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Posted to commits@hive.apache.org by jc...@apache.org on 2016/12/16 13:58:29 UTC
[3/6] hive git commit: HIVE-14496: Enable Calcite rewriting with
materialized views (Jesus Camacho Rodriguez, reviewed by Ashutosh Chauhan)
http://git-wip-us.apache.org/repos/asf/hive/blob/3da29fe7/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/views/SubstitutionVisitor.java
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diff --git a/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/views/SubstitutionVisitor.java b/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/views/SubstitutionVisitor.java
new file mode 100644
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+++ b/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/views/SubstitutionVisitor.java
@@ -0,0 +1,2458 @@
+/**
+ * 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.hadoop.hive.ql.optimizer.calcite.rules.views;
+
+import static org.apache.calcite.rex.RexUtil.andNot;
+import static org.apache.calcite.rex.RexUtil.removeAll;
+import static org.apache.calcite.rex.RexUtil.simplify;
+
+import java.util.AbstractList;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+import org.apache.calcite.avatica.util.Spaces;
+import org.apache.calcite.linq4j.Ord;
+import org.apache.calcite.plan.RelOptCluster;
+import org.apache.calcite.plan.RelOptRule;
+import org.apache.calcite.plan.RelOptRuleCall;
+import org.apache.calcite.plan.RelOptUtil;
+import org.apache.calcite.plan.RexImplicationChecker;
+import org.apache.calcite.rel.RelCollation;
+import org.apache.calcite.rel.RelNode;
+import org.apache.calcite.rel.SingleRel;
+import org.apache.calcite.rel.core.Aggregate;
+import org.apache.calcite.rel.core.AggregateCall;
+import org.apache.calcite.rel.core.CorrelationId;
+import org.apache.calcite.rel.core.Filter;
+import org.apache.calcite.rel.core.Join;
+import org.apache.calcite.rel.core.JoinRelType;
+import org.apache.calcite.rel.core.Project;
+import org.apache.calcite.rel.core.RelFactories;
+import org.apache.calcite.rel.core.Sort;
+import org.apache.calcite.rel.core.TableScan;
+import org.apache.calcite.rel.core.Values;
+import org.apache.calcite.rel.logical.LogicalAggregate;
+import org.apache.calcite.rel.logical.LogicalJoin;
+import org.apache.calcite.rel.logical.LogicalSort;
+import org.apache.calcite.rel.logical.LogicalUnion;
+import org.apache.calcite.rel.type.RelDataType;
+import org.apache.calcite.rel.type.RelDataTypeField;
+import org.apache.calcite.rex.RexBuilder;
+import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.rex.RexExecutorImpl;
+import org.apache.calcite.rex.RexInputRef;
+import org.apache.calcite.rex.RexLiteral;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.rex.RexShuttle;
+import org.apache.calcite.rex.RexUtil;
+import org.apache.calcite.sql.SqlAggFunction;
+import org.apache.calcite.sql.fun.SqlStdOperatorTable;
+import org.apache.calcite.sql.validate.SqlValidatorUtil;
+import org.apache.calcite.tools.RelBuilder;
+import org.apache.calcite.tools.RelBuilderFactory;
+import org.apache.calcite.util.Bug;
+import org.apache.calcite.util.ControlFlowException;
+import org.apache.calcite.util.ImmutableBitSet;
+import org.apache.calcite.util.Litmus;
+import org.apache.calcite.util.Pair;
+import org.apache.calcite.util.Util;
+import org.apache.calcite.util.mapping.Mapping;
+import org.apache.calcite.util.mapping.Mappings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Equivalence;
+import com.google.common.base.Function;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Predicate;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.LinkedHashMultimap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
+
+/**
+ * Substitutes part of a tree of relational expressions with another tree.
+ *
+ * <p>The call {@code new SubstitutionVisitor(target, query).go(replacement))}
+ * will return {@code query} with every occurrence of {@code target} replaced
+ * by {@code replacement}.</p>
+ *
+ * <p>The following example shows how {@code SubstitutionVisitor} can be used
+ * for materialized view recognition.</p>
+ *
+ * <ul>
+ * <li>query = SELECT a, c FROM t WHERE x = 5 AND b = 4</li>
+ * <li>target = SELECT a, b, c FROM t WHERE x = 5</li>
+ * <li>replacement = SELECT * FROM mv</li>
+ * <li>result = SELECT a, c FROM mv WHERE b = 4</li>
+ * </ul>
+ *
+ * <p>Note that {@code result} uses the materialized view table {@code mv} and a
+ * simplified condition {@code b = 4}.</p>
+ *
+ * <p>Uses a bottom-up matching algorithm. Nodes do not need to be identical.
+ * At each level, returns the residue.</p>
+ *
+ * <p>The inputs must only include the core relational operators:
+ * {@link org.apache.calcite.rel.logical.LogicalTableScan},
+ * {@link org.apache.calcite.rel.logical.LogicalFilter},
+ * {@link org.apache.calcite.rel.logical.LogicalProject},
+ * {@link org.apache.calcite.rel.logical.LogicalJoin},
+ * {@link org.apache.calcite.rel.logical.LogicalUnion},
+ * {@link org.apache.calcite.rel.logical.LogicalAggregate}.</p>
+ *
+ * TODO: Remove when we upgrade to Calcite version using builders.
+ */
+public class SubstitutionVisitor {
+
+ private static final Logger LOGGER = LoggerFactory.getLogger(SubstitutionVisitor.class);
+
+ /** Equivalence that compares objects by their {@link Object#toString()}
+ * method. */
+ private static final Equivalence<Object> STRING_EQUIVALENCE =
+ new Equivalence<Object>() {
+ @Override protected boolean doEquivalent(Object o, Object o2) {
+ return o.toString().equals(o2.toString());
+ }
+
+ @Override protected int doHash(Object o) {
+ return o.toString().hashCode();
+ }
+ };
+
+ /** Equivalence that compares {@link Lists}s by the
+ * {@link Object#toString()} of their elements. */
+ @SuppressWarnings("unchecked")
+ private static final Equivalence<List<?>> PAIRWISE_STRING_EQUIVALENCE =
+ (Equivalence) STRING_EQUIVALENCE.pairwise();
+
+ protected static final ImmutableList<UnifyRule> DEFAULT_RULES =
+ ImmutableList.<UnifyRule>of(
+ TrivialRule.INSTANCE,
+ ScanToProjectUnifyRule.INSTANCE,
+ ProjectToProjectUnifyRule.INSTANCE,
+ FilterToProjectUnifyRule.INSTANCE,
+// ProjectToFilterUnifyRule.INSTANCE,
+// FilterToFilterUnifyRule.INSTANCE,
+ AggregateToAggregateUnifyRule.INSTANCE,
+ AggregateOnProjectToAggregateUnifyRule.INSTANCE);
+
+ /**
+ * Factory for a builder for relational expressions.
+ * <p>The actual builder is available via {@link RelOptRuleCall#builder()}.
+ */
+ protected final RelBuilder relBuilder;
+
+ private final ImmutableList<UnifyRule> rules;
+ private final Map<Pair<Class, Class>, List<UnifyRule>> ruleMap =
+ new HashMap<>();
+ private final RelOptCluster cluster;
+ private final Holder query;
+ private final MutableRel target;
+
+ /**
+ * Nodes in {@link #target} that have no children.
+ */
+ final List<MutableRel> targetLeaves;
+
+ /**
+ * Nodes in {@link #query} that have no children.
+ */
+ final List<MutableRel> queryLeaves;
+
+ final Map<MutableRel, MutableRel> replacementMap = new HashMap<>();
+
+ final Multimap<MutableRel, MutableRel> equivalents =
+ LinkedHashMultimap.create();
+
+ /** Workspace while rule is being matched.
+ * Careful, re-entrant!
+ * Assumes no rule needs more than 2 slots. */
+ protected final MutableRel[] slots = new MutableRel[2];
+
+ /** Creates a SubstitutionVisitor with the default rule set. */
+ public SubstitutionVisitor(RelNode target_, RelNode query_) {
+ this(target_, query_, DEFAULT_RULES);
+ }
+
+ public SubstitutionVisitor(RelNode target_, RelNode query_,
+ ImmutableList<UnifyRule> rules) {
+ this(target_, query_, rules, RelFactories.LOGICAL_BUILDER);
+ }
+
+ /** Creates a SubstitutionVisitor. */
+ public SubstitutionVisitor(RelNode target_, RelNode query_,
+ ImmutableList<UnifyRule> rules, RelBuilderFactory relBuilderFactory) {
+ this.cluster = target_.getCluster();
+ this.rules = rules;
+ this.query = Holder.of(toMutable(query_));
+ this.target = toMutable(target_);
+ this.relBuilder = relBuilderFactory.create(cluster, null);
+ final Set<MutableRel> parents = Sets.newIdentityHashSet();
+ final List<MutableRel> allNodes = new ArrayList<>();
+ final MutableRelVisitor visitor =
+ new MutableRelVisitor() {
+ public void visit(MutableRel node) {
+ parents.add(node.parent);
+ allNodes.add(node);
+ super.visit(node);
+ }
+ };
+ visitor.go(target);
+
+ // Populate the list of leaves in the tree under "target".
+ // Leaves are all nodes that are not parents.
+ // For determinism, it is important that the list is in scan order.
