)
+ * }</pre></blockquote>
+ *
+ * <p>new generated predicates are redundant, but they could be pushed down to
+ * scan operator of t1/t2 and reduce the cardinality.
+ *
+ * <p>Note: This rule should only be applied once and it should be used before
+ * {@link CoreRules#FILTER_INTO_JOIN} and {@link
CoreRules#JOIN_CONDITION_PUSH}.
+ * In order to avoid it interacting with other expression-related rules and
causing
+ * an infinite loop, it is recommended to use it alone in HepPlanner first,
+ * and then do predicate pushdown.
+ *
+ * @see CoreRules#EXPAND_FILTER_DISJUNCTION_GLOBAL
+ * @see CoreRules#EXPAND_JOIN_DISJUNCTION_GLOBAL
+ */
[email protected]
+public class ExpandDisjunctionForTableRule
+ extends RelRule<ExpandDisjunctionForTableRule.Config>
+ implements TransformationRule {
+
+ /**
+ * Creates a ExpandDisjunctionForTableRule.
+ */
+ protected ExpandDisjunctionForTableRule(Config config) {
+ super(config);
+ }
+
+ @Override public void onMatch(RelOptRuleCall call) {
+ config.matchHandler().accept(this, call);
+ }
+
+ /**
+ * Expand predicates for condition of a {@link Filter} or {@link Join}.
+ *
+ * @param condition Condition to be expanded in Filter or Join
+ * @param relNode The Filter or Join node
+ * @param fieldList The field list of the Filter or Join inputs.
+ * @param relBuilder Builder
+ * @param mq RelMetadataQuery, which is used to get the expression
lineage
+ *
+ * @return The redundant predicate expanded from the condition parameter. It
is formed by
+ * concatenating the predicates that can be pushed down to single table with
AND.
+ */
+ private RexNode apply(
+ RexNode condition,
+ RelNode relNode,
+ List<RelDataTypeField> fieldList,
+ RelBuilder relBuilder,
+ RelMetadataQuery mq) {
+ final Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef = new
HashMap<>();
+
+ ImmutableBitSet columnBits = RelOptUtil.InputFinder.bits(condition);
+ if (columnBits.isEmpty()) {
+ return condition;
+ }
+
+ // Trace which table does the column referenced in the condition come from
+ for (int columnBit : columnBits.asList()) {
+ Set<RexNode> exprLineage =
+ mq.getExpressionLineage(
+ relNode,
+ RexInputRef.of(columnBit, fieldList));
+ // If mq.getExpressionLineage cannot get result, skip it
+ if (exprLineage == null) {
+ continue;
+ }
+ Set<RexTableInputRef.RelTableRef> relTableRefs =
+ RexUtil.gatherTableReferences(Lists.newArrayList(exprLineage));
+ // If the column comes from multiple tables, skip it
+ if (relTableRefs.isEmpty() || relTableRefs.size() > 1) {
+ continue;
+ }
+ inputRefToTableRef.put(columnBit, relTableRefs.iterator().next());
+ }
+
+ ExpandDisjunctionForTableHelper expandHelper =
+ new ExpandDisjunctionForTableHelper(inputRefToTableRef, relBuilder,
config.bloat());
+ Map<RexTableInputRef.RelTableRef, RexNode> expandResult =
expandHelper.expand(condition);
+
+ RexNode newCondition = condition;
+ for (RexNode expandCondition : expandResult.values()) {
+ newCondition = relBuilder.and(newCondition, expandCondition);
+ }
+ return newCondition;
+ }
+
+ private static void matchFilter(ExpandDisjunctionForTableRule rule,
RelOptRuleCall call) {
+ Filter filter = call.rel(0);
+ RelMetadataQuery mq = call.getMetadataQuery();
+ RelBuilder relBuilder = call.builder();
+
+ RexNode newCondition =
+ rule.apply(
+ filter.getCondition(),
+ filter,
+ filter.getRowType().getFieldList(),
+ relBuilder,
+ mq);
+ if (newCondition.equals(filter.getCondition())) {
+ return;
+ }
+ Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(),
newCondition);
+ call.transformTo(newFilter);
+ }
+
+ private static void matchJoin(ExpandDisjunctionForTableRule rule,
RelOptRuleCall call) {
+ Join join = call.rel(0);
+ RelMetadataQuery mq = call.getMetadataQuery();
+ RelBuilder relBuilder = call.builder();
+
+ List<RelDataTypeField> fieldList =
+ Lists.newArrayList(join.getLeft().getRowType().getFieldList());
+ fieldList.addAll(join.getRight().getRowType().getFieldList());
+ RexNode newCondition =
+ rule.apply(
+ join.getCondition(),
+ join,
+ fieldList,
+ relBuilder,
+ mq);
+ if (newCondition.equals(join.getCondition())) {
+ return;
+ }
+ Join newJoin =
+ join.copy(
+ join.getTraitSet(),
+ newCondition,
+ join.getLeft(),
+ join.getRight(),
+ join.getJoinType(),
+ join.isSemiJoinDone());
+ call.transformTo(newJoin);
+ }
+
+ /**
+ * Helper class to expand predicates.
+ */
+ private static class ExpandDisjunctionForTableHelper {
+ private final Map<Integer, RexTableInputRef.RelTableRef>
inputRefToTableRef;
+
+ private final RelBuilder relBuilder;
+
+ private final int maxNodeCount;
+
+ // Used to record the number of redundant expressions expanded.
+ private int currentCount;
+
+ private ExpandDisjunctionForTableHelper(
+ Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef,
+ RelBuilder relBuilder,
+ int maxNodeCount) {
+ this.inputRefToTableRef = inputRefToTableRef;
+ this.relBuilder = relBuilder;
+ this.maxNodeCount = maxNodeCount;
+ }
+
+ private Map<RexTableInputRef.RelTableRef, RexNode> expand(RexNode
condition) {
+ try {
+ this.currentCount = 0;
+ return expandDeep(condition);
+ } catch (OverLimitException e) {
+ return new HashMap<>();
+ }
+ }
+
+ /**
+ * Expand predicates recursively that can be pushed down to single table.
+ *
+ * @param condition Predicate to be expanded
+ * @return A map from a table to a (combined) predicate that can be
pushed down
+ * and only depends on columns of the table
+ */
+ private Map<RexTableInputRef.RelTableRef, RexNode> expandDeep(RexNode
condition) {
+ Map<RexTableInputRef.RelTableRef, RexNode> additionalConditions = new
HashMap<>();
+
+ ImmutableBitSet inputRefs = RelOptUtil.InputFinder.bits(condition);
+ if (inputRefs.isEmpty()) {
+ return additionalConditions;
+ }
+
+ RexTableInputRef.RelTableRef tableRef =
inputRefsBelongToOneTable(inputRefs);
+ if (tableRef != null) {
+ // The condition already belongs to one table, return it directly
+ checkExpandCount(condition.nodeCount());
+ additionalConditions.put(tableRef, condition);
+ return additionalConditions;
+ }
+
+ // Recursively expand the expression according to whether it is a
conjunction
+ // or a disjunction. If it is neither a disjunction nor a conjunction,
it cannot
+ // be expanded further and an empty Map is returned.