+ allNodes.removeAll(parents);
+ targetLeaves = ImmutableList.copyOf(allNodes);
+
+ allNodes.clear();
+ parents.clear();
+ visitor.go(query);
+ allNodes.removeAll(parents);
+ queryLeaves = ImmutableList.copyOf(allNodes);
+ }
+
+ private static MutableRel toMutable(RelNode rel) {
+ if (rel instanceof TableScan) {
+ return MutableScan.of((TableScan) rel);
+ }
+ if (rel instanceof Values) {
+ return MutableValues.of((Values) rel);
+ }
+ if (rel instanceof Project) {
+ final Project project = (Project) rel;
+ final MutableRel input = toMutable(project.getInput());
+ return MutableProject.of(input, project.getProjects(),
+ project.getRowType().getFieldNames());
+ }
+ if (rel instanceof Filter) {
+ final Filter filter = (Filter) rel;
+ final MutableRel input = toMutable(filter.getInput());
+ return MutableFilter.of(input, filter.getCondition());
+ }
+ if (rel instanceof Aggregate) {
+ final Aggregate aggregate = (Aggregate) rel;
+ final MutableRel input = toMutable(aggregate.getInput());
+ return MutableAggregate.of(input, aggregate.indicator,
+ aggregate.getGroupSet(), aggregate.getGroupSets(),
+ aggregate.getAggCallList());
+ }
+ if (rel instanceof Join) {
+ final Join join = (Join) rel;
+ final MutableRel left = toMutable(join.getLeft());
+ final MutableRel right = toMutable(join.getRight());
+ return MutableJoin.of(join.getCluster(), left, right,
+ join.getCondition(), join.getJoinType(), join.getVariablesSet());
+ }
+ if (rel instanceof Sort) {
+ final Sort sort = (Sort) rel;
+ final MutableRel input = toMutable(sort.getInput());
+ return MutableSort.of(input, sort.getCollation(), sort.offset, sort.fetch);
+ }
+ throw new RuntimeException("cannot translate " + rel + " to MutableRel");
+ }
+
+ void register(MutableRel result, MutableRel query) {
+ }
+
+ /**
+ * Maps a condition onto a target.
+ *
+ * <p>If condition is stronger than target, returns the residue.
+ * If it is equal to target, returns the expression that evaluates to
+ * the constant {@code true}. If it is weaker than target, returns
+ * {@code null}.</p>
+ *
+ * <p>The terms satisfy the relation</p>
+ *
+ * <pre>
+ * {@code condition = target AND residue}
+ * </pre>
+ *
+ * <p>and {@code residue} must be as weak as possible.</p>
+ *
+ * <p>Example #1: condition stronger than target</p>
+ * <ul>
+ * <li>condition: x = 1 AND y = 2</li>
+ * <li>target: x = 1</li>
+ * <li>residue: y = 2</li>
+ * </ul>
+ *
+ * <p>Note that residue {@code x > 0 AND y = 2} would also satisfy the
+ * relation {@code condition = target AND residue} but is stronger than
+ * necessary, so we prefer {@code y = 2}.</p>
+ *
+ * <p>Example #2: target weaker than condition (valid, but not currently
+ * implemented)</p>
+ * <ul>
+ * <li>condition: x = 1</li>
+ * <li>target: x = 1 OR z = 3</li>
+ * <li>residue: NOT (z = 3)</li>
+ * </ul>
+ *
+ * <p>Example #3: condition and target are equivalent</p>
+ * <ul>
+ * <li>condition: x = 1 AND y = 2</li>
+ * <li>target: y = 2 AND x = 1</li>
+ * <li>residue: TRUE</li>
+ * </ul>
+ *
+ * <p>Example #4: condition weaker than target</p>
+ * <ul>
+ * <li>condition: x = 1</li>
+ * <li>target: x = 1 AND y = 2</li>
+ * <li>residue: null (i.e. no match)</li>
+ * </ul>
+ *
+ * <p>There are many other possible examples. It amounts to solving
+ * whether {@code condition AND NOT target} can ever evaluate to
+ * true, and therefore is a form of the NP-complete
+ * <a href="http://en.wikipedia.org/wiki/Satisfiability">Satisfiability</a>
+ * problem.</p>
+ */
+ @VisibleForTesting
+ public static RexNode splitFilter(
+ final RexBuilder rexBuilder, RexNode condition, RexNode target) {
+ // First, try splitting into ORs.
+ // Given target c1 OR c2 OR c3 OR c4
+ // and condition c2 OR c4
+ // residue is NOT c1 AND NOT c3
+ // Also deals with case target [x] condition [x] yields residue [true].
+ RexNode z = splitOr(rexBuilder, condition, target);
+ if (z != null) {
+ return z;
+ }
+
+ RexNode x = andNot(rexBuilder, target, condition);
+ if (mayBeSatisfiable(x)) {
+ RexNode x2 = andNot(rexBuilder, condition, target);
+ return simplify(rexBuilder, x2);
+ }
+ return null;
+ }
+
+ private static RexNode splitOr(
+ final RexBuilder rexBuilder, RexNode condition, RexNode target) {
+ List<RexNode> targets = RelOptUtil.disjunctions(target);
+ for (RexNode e : RelOptUtil.disjunctions(condition)) {
+ boolean found = removeAll(targets, e);
+ if (!found) {
+ return null;
+ }
+ }
+ return RexUtil.composeConjunction(rexBuilder,
+ Lists.transform(targets, RexUtil.notFn(rexBuilder)), false);
+ }
+
+ /**
+ * Returns whether a boolean expression ever returns true.
+ *
+ * <p>This method may give false positives. For instance, it will say
+ * that {@code x = 5 AND x > 10} is satisfiable, because at present it
+ * cannot prove that it is not.</p>
+ */
+ public static boolean mayBeSatisfiable(RexNode e) {
+ // Example:
+ // e: x = 1 AND y = 2 AND z = 3 AND NOT (x = 1 AND y = 2)
+ // disjunctions: {x = 1, y = 2, z = 3}
+ // notDisjunctions: {x = 1 AND y = 2}
+ final List<RexNode> disjunctions = new ArrayList<>();
+ final List<RexNode> notDisjunctions = new ArrayList<>();
+ RelOptUtil.decomposeConjunction(e, disjunctions, notDisjunctions);
+
+ // If there is a single FALSE or NOT TRUE, the whole expression is
+ // always false.
+ for (RexNode disjunction : disjunctions) {
+ switch (disjunction.getKind()) {
+ case LITERAL:
+ if (!RexLiteral.booleanValue(disjunction)) {
+ return false;
+ }
+ }
+ }
+ for (RexNode disjunction : notDisjunctions) {
+ switch (disjunction.getKind()) {
+ case LITERAL:
+ if (RexLiteral.booleanValue(disjunction)) {
+ return false;
+ }
+ }
+ }
+ // If one of the not-disjunctions is a disjunction that is wholly
+ // contained in the disjunctions list, the expression is not
+ // satisfiable.
+ //
+ // Example #1. x AND y AND z AND NOT (x AND y) - not satisfiable
+ // Example #2. x AND y AND NOT (x AND y) - not satisfiable
+ // Example #3. x AND y AND NOT (x AND y AND z) - may be satisfiable
+ for (RexNode notDisjunction : notDisjunctions) {
+ final List<RexNode> disjunctions2 =
+ RelOptUtil.conjunctions(notDisjunction);
+ if (disjunctions.containsAll(disjunctions2)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ public RelNode go0(RelNode replacement_) {
+ assert false; // not called
+ MutableRel replacement = toMutable(replacement_);
+ assert MutableRels.equalType(
+ "target", target, "replacement", replacement, Litmus.THROW);
+ replacementMap.put(target, replacement);
+ final UnifyResult unifyResult = matchRecurse(target);
+ if (unifyResult == null) {
+ return null;
+ }
+ final MutableRel node0 = unifyResult.result;
+ MutableRel node = node0; // replaceAncestors(node0);
+ if (LOGGER.isDebugEnabled()) {
+ LOGGER.debug("Convert: query:\n"
+ + query.deep()
+ + "\nunify.query:\n"
+ + unifyResult.call.query.deep()
+ + "\nunify.result:\n"
+ + unifyResult.result.deep()
+ + "\nunify.target:\n"
+ + unifyResult.call.target.deep()
+ + "\nnode0:\n"
+ + node0.deep()
+ + "\nnode:\n"
+ + node.deep());
+ }
+ return fromMutable(node);
+ }
+
+ /**
+ * Returns a list of all possible rels that result from substituting the
+ * matched RelNode with the replacement RelNode within the query.
+ *
+ * <p>For example, the substitution result of A join B, while A and B
+ * are both a qualified match for replacement R, is R join B, R join R,
+ * A join R.
+ */
+ public List<RelNode> go(RelNode replacement_) {
+ List<List<Replacement>> matches = go(toMutable(replacement_));
+ if (matches.isEmpty()) {
+ return ImmutableList.of();
+ }
+ List<RelNode> sub = Lists.newArrayList();
+ sub.add(fromMutable(query.input));
+ reverseSubstitute(query, matches, sub, 0, matches.size());
+ return sub;
+ }
+
+ /**
+ * Substitutes the query with replacement whenever possible but meanwhile
+ * keeps track of all the substitutions and their original rel before
+ * replacement, so that in later processing stage, the replacement can be
+ * recovered individually to produce a list of all possible rels with
+ * substitution in different places.
+ */
+ private List<List<Replacement>> go(MutableRel replacement) {
+ assert MutableRels.equalType(
+ "target", target, "replacement", replacement, Litmus.THROW);
+ final List<MutableRel> queryDescendants = MutableRels.descendants(query);
+ final List<MutableRel> targetDescendants = MutableRels.descendants(target);
+
+ // Populate "equivalents" with (q, t) for each query descendant q and
+ // target descendant t that are equal.
+ final Map<MutableRel, MutableRel> map = Maps.newHashMap();
+ for (MutableRel queryDescendant : queryDescendants) {
+ map.put(queryDescendant, queryDescendant);
+ }
+ for (MutableRel targetDescendant : targetDescendants) {
+ MutableRel queryDescendant = map.get(targetDescendant);
+ if (queryDescendant != null) {
+ assert queryDescendant.rowType.equals(targetDescendant.rowType);
+ equivalents.put(queryDescendant, targetDescendant);
+ }
+ }
+ map.clear();
+
+ final List<Replacement> attempted = Lists.newArrayList();
+ List<List<Replacement>> substitutions = Lists.newArrayList();
+
+ for (;;) {
+ int count = 0;
+ MutableRel queryDescendant = query;
+ outer:
+ while (queryDescendant != null) {
+ for (Replacement r : attempted) {
+ if (queryDescendant == r.after) {
+ // This node has been replaced by previous iterations in the
+ // hope to match its ancestors, so the node itself should not
+ // be matched again.
+ queryDescendant = MutableRels.preOrderTraverseNext(queryDescendant);
+ continue outer;
+ }
+ }
+ final MutableRel next = MutableRels.preOrderTraverseNext(queryDescendant);
+ final MutableRel childOrNext =
+ queryDescendant.getInputs().isEmpty()
+ ? next : queryDescendant.getInputs().get(0);
+ for (MutableRel targetDescendant : targetDescendants) {
+ for (UnifyRule rule
+ : applicableRules(queryDescendant, targetDescendant)) {
+ UnifyRuleCall call =
+ rule.match(this, queryDescendant, targetDescendant);
+ if (call != null) {
+ final UnifyResult result = rule.apply(call);
+ if (result != null) {
+ ++count;
+ attempted.add(new Replacement(result.call.query, result.result));
+ MutableRel parent = result.call.query.replaceInParent(result.result);
+
+ // Replace previous equivalents with new equivalents, higher up
+ // the tree.
+ for (int i = 0; i < rule.slotCount; i++) {
+ Collection<MutableRel> equi = equivalents.get(slots[i]);
+ if (!equi.isEmpty()) {
+ equivalents.remove(slots[i], equi.iterator().next());
+ }
+ }
+ assert result.result.rowType.equals(result.call.query.rowType)
+ : Pair.of(result.result, result.call.query);
+ equivalents.put(result.result, result.call.query);
+ if (targetDescendant == target) {
+ // A real substitution happens. We purge the attempted
+ // replacement list and add them into substitution list.
+ // Meanwhile we stop matching the descendants and jump
+ // to the next subtree in pre-order traversal.
+ if (!target.equals(replacement)) {
+ Replacement r = MutableRels.replace(
+ query.input, target, copyMutable(replacement));
+ assert r != null
+ : rule + "should have returned a result containing the target.";
+ attempted.add(r);
+ }
+ substitutions.add(ImmutableList.copyOf(attempted));
+ attempted.clear();
+ queryDescendant = next;
+ continue outer;
+ }
+ // We will try walking the query tree all over again to see
+ // if there can be any substitutions after the replacement
+ // attempt.
+ break outer;
+ }
+ }
+ }
+ }
+ queryDescendant = childOrNext;
+ }
+ // Quit the entire loop if:
+ // 1) we have walked the entire query tree with one or more successful
+ // substitutions, thus count != 0 && attempted.isEmpty();
+ // 2) we have walked the entire query tree but have made no replacement
+ // attempt, thus count == 0 && attempted.isEmpty();
+ // 3) we had done some replacement attempt in a previous walk, but in
+ // this one we have not found any potential matches or substitutions,
+ // thus count == 0 && !attempted.isEmpty().
+ if (count == 0 || attempted.isEmpty()) {
+ break;
+ }
+ }
+ if (!attempted.isEmpty()) {
+ // We had done some replacement attempt in the previous walk, but that
+ // did not lead to any substitutions in this walk, so we need to recover
+ // the replacement.
+ undoReplacement(attempted);
+ }
+ return substitutions;
+ }
+
+ /**
+ * Represents a replacement action: before → after.
+ */
+ private static class Replacement {
+ final MutableRel before;
+ final MutableRel after;
+
+ Replacement(MutableRel before, MutableRel after) {
+ this.before = before;
+ this.after = after;
+ }
+ }
+
+ private static void undoReplacement(List<Replacement> replacement) {
+ for (int i = replacement.size() - 1; i >= 0; i--) {
+ Replacement r = replacement.get(i);
+ r.after.replaceInParent(r.before);
+ }
+ }
+
+ private static void redoReplacement(List<Replacement> replacement) {
+ for (Replacement r : replacement) {
+ r.before.replaceInParent(r.after);
+ }
+ }
+
+ private void reverseSubstitute(Holder query,
+ List<List<Replacement>> matches, List<RelNode> sub,
+ int replaceCount, int maxCount) {
+ if (matches.isEmpty()) {
+ return;
+ }
+ final List<List<Replacement>> rem = matches.subList(1, matches.size());
+ reverseSubstitute(query, rem, sub, replaceCount, maxCount);
+ undoReplacement(matches.get(0));
+ if (++replaceCount < maxCount) {
+ sub.add(fromMutable(query.input));
+ }
+ reverseSubstitute(query, rem, sub, replaceCount, maxCount);
+ redoReplacement(matches.get(0));
+ }
+
+ private List<RelNode> fromMutables(List<MutableRel> nodes) {
+ return Lists.transform(nodes,
+ new Function<MutableRel, RelNode>() {
+ public RelNode apply(MutableRel mutableRel) {
+ return fromMutable(mutableRel);
+ }
+ });
+ }
+
+ private RelNode fromMutable(MutableRel node) {
+ switch (node.type) {
+ case SCAN:
+ case VALUES:
+ return ((MutableLeafRel) node).rel;
+ case PROJECT:
+ final MutableProject project = (MutableProject) node;
+ relBuilder.push(fromMutable(project.input));
+ relBuilder.project(project.projects);
+ return relBuilder.build();
+ case FILTER:
+ final MutableFilter filter = (MutableFilter) node;
+ relBuilder.push(fromMutable(filter.input));
+ relBuilder.filter(filter.condition);
+ return relBuilder.build();
+ case AGGREGATE:
+ final MutableAggregate aggregate = (MutableAggregate) node;
+ return LogicalAggregate.create(fromMutable(aggregate.input),
+ aggregate.indicator, aggregate.groupSet, aggregate.groupSets,
+ aggregate.aggCalls);
+ case SORT:
+ final MutableSort sort = (MutableSort) node;
+ return LogicalSort.create(fromMutable(sort.input), sort.collation,
+ sort.offset, sort.fetch);
+ case UNION:
+ final MutableUnion union = (MutableUnion) node;
+ return LogicalUnion.create(fromMutables(union.inputs), union.all);
+ case JOIN:
+ final MutableJoin join = (MutableJoin) node;
+ return LogicalJoin.create(fromMutable(join.getLeft()), fromMutable(join.getRight()),
+ join.getCondition(), join.getVariablesSet(), join.getJoinType());
+ default:
+ throw new AssertionError(node.deep());
+ }
+ }
+
+ private static List<MutableRel> copyMutables(List<MutableRel> nodes) {
+ return Lists.transform(nodes,
+ new Function<MutableRel, MutableRel>() {
+ public MutableRel apply(MutableRel mutableRel) {
+ return copyMutable(mutableRel);
+ }
+ });
+ }
+
+ private static MutableRel copyMutable(MutableRel node) {
+ switch (node.type) {
+ case SCAN:
+ return MutableScan.of((TableScan) ((MutableScan) node).rel);
+ case VALUES:
+ return MutableValues.of((Values) ((MutableValues) node).rel);
+ case PROJECT:
+ final MutableProject project = (MutableProject) node;
+ return MutableProject.of(project.rowType,
+ copyMutable(project.input), project.projects);
+ case FILTER:
+ final MutableFilter filter = (MutableFilter) node;
+ return MutableFilter.of(copyMutable(filter.input), filter.condition);
+ case AGGREGATE:
+ final MutableAggregate aggregate = (MutableAggregate) node;
+ return MutableAggregate.of(copyMutable(aggregate.input),
+ aggregate.indicator, aggregate.groupSet, aggregate.groupSets,
+ aggregate.aggCalls);
+ case SORT:
+ final MutableSort sort = (MutableSort) node;
+ return MutableSort.of(copyMutable(sort.input), sort.collation,
+ sort.offset, sort.fetch);
+ case UNION:
+ final MutableUnion union = (MutableUnion) node;
+ return MutableUnion.of(copyMutables(union.inputs), union.all);
+ case JOIN:
+ final MutableJoin join = (MutableJoin) node;
+ return MutableJoin.of(join.cluster, copyMutable(join.getLeft()),
+ copyMutable(join.getRight()), join.getCondition(), join.getJoinType(),
+ join.getVariablesSet());
+ default:
+ throw new AssertionError(node.deep());
+ }
+ }
+
+ private UnifyResult matchRecurse(MutableRel target) {
+ assert false; // not called
+ final List<MutableRel> targetInputs = target.getInputs();
+ MutableRel queryParent = null;
+
+ for (MutableRel targetInput : targetInputs) {
+ UnifyResult unifyResult = matchRecurse(targetInput);
+ if (unifyResult == null) {
+ return null;
+ }
+ queryParent = unifyResult.call.query.replaceInParent(unifyResult.result);
+ }
+
+ if (targetInputs.isEmpty()) {
+ for (MutableRel queryLeaf : queryLeaves) {
+ for (UnifyRule rule : applicableRules(queryLeaf, target)) {
+ final UnifyResult x = apply(rule, queryLeaf, target);
+ if (x != null) {
+ if (LOGGER.isDebugEnabled()) {
+ LOGGER.debug("Rule: " + rule
+ + "\nQuery:\n"
+ + queryParent
+ + (x.call.query != queryParent
+ ? "\nQuery (original):\n"
+ + queryParent
+ : "")
+ + "\nTarget:\n"
+ + target.deep()
+ + "\nResult:\n"
+ + x.result.deep()
+ + "\n");
+ }
+ return x;
+ }
+ }
+ }
+ } else {
+ assert queryParent != null;
+ for (UnifyRule rule : applicableRules(queryParent, target)) {
+ final UnifyResult x = apply(rule, queryParent, target);
+ if (x != null) {
+ if (LOGGER.isDebugEnabled()) {
+ LOGGER.debug(
+ "Rule: " + rule
+ + "\nQuery:\n"
+ + queryParent.deep()
+ + (x.call.query != queryParent
+ ? "\nQuery (original):\n"
+ + queryParent.toString()
+ : "")
+ + "\nTarget:\n"
+ + target.deep()
+ + "\nResult:\n"
+ + x.result.deep()
+ + "\n");
+ }
+ return x;
+ }
+ }
+ }
+ if (LOGGER.isDebugEnabled()) {
+ LOGGER.debug(
+ "Unify failed:"
+ + "\nQuery:\n"
+ + queryParent.toString()
+ + "\nTarget:\n"
+ + target.toString()
+ + "\n");
+ }
+ return null;
+ }
+
+ private UnifyResult apply(UnifyRule rule, MutableRel query,
+ MutableRel target) {
+ final UnifyRuleCall call = new UnifyRuleCall(rule, query, target, null);
+ return rule.apply(call);
+ }
+
+ private List<UnifyRule> applicableRules(MutableRel query,
+ MutableRel target) {
+ final Class queryClass = query.getClass();
+ final Class targetClass = target.getClass();
+ final Pair<Class, Class> key = Pair.of(queryClass, targetClass);
+ List<UnifyRule> list = ruleMap.get(key);
+ if (list == null) {
+ final ImmutableList.Builder<UnifyRule> builder =
+ ImmutableList.builder();
+ for (UnifyRule rule : rules) {
+ //noinspection unchecked
+ if (mightMatch(rule, queryClass, targetClass)) {
+ builder.add(rule);
+ }
+ }
+ list = builder.build();
+ ruleMap.put(key, list);
+ }
+ return list;
+ }
+
+ private static boolean mightMatch(UnifyRule rule,
+ Class queryClass, Class targetClass) {
+ return rule.queryOperand.clazz.isAssignableFrom(queryClass)
+ && rule.targetOperand.clazz.isAssignableFrom(targetClass);
+ }
+
+ /** Exception thrown to exit a matcher. Not really an error. */
+ protected static class MatchFailed extends ControlFlowException {
+ @SuppressWarnings("ThrowableInstanceNeverThrown")
+ public static final MatchFailed INSTANCE = new MatchFailed();
+ }
+
+ /** Rule that attempts to match a query relational expression
+ * against a target relational expression.