+ switch (condition.getKind()) {
+ case AND:
+ List<RexNode> andOperands = RexUtil.flattenAnd(((RexCall)
condition).getOperands());
+ for (RexNode andOperand : andOperands) {
+ Map<RexTableInputRef.RelTableRef, RexNode> operandResult =
expandDeep(andOperand);
+ combinePredicatesUsingAnd(additionalConditions, operandResult);
+ }
+ break;
+ case OR:
+ List<RexNode> orOperands = RexUtil.flattenOr(((RexCall)
condition).getOperands());
+ additionalConditions.putAll(expandDeep(orOperands.get(0)));
+ for (int i = 1; i < orOperands.size(); i++) {
+ Map<RexTableInputRef.RelTableRef, RexNode> operandResult =
+ expandDeep(orOperands.get(i));
+ combinePredicatesUsingOr(additionalConditions, operandResult);
+
+ if (additionalConditions.isEmpty()) {
+ break;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+
+ return additionalConditions;
+ }
+
+ private RexTableInputRef.@Nullable RelTableRef inputRefsBelongToOneTable(
+ ImmutableBitSet inputRefs) {
+ RexTableInputRef.RelTableRef tableRef =
inputRefToTableRef.get(inputRefs.nth(0));
+ if (tableRef == null) {
+ return null;
+ }
+ for (int inputBit : inputRefs.asList()) {
+ RexTableInputRef.RelTableRef inputBitTableRef =
inputRefToTableRef.get(inputBit);
+ if (!tableRef.equals(inputBitTableRef)) {
+ return null;
+ }
+ }
+ return tableRef;
+ }
+
+ /**
+ * Combine predicates that depend on the same table using conjunctions, and
+ * specify that the result is returned by modifying baseMap. For example:
+ *
+ * <p>baseMap: {t1: p1, t2: p2}
+ *
+ * <p>forMergeMap: {t1: p11, t3: p3}
+ *
+ * <p>result: {t1: p1 AND p11, t2: p2, t3: p3}
+ *
+ * @param baseMap Additional predicates that current conjunction has
already saved
+ * @param forMergeMap Additional predicates that current operand has
expanded
+ */
+ private void combinePredicatesUsingAnd(
+ Map<RexTableInputRef.RelTableRef, RexNode> baseMap,
+ Map<RexTableInputRef.RelTableRef, RexNode> forMergeMap) {
+ for (Map.Entry<RexTableInputRef.RelTableRef, RexNode> entry :
forMergeMap.entrySet()) {
+ RexNode mergedRex =
+ relBuilder.and(
+ entry.getValue(),
+ baseMap.getOrDefault(entry.getKey(),
relBuilder.literal(true)));
+ int oriCount = entry.getValue().nodeCount()
+ + (baseMap.containsKey(entry.getKey())
+ ? baseMap.get(entry.getKey()).nodeCount()
+ : 0);
+ checkExpandCount(mergedRex.nodeCount() - oriCount);
+ baseMap.put(entry.getKey(), mergedRex);
+ }
+ }
+
+ /**
+ * Combine predicates that depend on the same table using disjunctions, and
+ * specify that the result is returned by modifying baseMap. For example:
+ *
+ * <p>baseMap: {t1: p1, t2: p2}
+ *
+ * <p>forMergeMap: {t1: p11, t3: p3}
+ *
+ * <p>result: {t1: p1 OR p11}
+ *
+ * @param baseMap Additional predicates that current disjunction has
already saved
+ * @param forMergeMap Additional predicates that current operand has
expanded
+ */
+ private void combinePredicatesUsingOr(
+ Map<RexTableInputRef.RelTableRef, RexNode> baseMap,
+ Map<RexTableInputRef.RelTableRef, RexNode> forMergeMap) {
+ if (baseMap.isEmpty()) {
+ return;
+ }
+
+ Iterator<Map.Entry<RexTableInputRef.RelTableRef, RexNode>> iterator =
+ baseMap.entrySet().iterator();
+ while (iterator.hasNext()) {
+ int forMergeNodeCount = 0;
+
+ Map.Entry<RexTableInputRef.RelTableRef, RexNode> entry =
iterator.next();
+ if (!forMergeMap.containsKey(entry.getKey())) {
+ checkExpandCount(-entry.getValue().nodeCount());
+ iterator.remove();
+ continue;
+ } else {
+ forMergeNodeCount = forMergeMap.get(entry.getKey()).nodeCount();
+ }
+ RexNode mergedRex =
+ relBuilder.or(
+ entry.getValue(),
+ forMergeMap.get(entry.getKey()));
+ int oriCount = entry.getValue().nodeCount() + forMergeNodeCount;
+ checkExpandCount(mergedRex.nodeCount() - oriCount);
+ baseMap.put(entry.getKey(), mergedRex);
+ }
+ }
+
+ /**
+ * Check whether the number of redundant expressions generated in the
expansion
+ * exceeds the limit.
+ */
+ private void checkExpandCount(int changeCount) {
+ currentCount += changeCount;
+ if (maxNodeCount > 0 && currentCount > maxNodeCount) {
+ throw OverLimitException.INSTANCE;
+ }
+ }
+
+ /** Exception to catch when we pass the limit. */
+ private static class OverLimitException extends ControlFlowException {
+ protected static final OverLimitException INSTANCE = new
OverLimitException();
+
+ private OverLimitException() {}
+ }
+ }
+
+ /** Rule configuration. */
+ @Value.Immutable(singleton = false)
+ public interface Config extends RelRule.Config {
+ Config FILTER = ImmutableExpandDisjunctionForTableRule.Config.builder()
+ .withMatchHandler(ExpandDisjunctionForTableRule::matchFilter)
+ .build()
+ .withOperandSupplier(b -> b.operand(Filter.class).anyInputs());
+
+ Config JOIN = ImmutableExpandDisjunctionForTableRule.Config.builder()
+ .withMatchHandler(ExpandDisjunctionForTableRule::matchJoin)
+ .build()
+ .withOperandSupplier(b -> b.operand(Join.class).anyInputs());
+
+ @Override default ExpandDisjunctionForTableRule toRule() {
+ return new ExpandDisjunctionForTableRule(this);
+ }
+
+ /**
+ * Limit how much complexity can increase during expanding.
Review Comment:
Limit to the size growth of the condition allowed during expansion.
##########
core/src/main/java/org/apache/calcite/rel/rules/ExpandDisjunctionForTableRule.java:
##########
@@ -0,0 +1,429 @@
+/*
+ * 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.Filter;
+import org.apache.calcite.rel.core.Join;
+import org.apache.calcite.rel.metadata.RelMetadataQuery;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexTableInputRef;
+import org.apache.calcite.rex.RexUtil;
+import org.apache.calcite.tools.RelBuilder;
+import org.apache.calcite.util.ControlFlowException;
+import org.apache.calcite.util.ImmutableBitSet;
+
+import com.google.common.collect.Lists;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.immutables.value.Value;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Rule to expand disjunction for single table in condition of a {@link
Filter} or {@link Join},
+ * It makes sense to make this optimization part of the predicate pushdown.
For example:
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * }</pre></blockquote>
+ *
+ * <p>we can expand to obtain the condition
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * and (t1.id > 20 or t1.weight < 200)
+ * and (t2.height < 50 or t2.sales > 100)
+ * }</pre></blockquote>
+ *
+ * <p>new generated predicates are redundant, but they could be pushed down to
+ * scan operator of t1/t2 and reduce the cardinality.
+ *
+ * <p>Note: This rule should only be applied once and it should be used before
+ * {@link CoreRules#FILTER_INTO_JOIN} and {@link
CoreRules#JOIN_CONDITION_PUSH}.
+ * In order to avoid it interacting with other expression-related rules and
causing
+ * an infinite loop, it is recommended to use it alone in HepPlanner first,
+ * and then do predicate pushdown.
+ *
+ * @see CoreRules#EXPAND_FILTER_DISJUNCTION_GLOBAL
+ * @see CoreRules#EXPAND_JOIN_DISJUNCTION_GLOBAL
+ */
[email protected]
+public class ExpandDisjunctionForTableRule
+ extends RelRule<ExpandDisjunctionForTableRule.Config>
+ implements TransformationRule {
+
+ /**
+ * Creates a ExpandDisjunctionForTableRule.
+ */
+ protected ExpandDisjunctionForTableRule(Config config) {
+ super(config);
+ }
+
+ @Override public void onMatch(RelOptRuleCall call) {
+ config.matchHandler().accept(this, call);
+ }
+
+ /**
+ * Expand predicates for condition of a {@link Filter} or {@link Join}.
+ *
+ * @param condition Condition to be expanded in Filter or Join
+ * @param relNode The Filter or Join node
+ * @param fieldList The field list of the Filter or Join inputs.
+ * @param relBuilder Builder
+ * @param mq RelMetadataQuery, which is used to get the expression
lineage
+ *
+ * @return The redundant predicate expanded from the condition parameter. It
is formed by
+ * concatenating the predicates that can be pushed down to single table with
AND.