+ *
+ * <p>The rule declares the query and target types; this allows the
+ * engine to fire only a few rules in a given context.</p>
+ */
+ protected abstract static class UnifyRule {
+ protected final int slotCount;
+ protected final Operand queryOperand;
+ protected final Operand targetOperand;
+
+ protected UnifyRule(int slotCount, Operand queryOperand,
+ Operand targetOperand) {
+ this.slotCount = slotCount;
+ this.queryOperand = queryOperand;
+ this.targetOperand = targetOperand;
+ }
+
+ /**
+ * <p>Applies this rule to a particular node in a query. The goal is
+ * to convert {@code query} into {@code target}. Before the rule is
+ * invoked, Calcite has made sure that query's children are equivalent
+ * to target's children.
+ *
+ * <p>There are 3 possible outcomes:</p>
+ *
+ * <ul>
+ *
+ * <li>{@code query} already exactly matches {@code target}; returns
+ * {@code target}</li>
+ *
+ * <li>{@code query} is sufficiently close to a match for
+ * {@code target}; returns {@code target}</li>
+ *
+ * <li>{@code query} cannot be made to match {@code target}; returns
+ * null</li>
+ *
+ * </ul>
+ *
+ * <p>REVIEW: Is possible that we match query PLUS one or more of its
+ * ancestors?</p>
+ *
+ * @param call Input parameters
+ */
+ protected abstract UnifyResult apply(UnifyRuleCall call);
+
+ protected UnifyRuleCall match(SubstitutionVisitor visitor, MutableRel query,
+ MutableRel target) {
+ if (queryOperand.matches(visitor, query)) {
+ if (targetOperand.matches(visitor, target)) {
+ return visitor.new UnifyRuleCall(this, query, target,
+ copy(visitor.slots, slotCount));
+ }
+ }
+ return null;
+ }
+
+ protected <E> ImmutableList<E> copy(E[] slots, int slotCount) {
+ // Optimize if there are 0 or 1 slots.
+ switch (slotCount) {
+ case 0:
+ return ImmutableList.of();
+ case 1:
+ return ImmutableList.of(slots[0]);
+ default:
+ return ImmutableList.copyOf(slots).subList(0, slotCount);
+ }
+ }
+ }
+
+ /**
+ * Arguments to an application of a {@link UnifyRule}.
+ */
+ protected class UnifyRuleCall {
+ protected final UnifyRule rule;
+ public final MutableRel query;
+ public final MutableRel target;
+ protected final ImmutableList<MutableRel> slots;
+
+ public UnifyRuleCall(UnifyRule rule, MutableRel query, MutableRel target,
+ ImmutableList<MutableRel> slots) {
+ this.rule = Preconditions.checkNotNull(rule);
+ this.query = Preconditions.checkNotNull(query);
+ this.target = Preconditions.checkNotNull(target);
+ this.slots = Preconditions.checkNotNull(slots);
+ }
+
+ public UnifyResult result(MutableRel result) {
+ assert MutableRels.contains(result, target);
+ assert MutableRels.equalType("result", result, "query", query,
+ Litmus.THROW);
+ MutableRel replace = replacementMap.get(target);
+ if (replace != null) {
+ assert false; // replacementMap is always empty
+ // result =
+ MutableRels.replace(result, target, replace);
+ }
+ register(result, query);
+ return new UnifyResult(this, result);
+ }
+
+ /**
+ * Creates a {@link UnifyRuleCall} based on the parent of {@code query}.
+ */
+ public UnifyRuleCall create(MutableRel query) {
+ return new UnifyRuleCall(rule, query, target, slots);
+ }
+
+ public RelOptCluster getCluster() {
+ return cluster;
+ }
+ }
+
+ /**
+ * Result of an application of a {@link UnifyRule} indicating that the
+ * rule successfully matched {@code query} against {@code target} and
+ * generated a {@code result} that is equivalent to {@code query} and
+ * contains {@code target}.
+ */
+ protected static class UnifyResult {
+ private final UnifyRuleCall call;
+ // equivalent to "query", contains "result"
+ private final MutableRel result;
+
+ UnifyResult(UnifyRuleCall call, MutableRel result) {
+ this.call = call;
+ assert MutableRels.equalType("query", call.query, "result", result,
+ Litmus.THROW);
+ this.result = result;
+ }
+ }
+
+ /** Abstract base class for implementing {@link UnifyRule}. */
+ protected abstract static class AbstractUnifyRule extends UnifyRule {
+ public AbstractUnifyRule(Operand queryOperand, Operand targetOperand,
+ int slotCount) {
+ super(slotCount, queryOperand, targetOperand);
+ //noinspection AssertWithSideEffects
+ assert isValid();
+ }
+
+ protected boolean isValid() {
+ final SlotCounter slotCounter = new SlotCounter();
+ slotCounter.visit(queryOperand);
+ assert slotCounter.queryCount == slotCount;
+ assert slotCounter.targetCount == 0;
+ slotCounter.queryCount = 0;
+ slotCounter.visit(targetOperand);
+ assert slotCounter.queryCount == 0;
+ assert slotCounter.targetCount == slotCount;
+ return true;
+ }
+
+ /** Creates an operand with given inputs. */
+ protected static Operand operand(Class<? extends MutableRel> clazz,
+ Operand... inputOperands) {
+ return new InternalOperand(clazz, ImmutableList.copyOf(inputOperands));
+ }
+
+ /** Creates an operand that doesn't check inputs. */
+ protected static Operand any(Class<? extends MutableRel> clazz) {
+ return new AnyOperand(clazz);
+ }
+
+ /** Creates an operand that matches a relational expression in the query. */
+ protected static Operand query(int ordinal) {
+ return new QueryOperand(ordinal);
+ }
+
+ /** Creates an operand that matches a relational expression in the
+ * target. */
+ protected static Operand target(int ordinal) {
+ return new TargetOperand(ordinal);
+ }
+ }
+
+ /** Implementation of {@link UnifyRule} that matches if the query is already
+ * equal to the target.
+ *
+ * <p>Matches scans to the same table, because these will be
+ * {@link MutableScan}s with the same
+ * {@link org.apache.calcite.rel.logical.LogicalTableScan} instance.</p>
+ */
+ private static class TrivialRule extends AbstractUnifyRule {
+ private static final TrivialRule INSTANCE = new TrivialRule();
+
+ private TrivialRule() {
+ super(any(MutableRel.class), any(MutableRel.class), 0);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ if (call.query.equals(call.target)) {
+ return call.result(call.query);
+ }
+ return null;
+ }
+ }
+
+ /** Implementation of {@link UnifyRule} that matches
+ * {@link org.apache.calcite.rel.logical.LogicalTableScan}. */
+ private static class ScanToProjectUnifyRule extends AbstractUnifyRule {
+ public static final ScanToProjectUnifyRule INSTANCE =
+ new ScanToProjectUnifyRule();
+
+ private ScanToProjectUnifyRule() {
+ super(any(MutableScan.class),
+ any(MutableProject.class), 0);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ final MutableProject target = (MutableProject) call.target;
+ final MutableScan query = (MutableScan) call.query;
+ // We do not need to check query's parent type to avoid duplication
+ // of ProjectToProjectUnifyRule or FilterToProjectUnifyRule, since
+ // SubstitutionVisitor performs a top-down match.