+ */
+ private RexNode apply(
+ RexNode condition,
+ RelNode relNode,
+ List<RelDataTypeField> fieldList,
+ RelBuilder relBuilder,
+ RelMetadataQuery mq) {
+ final Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef = new
HashMap<>();
+
+ ImmutableBitSet columnBits = RelOptUtil.InputFinder.bits(condition);
+ if (columnBits.isEmpty()) {
+ return condition;
+ }
+
+ // Trace which table does the column referenced in the condition come from
+ for (int columnBit : columnBits.asList()) {
+ Set<RexNode> exprLineage =
+ mq.getExpressionLineage(
+ relNode,
+ RexInputRef.of(columnBit, fieldList));
+ // If mq.getExpressionLineage cannot get result, skip it
+ if (exprLineage == null) {
+ continue;
+ }
+ Set<RexTableInputRef.RelTableRef> relTableRefs =
+ RexUtil.gatherTableReferences(Lists.newArrayList(exprLineage));
+ // If the column comes from multiple tables, skip it
Review Comment:
What does it mean for a column to "come" from multiple tables?
You mean, it is computed by an expression that depends on multiple tables?
##########
core/src/main/java/org/apache/calcite/rel/rules/ExpandDisjunctionForTableRule.java:
##########
@@ -0,0 +1,429 @@
+/*
+ * 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.Filter;
+import org.apache.calcite.rel.core.Join;
+import org.apache.calcite.rel.metadata.RelMetadataQuery;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexTableInputRef;
+import org.apache.calcite.rex.RexUtil;
+import org.apache.calcite.tools.RelBuilder;
+import org.apache.calcite.util.ControlFlowException;
+import org.apache.calcite.util.ImmutableBitSet;
+
+import com.google.common.collect.Lists;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.immutables.value.Value;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Rule to expand disjunction for single table in condition of a {@link
Filter} or {@link Join},
+ * It makes sense to make this optimization part of the predicate pushdown.
For example:
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * }</pre></blockquote>
+ *
+ * <p>we can expand to obtain the condition
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * and (t1.id > 20 or t1.weight < 200)
+ * and (t2.height < 50 or t2.sales > 100)
+ * }</pre></blockquote>
+ *
+ * <p>new generated predicates are redundant, but they could be pushed down to
+ * scan operator of t1/t2 and reduce the cardinality.
+ *
+ * <p>Note: This rule should only be applied once and it should be used before
+ * {@link CoreRules#FILTER_INTO_JOIN} and {@link
CoreRules#JOIN_CONDITION_PUSH}.
+ * In order to avoid it interacting with other expression-related rules and
causing
+ * an infinite loop, it is recommended to use it alone in HepPlanner first,
+ * and then do predicate pushdown.
+ *
+ * @see CoreRules#EXPAND_FILTER_DISJUNCTION_GLOBAL
+ * @see CoreRules#EXPAND_JOIN_DISJUNCTION_GLOBAL
+ */
[email protected]
+public class ExpandDisjunctionForTableRule
+ extends RelRule<ExpandDisjunctionForTableRule.Config>
+ implements TransformationRule {
+
+ /**
+ * Creates a ExpandDisjunctionForTableRule.
+ */
+ protected ExpandDisjunctionForTableRule(Config config) {
+ super(config);
+ }
+
+ @Override public void onMatch(RelOptRuleCall call) {
+ config.matchHandler().accept(this, call);
+ }
+
+ /**
+ * Expand predicates for condition of a {@link Filter} or {@link Join}.
+ *
+ * @param condition Condition to be expanded in Filter or Join
+ * @param relNode The Filter or Join node
+ * @param fieldList The field list of the Filter or Join inputs.
+ * @param relBuilder Builder
+ * @param mq RelMetadataQuery, which is used to get the expression
lineage
+ *
+ * @return The redundant predicate expanded from the condition parameter. It
is formed by
+ * concatenating the predicates that can be pushed down to single table with
AND.