+ if (!query.equals(target.getInput())) {
+ return null;
+ }
+ final RexShuttle shuttle = getRexShuttle(target);
+ final RexBuilder rexBuilder = target.cluster.getRexBuilder();
+ final List<RexNode> newProjects;
+ try {
+ newProjects = (List<RexNode>)
+ shuttle.apply(rexBuilder.identityProjects(query.getRowType()));
+ } catch (MatchFailed e) {
+ return null;
+ }
+ final MutableProject newProject =
+ MutableProject.of(
+ query.getRowType(), target, newProjects);
+ final MutableRel newProject2 = MutableRels.strip(newProject);
+ return call.result(newProject2);
+ }
+ }
+
+ /** Implementation of {@link UnifyRule} that matches
+ * {@link org.apache.calcite.rel.logical.LogicalProject}. */
+ private static class ProjectToProjectUnifyRule extends AbstractUnifyRule {
+ public static final ProjectToProjectUnifyRule INSTANCE =
+ new ProjectToProjectUnifyRule();
+
+ private ProjectToProjectUnifyRule() {
+ super(operand(MutableProject.class, query(0)),
+ operand(MutableProject.class, target(0)), 1);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ final MutableProject target = (MutableProject) call.target;
+ final MutableProject query = (MutableProject) call.query;
+ final RexShuttle shuttle = getRexShuttle(target);
+ final List<RexNode> newProjects;
+ try {
+ newProjects = shuttle.apply(query.getProjects());
+ } catch (MatchFailed e) {
+ return null;
+ }
+ final MutableProject newProject =
+ MutableProject.of(
+ query.getRowType(), target, newProjects);
+ final MutableRel newProject2 = MutableRels.strip(newProject);
+ return call.result(newProject2);
+ }
+ }
+
+
+ /** Implementation of {@link UnifyRule} that matches a {@link MutableFilter}
+ * to a {@link MutableProject}. */
+ private static class FilterToProjectUnifyRule extends AbstractUnifyRule {
+ public static final FilterToProjectUnifyRule INSTANCE =
+ new FilterToProjectUnifyRule();
+
+ private FilterToProjectUnifyRule() {
+ super(operand(MutableFilter.class, query(0)),
+ operand(MutableProject.class, target(0)), 1);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ // Child of projectTarget is equivalent to child of filterQuery.
+ try {
+ // TODO: make sure that constants are ok
+ final MutableProject target = (MutableProject) call.target;
+ final RexShuttle shuttle = getRexShuttle(target);
+ final RexNode newCondition;
+ final MutableFilter query = (MutableFilter) call.query;
+ try {
+ newCondition = query.getCondition().accept(shuttle);
+ } catch (MatchFailed e) {
+ return null;
+ }
+ final MutableFilter newFilter = MutableFilter.of(target, newCondition);
+ if (query.parent instanceof MutableProject) {
+ final MutableRel inverse =
+ invert(((MutableProject) query.parent).getNamedProjects(),
+ newFilter, shuttle);
+ return call.create(query.parent).result(inverse);
+ } else {
+ final MutableRel inverse = invert(query, newFilter, target);
+ return call.result(inverse);
+ }
+ } catch (MatchFailed e) {
+ return null;
+ }
+ }
+
+ protected MutableRel invert(List<Pair<RexNode, String>> namedProjects,
+ MutableRel input,
+ RexShuttle shuttle) {
+ LOGGER.trace("SubstitutionVisitor: invert:\nprojects: {}\ninput: {}\nproject: {}\n",
+ namedProjects, input, shuttle);
+ final List<RexNode> exprList = new ArrayList<>();
+ final RexBuilder rexBuilder = input.cluster.getRexBuilder();
+ final List<RexNode> projects = Pair.left(namedProjects);
+ for (RexNode expr : projects) {
+ exprList.add(rexBuilder.makeZeroLiteral(expr.getType()));
+ }
+ for (Ord<RexNode> expr : Ord.zip(projects)) {
+ final RexNode node = expr.e.accept(shuttle);
+ if (node == null) {
+ throw MatchFailed.INSTANCE;
+ }
+ exprList.set(expr.i, node);
+ }
+ return MutableProject.of(input, exprList, Pair.right(namedProjects));
+ }
+
+ protected MutableRel invert(MutableRel model, MutableRel input,
+ MutableProject project) {
+ LOGGER.trace("SubstitutionVisitor: invert:\nmodel: {}\ninput: {}\nproject: {}\n",
+ model, input, project);
+ if (project.getProjects().size() < model.getRowType().getFieldCount()) {
+ throw MatchFailed.INSTANCE;
+ }
+ final List<RexNode> exprList = new ArrayList<>();
+ final RexBuilder rexBuilder = model.cluster.getRexBuilder();
+ for (RelDataTypeField field : model.getRowType().getFieldList()) {
+ exprList.add(rexBuilder.makeZeroLiteral(field.getType()));
+ }
+ for (Ord<RexNode> expr : Ord.zip(project.getProjects())) {
+ if (expr.e instanceof RexInputRef) {
+ final int target = ((RexInputRef) expr.e).getIndex();
+ exprList.set(target,
+ rexBuilder.ensureType(expr.e.getType(),
+ RexInputRef.of(expr.i, input.rowType),
+ false));
+ } else {
+ throw MatchFailed.INSTANCE;
+ }
+ }
+ return MutableProject.of(model.rowType, input, exprList);
+ }
+ }
+
+ /** Implementation of {@link UnifyRule} that matches a
+ * {@link MutableFilter}. */
+ private static class FilterToFilterUnifyRule extends AbstractUnifyRule {
+ public static final FilterToFilterUnifyRule INSTANCE =
+ new FilterToFilterUnifyRule();
+
+ private FilterToFilterUnifyRule() {
+ super(operand(MutableFilter.class, query(0)),
+ operand(MutableFilter.class, target(0)), 1);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ // in.query can be rewritten in terms of in.target if its condition
+ // is weaker. For example:
+ // query: SELECT * FROM t WHERE x = 1 AND y = 2
+ // target: SELECT * FROM t WHERE x = 1
+ // transforms to
+ // result: SELECT * FROM (target) WHERE y = 2
+ final MutableFilter query = (MutableFilter) call.query;
+ final MutableFilter target = (MutableFilter) call.target;
+ final MutableFilter newFilter =
+ createFilter(query, target);
+ if (newFilter == null) {
+ return null;
+ }
+ return call.result(newFilter);
+ }
+
+ MutableFilter createFilter(MutableFilter query, MutableFilter target) {
+ final RexNode newCondition =
+ splitFilter(query.cluster.getRexBuilder(), query.getCondition(),
+ target.getCondition());
+ if (newCondition == null) {
+ // Could not map query onto target.
+ return null;
+ }
+ if (newCondition.isAlwaysTrue()) {
+ return target;
+ }
+ return MutableFilter.of(target, newCondition);
+ }
+ }
+
+ /** Implementation of {@link UnifyRule} that matches a {@link MutableProject}
+ * to a {@link MutableFilter}. */
+ private static class ProjectToFilterUnifyRule extends AbstractUnifyRule {
+ public static final ProjectToFilterUnifyRule INSTANCE =
+ new ProjectToFilterUnifyRule();
+
+ private ProjectToFilterUnifyRule() {
+ super(operand(MutableProject.class, query(0)),
+ operand(MutableFilter.class, target(0)), 1);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ if (call.query.parent instanceof MutableFilter) {
+ final UnifyRuleCall in2 = call.create(call.query.parent);
+ final MutableFilter query = (MutableFilter) in2.query;
+ final MutableFilter target = (MutableFilter) in2.target;
+ final MutableFilter newFilter =
+ FilterToFilterUnifyRule.INSTANCE.createFilter(
+ query, target);
+ if (newFilter == null) {
+ return null;
+ }
+ return in2.result(query.replaceInParent(newFilter));
+ }
+ return null;
+ }
+ }
+
+ /** Implementation of {@link UnifyRule} that matches a
+ * {@link org.apache.calcite.rel.logical.LogicalAggregate} to a
+ * {@link org.apache.calcite.rel.logical.LogicalAggregate}, provided
+ * that they have the same child. */
+ private static class AggregateToAggregateUnifyRule extends AbstractUnifyRule {
+ public static final AggregateToAggregateUnifyRule INSTANCE =
+ new AggregateToAggregateUnifyRule();
+
+ private AggregateToAggregateUnifyRule() {
+ super(operand(MutableAggregate.class, query(0)),
+ operand(MutableAggregate.class, target(0)), 1);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ final MutableAggregate query = (MutableAggregate) call.query;
+ final MutableAggregate target = (MutableAggregate) call.target;
+ assert query != target;
+ // in.query can be rewritten in terms of in.target if its groupSet is
+ // a subset, and its aggCalls are a superset. For example:
+ // query: SELECT x, COUNT(b) FROM t GROUP BY x
+ // target: SELECT x, y, SUM(a) AS s, COUNT(b) AS cb FROM t GROUP BY x, y
+ // transforms to
+ // result: SELECT x, SUM(cb) FROM (target) GROUP BY x
+ if (!target.getGroupSet().contains(query.getGroupSet())) {
+ return null;
+ }
+ MutableRel result = unifyAggregates(query, target);
+ if (result == null) {
+ return null;
+ }
+ return call.result(result);
+ }
+ }
+
+ public static MutableAggregate permute(MutableAggregate aggregate,
+ MutableRel input, Mapping mapping) {
+ ImmutableBitSet groupSet = Mappings.apply(mapping, aggregate.getGroupSet());
+ ImmutableList<ImmutableBitSet> groupSets =
+ Mappings.apply2(mapping, aggregate.getGroupSets());
+ List<AggregateCall> aggregateCalls =
+ apply(mapping, aggregate.getAggCallList());
+ return MutableAggregate.of(input, aggregate.indicator, groupSet, groupSets,
+ aggregateCalls);
+ }
+
+ private static List<AggregateCall> apply(final Mapping mapping,
+ List<AggregateCall> aggCallList) {
+ return Lists.transform(aggCallList,
+ new Function<AggregateCall, AggregateCall>() {
+ public AggregateCall apply(AggregateCall call) {
+ return call.copy(Mappings.apply2(mapping, call.getArgList()),
+ Mappings.apply(mapping, call.filterArg));
+ }
+ });
+ }
+
+ public static MutableRel unifyAggregates(MutableAggregate query,
+ MutableAggregate target) {
+ if (query.getGroupType() != Aggregate.Group.SIMPLE
+ || target.getGroupType() != Aggregate.Group.SIMPLE) {
+ throw new AssertionError(Bug.CALCITE_461_FIXED);
+ }
+ MutableRel result;
+ if (query.getGroupSet().equals(target.getGroupSet())) {
+ // Same level of aggregation. Generate a project.
+ final List<Integer> projects = Lists.newArrayList();
+ final int groupCount = query.getGroupSet().cardinality();
+ for (int i = 0; i < groupCount; i++) {
+ projects.add(i);
+ }
+ for (AggregateCall aggregateCall : query.getAggCallList()) {
+ int i = target.getAggCallList().indexOf(aggregateCall);
+ if (i < 0) {
+ return null;
+ }
+ projects.add(groupCount + i);
+ }
+ result = MutableRels.createProject(target, projects);
+ } else {
+ // Target is coarser level of aggregation. Generate an aggregate.
+ final ImmutableBitSet.Builder groupSet = ImmutableBitSet.builder();
+ final List<Integer> targetGroupList = target.getGroupSet().asList();
+ for (int c : query.getGroupSet()) {
+ int c2 = targetGroupList.indexOf(c);
+ if (c2 < 0) {
+ return null;
+ }
+ groupSet.set(c2);
+ }
+ final List<AggregateCall> aggregateCalls = Lists.newArrayList();
+ for (AggregateCall aggregateCall : query.getAggCallList()) {
+ if (aggregateCall.isDistinct()) {
+ return null;
+ }
+ int i = target.getAggCallList().indexOf(aggregateCall);
+ if (i < 0) {
+ return null;
+ }
+ aggregateCalls.add(
+ AggregateCall.create(getRollup(aggregateCall.getAggregation()),
+ aggregateCall.isDistinct(),
+ ImmutableList.of(target.groupSet.cardinality() + i), -1,
+ aggregateCall.type, aggregateCall.name));
+ }
+ result = MutableAggregate.of(target, false, groupSet.build(), null,
+ aggregateCalls);
+ }
+ return MutableRels.createCastRel(result, query.getRowType(), true);
+ }
+
+ /** Implementation of {@link UnifyRule} that matches a
+ * {@link MutableAggregate} on
+ * a {@link MutableProject} query to an {@link MutableAggregate} target.
+ *
+ * <p>The rule is necessary when we unify query=Aggregate(x) with
+ * target=Aggregate(x, y). Query will tend to have an extra Project(x) on its
+ * input, which this rule knows is safe to ignore.</p> */
+ private static class AggregateOnProjectToAggregateUnifyRule
+ extends AbstractUnifyRule {
+ public static final AggregateOnProjectToAggregateUnifyRule INSTANCE =
+ new AggregateOnProjectToAggregateUnifyRule();
+
+ private AggregateOnProjectToAggregateUnifyRule() {
+ super(
+ operand(MutableAggregate.class,
+ operand(MutableProject.class, query(0))),
+ operand(MutableAggregate.class, target(0)), 1);
+ }
+
+ public UnifyResult apply(UnifyRuleCall call) {
+ final MutableAggregate query = (MutableAggregate) call.query;
+ final MutableAggregate target = (MutableAggregate) call.target;
+ if (!(query.getInput() instanceof MutableProject)) {
+ return null;
+ }
+ final MutableProject project = (MutableProject) query.getInput();
+ if (project.getInput() != target.getInput()) {
+ return null;
+ }
+ final Mappings.TargetMapping mapping = project.getMapping();
+ if (mapping == null) {
+ return null;
+ }
+ final MutableAggregate aggregate2 =
+ permute(query, project.getInput(), mapping.inverse());
+ final MutableRel result = unifyAggregates(aggregate2, target);
+ return result == null ? null : call.result(result);
+ }
+ }
+
+ public static SqlAggFunction getRollup(SqlAggFunction aggregation) {
+ if (aggregation == SqlStdOperatorTable.SUM
+ || aggregation == SqlStdOperatorTable.MIN
+ || aggregation == SqlStdOperatorTable.MAX
+ || aggregation == SqlStdOperatorTable.SUM0) {
+ return aggregation;
+ } else if (aggregation == SqlStdOperatorTable.COUNT) {
+ return SqlStdOperatorTable.SUM0;
+ } else {
+ return null;
+ }
+ }
+
+ /** Builds a shuttle that stores a list of expressions, and can map incoming
+ * expressions to references to them. */
+ protected static RexShuttle getRexShuttle(MutableProject target) {
+ final Map<String, Integer> map = new HashMap<>();
+ for (RexNode e : target.getProjects()) {
+ map.put(e.toString(), map.size());
+ }
+ return new RexShuttle() {
+ @Override public RexNode visitInputRef(RexInputRef ref) {
+ final Integer integer = map.get(ref.getName());
+ if (integer != null) {
+ return new RexInputRef(integer, ref.getType());
+ }
+ throw MatchFailed.INSTANCE;
+ }
+
+ @Override public RexNode visitCall(RexCall call) {
+ final Integer integer = map.get(call.toString());
+ if (integer != null) {
+ return new RexInputRef(integer, call.getType());
+ }
+ return super.visitCall(call);
+ }
+ };
+ }
+
+ /** Type of {@code MutableRel}. */
+ private enum MutableRelType {
+ SCAN,
+ PROJECT,
+ FILTER,
+ AGGREGATE,
+ SORT,
+ UNION,
+ JOIN,
+ HOLDER,
+ VALUES
+ }
+
+ /** Visitor over {@link MutableRel}. */
+ private static class MutableRelVisitor {
+ private MutableRel root;
+
+ public void visit(MutableRel node) {
+ node.childrenAccept(this);
+ }
+
+ public MutableRel go(MutableRel p) {
+ this.root = p;
+ visit(p);
+ return root;
+ }
+ }
+
+ /** Mutable equivalent of {@link RelNode}.
+ *
+ * <p>Each node has mutable state, and keeps track of its parent and position
+ * within parent.
+ * It doesn't make sense to canonize {@code MutableRels},
+ * otherwise one node could end up with multiple parents.
+ * It follows that {@code #hashCode} and {@code #equals} are less efficient
+ * than their {@code RelNode} counterparts.
+ * But, you don't need to copy a {@code MutableRel} in order to change it.
+ * For this reason, you should use {@code MutableRel} for short-lived
+ * operations, and transcribe back to {@code RelNode} when you are done.</p>
+ */
+ protected abstract static class MutableRel {
+ MutableRel parent;
+ int ordinalInParent;
+ public final RelOptCluster cluster;
+ final RelDataType rowType;
+ final MutableRelType type;
+
+ private MutableRel(RelOptCluster cluster, RelDataType rowType,
+ MutableRelType type) {
+ this.cluster = cluster;
+ this.rowType = rowType;
+ this.type = type;
+ }
+
+ public RelDataType getRowType() {
+ return rowType;
+ }
+
+ public abstract void setInput(int ordinalInParent, MutableRel input);
+
+ public abstract List<MutableRel> getInputs();
+
+ public abstract void childrenAccept(MutableRelVisitor visitor);
+
+ /** Replaces this {@code MutableRel} in its parent with another node at the
+ * same position.
+ *
+ * <p>Before the method, {@code child} must be an orphan (have null parent)
+ * and after this method, this {@code MutableRel} is an orphan.