+ */
+ private RexNode apply(
+ RexNode condition,
+ RelNode relNode,
+ List<RelDataTypeField> fieldList,
+ RelBuilder relBuilder,
+ RelMetadataQuery mq) {
+ final Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef = new
HashMap<>();
+
+ ImmutableBitSet columnBits = RelOptUtil.InputFinder.bits(condition);
+ if (columnBits.isEmpty()) {
+ return condition;
+ }
+
+ // Trace which table does the column referenced in the condition come from
+ for (int columnBit : columnBits.asList()) {
+ Set<RexNode> exprLineage =
+ mq.getExpressionLineage(
+ relNode,
+ RexInputRef.of(columnBit, fieldList));
+ // If mq.getExpressionLineage cannot get result, skip it
+ if (exprLineage == null) {
+ continue;
+ }
+ Set<RexTableInputRef.RelTableRef> relTableRefs =
+ RexUtil.gatherTableReferences(Lists.newArrayList(exprLineage));
+ // If the column comes from multiple tables, skip it
+ if (relTableRefs.isEmpty() || relTableRefs.size() > 1) {
+ continue;
+ }
+ inputRefToTableRef.put(columnBit, relTableRefs.iterator().next());
+ }
+
+ ExpandDisjunctionForTableHelper expandHelper =
+ new ExpandDisjunctionForTableHelper(inputRefToTableRef, relBuilder,
config.bloat());
+ Map<RexTableInputRef.RelTableRef, RexNode> expandResult =
expandHelper.expand(condition);
+
+ RexNode newCondition = condition;
+ for (RexNode expandCondition : expandResult.values()) {
+ newCondition = relBuilder.and(newCondition, expandCondition);
+ }
+ return newCondition;
+ }
+
+ private static void matchFilter(ExpandDisjunctionForTableRule rule,
RelOptRuleCall call) {
+ Filter filter = call.rel(0);
+ RelMetadataQuery mq = call.getMetadataQuery();
+ RelBuilder relBuilder = call.builder();
+
+ RexNode newCondition =
+ rule.apply(
+ filter.getCondition(),
+ filter,
+ filter.getRowType().getFieldList(),
+ relBuilder,
+ mq);
+ if (newCondition.equals(filter.getCondition())) {
+ return;
+ }
+ Filter newFilter = filter.copy(filter.getTraitSet(), filter.getInput(),
newCondition);
+ call.transformTo(newFilter);
+ }
+
+ private static void matchJoin(ExpandDisjunctionForTableRule rule,
RelOptRuleCall call) {
+ Join join = call.rel(0);
+ RelMetadataQuery mq = call.getMetadataQuery();
+ RelBuilder relBuilder = call.builder();
+
+ List<RelDataTypeField> fieldList =
+ Lists.newArrayList(join.getLeft().getRowType().getFieldList());
+ fieldList.addAll(join.getRight().getRowType().getFieldList());
+ RexNode newCondition =
+ rule.apply(
+ join.getCondition(),
+ join,
+ fieldList,
+ relBuilder,
+ mq);
+ if (newCondition.equals(join.getCondition())) {
+ return;
+ }
+ Join newJoin =
+ join.copy(
+ join.getTraitSet(),
+ newCondition,
+ join.getLeft(),
+ join.getRight(),
+ join.getJoinType(),
+ join.isSemiJoinDone());
+ call.transformTo(newJoin);
+ }
+
+ /**
+ * Helper class to expand predicates.
+ */
+ private static class ExpandDisjunctionForTableHelper {
+ private final Map<Integer, RexTableInputRef.RelTableRef>
inputRefToTableRef;
+
+ private final RelBuilder relBuilder;
+
+ private final int maxNodeCount;
+
+ // Used to record the number of redundant expressions expanded.
+ private int currentCount;
+
+ private ExpandDisjunctionForTableHelper(
+ Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef,
+ RelBuilder relBuilder,
+ int maxNodeCount) {
+ this.inputRefToTableRef = inputRefToTableRef;
+ this.relBuilder = relBuilder;
+ this.maxNodeCount = maxNodeCount;
+ }
+
+ private Map<RexTableInputRef.RelTableRef, RexNode> expand(RexNode
condition) {
+ try {
+ this.currentCount = 0;
+ return expandDeep(condition);
+ } catch (OverLimitException e) {
+ return new HashMap<>();
+ }
+ }
+
+ /**
+ * Expand predicates recursively that can be pushed down to single table.
+ *
+ * @param condition Predicate to be expanded
+ * @return A map from a table to a (combined) predicate that can be
pushed down
+ * and only depends on columns of the table
+ */
+ private Map<RexTableInputRef.RelTableRef, RexNode> expandDeep(RexNode
condition) {
+ Map<RexTableInputRef.RelTableRef, RexNode> additionalConditions = new
HashMap<>();
+
+ ImmutableBitSet inputRefs = RelOptUtil.InputFinder.bits(condition);
+ if (inputRefs.isEmpty()) {
+ return additionalConditions;
+ }
+
+ RexTableInputRef.RelTableRef tableRef =
inputRefsBelongToOneTable(inputRefs);
+ if (tableRef != null) {
+ // The condition already belongs to one table, return it directly
+ checkExpandCount(condition.nodeCount());
+ additionalConditions.put(tableRef, condition);
+ return additionalConditions;
+ }
+
+ // Recursively expand the expression according to whether it is a
conjunction
+ // or a disjunction. If it is neither a disjunction nor a conjunction,
it cannot
+ // be expanded further and an empty Map is returned.
+ switch (condition.getKind()) {
+ case AND:
+ List<RexNode> andOperands = RexUtil.flattenAnd(((RexCall)
condition).getOperands());
+ for (RexNode andOperand : andOperands) {
+ Map<RexTableInputRef.RelTableRef, RexNode> operandResult =
expandDeep(andOperand);
+ combinePredicatesUsingAnd(additionalConditions, operandResult);
+ }
+ break;
+ case OR:
+ List<RexNode> orOperands = RexUtil.flattenOr(((RexCall)
condition).getOperands());
+ additionalConditions.putAll(expandDeep(orOperands.get(0)));
+ for (int i = 1; i < orOperands.size(); i++) {
+ Map<RexTableInputRef.RelTableRef, RexNode> operandResult =
+ expandDeep(orOperands.get(i));
+ combinePredicatesUsingOr(additionalConditions, operandResult);
+
+ if (additionalConditions.isEmpty()) {
+ break;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+
+ return additionalConditions;
+ }
+
+ private RexTableInputRef.@Nullable RelTableRef inputRefsBelongToOneTable(
+ ImmutableBitSet inputRefs) {
+ RexTableInputRef.RelTableRef tableRef =
inputRefToTableRef.get(inputRefs.nth(0));
+ if (tableRef == null) {
+ return null;
+ }
+ for (int inputBit : inputRefs.asList()) {
+ RexTableInputRef.RelTableRef inputBitTableRef =
inputRefToTableRef.get(inputBit);
+ if (!tableRef.equals(inputBitTableRef)) {
+ return null;
+ }
+ }
+ return tableRef;
+ }
+
+ /**
+ * Combine predicates that depend on the same table using conjunctions, and
+ * specify that the result is returned by modifying baseMap. For example:
+ *
+ * <p>baseMap: {t1: p1, t2: p2}
+ *
+ * <p>forMergeMap: {t1: p11, t3: p3}
+ *
+ * <p>result: {t1: p1 AND p11, t2: p2, t3: p3}
+ *
+ * @param baseMap Additional predicates that current conjunction has
already saved
+ * @param forMergeMap Additional predicates that current operand has
expanded
+ */
+ private void combinePredicatesUsingAnd(
+ Map<RexTableInputRef.RelTableRef, RexNode> baseMap,
+ Map<RexTableInputRef.RelTableRef, RexNode> forMergeMap) {
+ for (Map.Entry<RexTableInputRef.RelTableRef, RexNode> entry :
forMergeMap.entrySet()) {
+ RexNode mergedRex =
+ relBuilder.and(
+ entry.getValue(),
+ baseMap.getOrDefault(entry.getKey(),
relBuilder.literal(true)));
+ int oriCount = entry.getValue().nodeCount()
+ + (baseMap.containsKey(entry.getKey())
+ ? baseMap.get(entry.getKey()).nodeCount()
+ : 0);
+ checkExpandCount(mergedRex.nodeCount() - oriCount);
+ baseMap.put(entry.getKey(), mergedRex);
+ }
+ }
+
+ /**
+ * Combine predicates that depend on the same table using disjunctions, and
Review Comment:
same change as above.