+ *
+ * @return The parent
+ */
+ public MutableRel replaceInParent(MutableRel child) {
+ final MutableRel parent = this.parent;
+ if (this != child) {
+/*
+ if (child.parent != null) {
+ child.parent.setInput(child.ordinalInParent, null);
+ child.parent = null;
+ }
+*/
+ if (parent != null) {
+ parent.setInput(ordinalInParent, child);
+ this.parent = null;
+ this.ordinalInParent = 0;
+ }
+ }
+ return parent;
+ }
+
+ public abstract StringBuilder digest(StringBuilder buf);
+
+ public final String deep() {
+ return new MutableRelDumper().apply(this);
+ }
+
+ @Override public final String toString() {
+ return deep();
+ }
+
+ public MutableRel getParent() { return parent; }
+ }
+
+ /** Implementation of {@link MutableRel} whose only purpose is to have a
+ * child. Used as the root of a tree. */
+ private static class Holder extends MutableSingleRel {
+ private Holder(MutableRelType type, RelDataType rowType, MutableRel input) {
+ super(type, rowType, input);
+ }
+
+ static Holder of(MutableRel input) {
+ return new Holder(MutableRelType.HOLDER, input.rowType, input);
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Holder");
+ }
+ }
+
+ /** Abstract base class for implementations of {@link MutableRel} that have
+ * no inputs. */
+ protected abstract static class MutableLeafRel extends MutableRel {
+ protected final RelNode rel;
+
+ MutableLeafRel(MutableRelType type, RelNode rel) {
+ super(rel.getCluster(), rel.getRowType(), type);
+ this.rel = rel;
+ }
+
+ public void setInput(int ordinalInParent, MutableRel input) {
+ throw new IllegalArgumentException();
+ }
+
+ public List<MutableRel> getInputs() {
+ return ImmutableList.of();
+ }
+
+ public void childrenAccept(MutableRelVisitor visitor) {
+ // no children - nothing to do
+ }
+ }
+
+ /** Mutable equivalent of {@link SingleRel}. */
+ protected abstract static class MutableSingleRel extends MutableRel {
+ protected MutableRel input;
+
+ MutableSingleRel(MutableRelType type, RelDataType rowType,
+ MutableRel input) {
+ super(input.cluster, rowType, type);
+ this.input = input;
+ input.parent = this;
+ input.ordinalInParent = 0;
+ }
+
+ public void setInput(int ordinalInParent, MutableRel input) {
+ if (ordinalInParent >= 1) {
+ throw new IllegalArgumentException();
+ }
+ this.input = input;
+ if (input != null) {
+ input.parent = this;
+ input.ordinalInParent = 0;
+ }
+ }
+
+ public List<MutableRel> getInputs() {
+ return ImmutableList.of(input);
+ }
+
+ public void childrenAccept(MutableRelVisitor visitor) {
+ visitor.visit(input);
+ }
+
+ public MutableRel getInput() {
+ return input;
+ }
+ }
+
+ /** Mutable equivalent of
+ * {@link org.apache.calcite.rel.logical.LogicalTableScan}. */
+ protected static class MutableScan extends MutableLeafRel {
+ private MutableScan(TableScan rel) {
+ super(MutableRelType.SCAN, rel);
+ }
+
+ static MutableScan of(TableScan rel) {
+ return new MutableScan(rel);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableScan
+ && rel.getTable().equals(((MutableScan) obj).rel.getTable());
+ }
+
+ @Override public int hashCode() {
+ return rel.getTable().hashCode();
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Scan(table: ")
+ .append(rel.getTable().getQualifiedName()).append(")");
+ }
+ }
+
+ /** Mutable equivalent of {@link org.apache.calcite.rel.core.Values}. */
+ protected static class MutableValues extends MutableLeafRel {
+ private MutableValues(Values rel) {
+ super(MutableRelType.VALUES, rel);
+ }
+
+ static MutableValues of(Values rel) {
+ return new MutableValues(rel);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableValues
+ && rel == ((MutableValues) obj).rel;
+ }
+
+ @Override public int hashCode() {
+ return rel.hashCode();
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Values(tuples: ")
+ .append(((Values) rel).getTuples()).append(")");
+ }
+ }
+
+ /** Mutable equivalent of
+ * {@link org.apache.calcite.rel.logical.LogicalProject}. */
+ protected static class MutableProject extends MutableSingleRel {
+ private final List<RexNode> projects;
+
+ private MutableProject(RelDataType rowType, MutableRel input,
+ List<RexNode> projects) {
+ super(MutableRelType.PROJECT, rowType, input);
+ this.projects = projects;
+ assert RexUtil.compatibleTypes(projects, rowType, Litmus.THROW);
+ }
+
+ public static MutableProject of(RelDataType rowType, MutableRel input,
+ List<RexNode> projects) {
+ return new MutableProject(rowType, input, projects);
+ }
+
+ /** Equivalent to
+ * {@link RelOptUtil#createProject(org.apache.calcite.rel.RelNode, java.util.List, java.util.List)}
+ * for {@link MutableRel}. */
+ public static MutableRel of(MutableRel child, List<RexNode> exprList,
+ List<String> fieldNameList) {
+ final RelDataType rowType =
+ RexUtil.createStructType(child.cluster.getTypeFactory(), exprList,
+ fieldNameList, SqlValidatorUtil.F_SUGGESTER);
+ return of(rowType, child, exprList);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableProject
+ && PAIRWISE_STRING_EQUIVALENCE.equivalent(
+ projects, ((MutableProject) obj).projects)
+ && input.equals(((MutableProject) obj).input);
+ }
+
+ @Override public int hashCode() {
+ return Objects.hash(input,
+ PAIRWISE_STRING_EQUIVALENCE.hash(projects));
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Project(projects: ").append(projects).append(")");
+ }
+
+ public List<RexNode> getProjects() {
+ return projects;
+ }
+
+ /** Returns a list of (expression, name) pairs. */
+ public final List<Pair<RexNode, String>> getNamedProjects() {
+ return Pair.zip(getProjects(), getRowType().getFieldNames());
+ }
+
+ public Mappings.TargetMapping getMapping() {
+ return Project.getMapping(
+ input.getRowType().getFieldCount(), projects);
+ }
+ }
+
+ /** Mutable equivalent of
+ * {@link org.apache.calcite.rel.logical.LogicalFilter}. */
+ protected static class MutableFilter extends MutableSingleRel {
+ private final RexNode condition;
+
+ private MutableFilter(MutableRel input, RexNode condition) {
+ super(MutableRelType.FILTER, input.rowType, input);
+ this.condition = condition;
+ }
+
+ public static MutableFilter of(MutableRel input, RexNode condition) {
+ return new MutableFilter(input, condition);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableFilter
+ && condition.toString().equals(
+ ((MutableFilter) obj).condition.toString())
+ && input.equals(((MutableFilter) obj).input);
+ }
+
+ @Override public int hashCode() {
+ return Objects.hash(input, condition.toString());
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Filter(condition: ").append(condition).append(")");
+ }
+
+ public RexNode getCondition() {
+ return condition;
+ }
+ }
+
+ /** Mutable equivalent of
+ * {@link org.apache.calcite.rel.logical.LogicalAggregate}. */
+ protected static class MutableAggregate extends MutableSingleRel {
+ public final boolean indicator;
+ private final ImmutableBitSet groupSet;
+ private final ImmutableList<ImmutableBitSet> groupSets;
+ private final List<AggregateCall> aggCalls;
+
+ private MutableAggregate(MutableRel input, RelDataType rowType,
+ boolean indicator, ImmutableBitSet groupSet,
+ List<ImmutableBitSet> groupSets, List<AggregateCall> aggCalls) {
+ super(MutableRelType.AGGREGATE, rowType, input);
+ this.indicator = indicator;
+ this.groupSet = groupSet;
+ this.groupSets = groupSets == null
+ ? ImmutableList.of(groupSet)
+ : ImmutableList.copyOf(groupSets);
+ this.aggCalls = aggCalls;
+ }
+
+ static MutableAggregate of(MutableRel input, boolean indicator,
+ ImmutableBitSet groupSet, ImmutableList<ImmutableBitSet> groupSets,
+ List<AggregateCall> aggCalls) {
+ RelDataType rowType =
+ Aggregate.deriveRowType(input.cluster.getTypeFactory(),
+ input.getRowType(), indicator, groupSet, groupSets, aggCalls);
+ return new MutableAggregate(input, rowType, indicator, groupSet,
+ groupSets, aggCalls);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableAggregate
+ && groupSet.equals(((MutableAggregate) obj).groupSet)
+ && aggCalls.equals(((MutableAggregate) obj).aggCalls)
+ && input.equals(((MutableAggregate) obj).input);
+ }
+
+ @Override public int hashCode() {
+ return Objects.hash(input, groupSet, aggCalls);
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Aggregate(groupSet: ").append(groupSet)
+ .append(", groupSets: ").append(groupSets)
+ .append(", calls: ").append(aggCalls).append(")");
+ }
+
+ public ImmutableBitSet getGroupSet() {
+ return groupSet;
+ }
+
+ public ImmutableList<ImmutableBitSet> getGroupSets() {
+ return groupSets;
+ }
+
+ public List<AggregateCall> getAggCallList() {
+ return aggCalls;
+ }
+
+ public Aggregate.Group getGroupType() {
+ return Aggregate.Group.induce(groupSet, groupSets);
+ }
+ }
+
+ /** Mutable equivalent of {@link org.apache.calcite.rel.core.Sort}. */
+ protected static class MutableSort extends MutableSingleRel {
+ private final RelCollation collation;
+ private final RexNode offset;
+ private final RexNode fetch;
+
+ private MutableSort(MutableRel input, RelCollation collation,
+ RexNode offset, RexNode fetch) {
+ super(MutableRelType.SORT, input.rowType, input);
+ this.collation = collation;
+ this.offset = offset;
+ this.fetch = fetch;
+ }
+
+ static MutableSort of(MutableRel input, RelCollation collation,
+ RexNode offset, RexNode fetch) {
+ return new MutableSort(input, collation, offset, fetch);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableSort
+ && collation.equals(((MutableSort) obj).collation)
+ && Objects.equals(offset, ((MutableSort) obj).offset)
+ && Objects.equals(fetch, ((MutableSort) obj).fetch)
+ && input.equals(((MutableSort) obj).input);
+ }
+
+ @Override public int hashCode() {
+ return Objects.hash(input, collation, offset, fetch);
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ buf.append("Sort(collation: ").append(collation);
+ if (offset != null) {
+ buf.append(", offset: ").append(offset);
+ }
+ if (fetch != null) {
+ buf.append(", fetch: ").append(fetch);
+ }
+ return buf.append(")");
+ }
+ }
+
+ /** Base class for set-operations. */
+ protected abstract static class MutableSetOp extends MutableRel {
+ protected final List<MutableRel> inputs;
+
+ private MutableSetOp(RelOptCluster cluster, RelDataType rowType,
+ MutableRelType type, List<MutableRel> inputs) {
+ super(cluster, rowType, type);
+ this.inputs = inputs;
+ }
+
+ @Override public void setInput(int ordinalInParent, MutableRel input) {
+ inputs.set(ordinalInParent, input);
+ if (input != null) {
+ input.parent = this;
+ input.ordinalInParent = ordinalInParent;
+ }
+ }
+
+ @Override public List<MutableRel> getInputs() {
+ return inputs;
+ }
+
+ @Override public void childrenAccept(MutableRelVisitor visitor) {
+ for (MutableRel input : inputs) {
+ visitor.visit(input);
+ }
+ }
+ }
+
+ /** Mutable equivalent of
+ * {@link org.apache.calcite.rel.logical.LogicalUnion}. */
+ protected static class MutableUnion extends MutableSetOp {
+ public boolean all;
+
+ private MutableUnion(RelOptCluster cluster, RelDataType rowType,
+ List<MutableRel> inputs, boolean all) {
+ super(cluster, rowType, MutableRelType.UNION, inputs);
+ this.all = all;
+ }
+
+ static MutableUnion of(List<MutableRel> inputs, boolean all) {
+ assert inputs.size() >= 2;
+ final MutableRel input0 = inputs.get(0);
+ return new MutableUnion(input0.cluster, input0.rowType, inputs, all);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableUnion
+ && inputs.equals(((MutableUnion) obj).getInputs());
+ }
+
+ @Override public int hashCode() {
+ return Objects.hash(type, inputs);
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Union");
+ }
+ }
+
+ /** Base Class for relations with two inputs */
+ private abstract static class MutableBiRel extends MutableRel {
+ protected MutableRel left;
+ protected MutableRel right;
+
+ MutableBiRel(MutableRelType type, RelOptCluster cluster, RelDataType rowType,
+ MutableRel left, MutableRel right) {
+ super(cluster, rowType, type);
+ this.left = left;
+ left.parent = this;
+ left.ordinalInParent = 0;
+
+ this.right = right;
+ right.parent = this;
+ right.ordinalInParent = 1;
+ }
+
+ public void setInput(int ordinalInParent, MutableRel input) {
+ if (ordinalInParent > 1) {
+ throw new IllegalArgumentException();
+ }
+ if (ordinalInParent == 0) {
+ this.left = input;
+ } else {
+ this.right = input;
+ }
+ if (input != null) {
+ input.parent = this;
+ input.ordinalInParent = ordinalInParent;
+ }
+ }
+
+ public List<MutableRel> getInputs() {
+ return ImmutableList.of(left, right);
+ }
+
+ public MutableRel getLeft() {
+ return left;
+ }
+
+ public MutableRel getRight() {
+ return right;
+ }
+
+ public void childrenAccept(MutableRelVisitor visitor) {
+
+ visitor.visit(left);
+ visitor.visit(right);
+ }
+ }
+
+ /** Mutable equivalent of
+ * {@link org.apache.calcite.rel.logical.LogicalJoin}. */
+ private static class MutableJoin extends MutableBiRel {
+ //~ Instance fields --------------------------------------------------------
+
+ protected final RexNode condition;
+ protected final ImmutableSet<CorrelationId> variablesSet;
+
+ /**
+ * Values must be of enumeration {@link JoinRelType}, except that
+ * {@link JoinRelType#RIGHT} is disallowed.