##########
core/src/main/java/org/apache/calcite/rel/rules/ExpandDisjunctionForTableRule.java:
##########
@@ -0,0 +1,429 @@
+/*
+ * 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.Filter;
+import org.apache.calcite.rel.core.Join;
+import org.apache.calcite.rel.metadata.RelMetadataQuery;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexTableInputRef;
+import org.apache.calcite.rex.RexUtil;
+import org.apache.calcite.tools.RelBuilder;
+import org.apache.calcite.util.ControlFlowException;
+import org.apache.calcite.util.ImmutableBitSet;
+
+import com.google.common.collect.Lists;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.immutables.value.Value;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Rule to expand disjunction for single table in condition of a {@link
Filter} or {@link Join},
+ * It makes sense to make this optimization part of the predicate pushdown.
For example:
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * }</pre></blockquote>
+ *
+ * <p>we can expand to obtain the condition
+ *
+ * <blockquote><pre>{@code
+ * select t1.name from t1, t2
+ * where t1.id = t2.id
+ * and (
+ * (t1.id > 20 and t2.height < 50)
+ * or
+ * (t1.weight < 200 and t2.sales > 100)
+ * )
+ * and (t1.id > 20 or t1.weight < 200)
+ * and (t2.height < 50 or t2.sales > 100)
+ * }</pre></blockquote>
+ *
+ * <p>new generated predicates are redundant, but they could be pushed down to
+ * scan operator of t1/t2 and reduce the cardinality.
+ *
+ * <p>Note: This rule should only be applied once and it should be used before
+ * {@link CoreRules#FILTER_INTO_JOIN} and {@link
CoreRules#JOIN_CONDITION_PUSH}.
+ * In order to avoid it interacting with other expression-related rules and
causing
+ * an infinite loop, it is recommended to use it alone in HepPlanner first,
+ * and then do predicate pushdown.
+ *
+ * @see CoreRules#EXPAND_FILTER_DISJUNCTION_GLOBAL
+ * @see CoreRules#EXPAND_JOIN_DISJUNCTION_GLOBAL
+ */
[email protected]
+public class ExpandDisjunctionForTableRule
+ extends RelRule<ExpandDisjunctionForTableRule.Config>
+ implements TransformationRule {
+
+ /**
+ * Creates a ExpandDisjunctionForTableRule.
+ */
+ protected ExpandDisjunctionForTableRule(Config config) {
+ super(config);
+ }
+
+ @Override public void onMatch(RelOptRuleCall call) {
+ config.matchHandler().accept(this, call);
+ }
+
+ /**
+ * Expand predicates for condition of a {@link Filter} or {@link Join}.
+ *
+ * @param condition Condition to be expanded in Filter or Join
+ * @param relNode The Filter or Join node
+ * @param fieldList The field list of the Filter or Join inputs.
+ * @param relBuilder Builder
+ * @param mq RelMetadataQuery, which is used to get the expression
lineage
+ *
+ * @return The redundant predicate expanded from the condition parameter. It
is formed by
+ * concatenating the predicates that can be pushed down to single table with
AND.
+ */
+ private RexNode apply(
+ RexNode condition,
+ RelNode relNode,
+ List<RelDataTypeField> fieldList,
+ RelBuilder relBuilder,
+ RelMetadataQuery mq) {
+ final Map<Integer, RexTableInputRef.RelTableRef> inputRefToTableRef = new
HashMap<>();
+
+ ImmutableBitSet columnBits = RelOptUtil.InputFinder.bits(condition);
+ if (columnBits.isEmpty()) {
+ return condition;
+ }
+
+ // Trace which table does the column referenced in the condition come from
Review Comment:
I think this is easier to read if written as
"for each table discover the conditions that refer to columns of that table
(and refer to no other tables)"
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