+ */
+ protected JoinRelType joinType;
+
+ private MutableJoin(
+ RelDataType rowType,
+ MutableRel left,
+ MutableRel right,
+ RexNode condition,
+ JoinRelType joinType,
+ Set<CorrelationId> variablesSet) {
+ super(MutableRelType.JOIN, left.cluster, rowType, left, right);
+ this.condition = Preconditions.checkNotNull(condition);
+ this.variablesSet = ImmutableSet.copyOf(variablesSet);
+ this.joinType = Preconditions.checkNotNull(joinType);
+ }
+
+ public RexNode getCondition() {
+ return condition;
+ }
+
+ public JoinRelType getJoinType() {
+ return joinType;
+ }
+
+ public ImmutableSet<CorrelationId> getVariablesSet() {
+ return variablesSet;
+ }
+
+ static MutableJoin of(RelOptCluster cluster, MutableRel left,
+ MutableRel right, RexNode condition, JoinRelType joinType,
+ Set<CorrelationId> variablesStopped) {
+ List<RelDataTypeField> fieldList = Collections.emptyList();
+ RelDataType rowType =
+ SqlValidatorUtil.deriveJoinRowType(left.getRowType(),
+ right.getRowType(), joinType, cluster.getTypeFactory(), null,
+ fieldList);
+ return new MutableJoin(rowType, left, right, condition, joinType,
+ variablesStopped);
+ }
+
+ @Override public boolean equals(Object obj) {
+ return obj == this
+ || obj instanceof MutableJoin
+ && joinType == ((MutableJoin) obj).joinType
+ && condition.toString().equals(
+ ((MutableJoin) obj).condition.toString())
+ && left.equals(((MutableJoin) obj).left)
+ && right.equals(((MutableJoin) obj).right);
+ }
+
+ @Override public int hashCode() {
+ return Objects.hash(left, right, condition.toString(), joinType);
+ }
+
+ @Override public StringBuilder digest(StringBuilder buf) {
+ return buf.append("Join(left: ").append(left)
+ .append(", right:").append(right)
+ .append(")");
+ }
+ }
+
+ /** Utilities for dealing with {@link MutableRel}s. */
+ protected static class MutableRels {
+ public static boolean contains(MutableRel ancestor,
+ final MutableRel target) {
+ if (ancestor.equals(target)) {
+ // Short-cut common case.
+ return true;
+ }
+ try {
+ new MutableRelVisitor() {
+ @Override public void visit(MutableRel node) {
+ if (node.equals(target)) {
+ throw Util.FoundOne.NULL;
+ }
+ super.visit(node);
+ }
+ // CHECKSTYLE: IGNORE 1
+ }.go(ancestor);
+ return false;
+ } catch (Util.FoundOne e) {
+ return true;
+ }
+ }
+
+ public static MutableRel preOrderTraverseNext(MutableRel node) {
+ MutableRel parent = node.getParent();
+ int ordinal = node.ordinalInParent + 1;
+ while (parent != null) {
+ if (parent.getInputs().size() > ordinal) {
+ return parent.getInputs().get(ordinal);
+ }
+ node = parent;
+ parent = node.getParent();
+ ordinal = node.ordinalInParent + 1;
+ }
+ return null;
+ }
+
+ private static List<MutableRel> descendants(MutableRel query) {
+ final List<MutableRel> list = new ArrayList<>();
+ descendantsRecurse(list, query);
+ return list;
+ }
+
+ private static void descendantsRecurse(List<MutableRel> list,
+ MutableRel rel) {
+ list.add(rel);
+ for (MutableRel input : rel.getInputs()) {
+ descendantsRecurse(list, input);
+ }
+ }
+
+ /** Returns whether two relational expressions have the same row-type. */
+ public static boolean equalType(String desc0, MutableRel rel0, String desc1,
+ MutableRel rel1, Litmus litmus) {
+ return RelOptUtil.equal(desc0, rel0.getRowType(),
+ desc1, rel1.getRowType(), litmus);
+ }
+
+ /** Within a relational expression {@code query}, replaces occurrences of
+ * {@code find} with {@code replace}.
+ *
+ * <p>Assumes relational expressions (and their descendants) are not null.
+ * Does not handle cycles. */
+ public static Replacement replace(MutableRel query, MutableRel find,
+ MutableRel replace) {
+ if (find.equals(replace)) {
+ // Short-cut common case.
+ return null;
+ }
+ assert equalType("find", find, "replace", replace, Litmus.THROW);
+ return replaceRecurse(query, find, replace);
+ }
+
+ /** Helper for {@link #replace}. */
+ private static Replacement replaceRecurse(MutableRel query,
+ MutableRel find, MutableRel replace) {
+ if (find.equals(query)) {
+ query.replaceInParent(replace);
+ return new Replacement(query, replace);
+ }
+ for (MutableRel input : query.getInputs()) {
+ Replacement r = replaceRecurse(input, find, replace);
+ if (r != null) {
+ return r;
+ }
+ }
+ return null;
+ }
+
+ /** Based on
+ * {@link org.apache.calcite.rel.rules.ProjectRemoveRule#strip}. */
+ public static MutableRel strip(MutableProject project) {
+ return isTrivial(project) ? project.getInput() : project;
+ }
+
+ /** Based on
+ * {@link org.apache.calcite.rel.rules.ProjectRemoveRule#isTrivial(org.apache.calcite.rel.core.Project)}. */
+ public static boolean isTrivial(MutableProject project) {
+ MutableRel child = project.getInput();
+ final RelDataType childRowType = child.getRowType();
+ return RexUtil.isIdentity(project.getProjects(), childRowType);
+ }
+
+ /** Equivalent to
+ * {@link RelOptUtil#createProject(org.apache.calcite.rel.RelNode, java.util.List)}
+ * for {@link MutableRel}. */
+ public static MutableRel createProject(final MutableRel child,
+ final List<Integer> posList) {
+ final RelDataType rowType = child.getRowType();
+ if (Mappings.isIdentity(posList, rowType.getFieldCount())) {
+ return child;
+ }
+ return MutableProject.of(
+ RelOptUtil.permute(child.cluster.getTypeFactory(), rowType,
+ Mappings.bijection(posList)),
+ child,
+ new AbstractList<RexNode>() {
+ public int size() {
+ return posList.size();
+ }
+
+ public RexNode get(int index) {
+ final int pos = posList.get(index);
+ return RexInputRef.of(pos, rowType);
+ }
+ });
+ }
+
+ /** Equivalence to {@link org.apache.calcite.plan.RelOptUtil#createCastRel}
+ * for {@link MutableRel}. */
+ public static MutableRel createCastRel(MutableRel rel,
+ RelDataType castRowType, boolean rename) {
+ RelDataType rowType = rel.getRowType();
+ if (RelOptUtil.areRowTypesEqual(rowType, castRowType, rename)) {
+ // nothing to do
+ return rel;
+ }
+ List<RexNode> castExps =
+ RexUtil.generateCastExpressions(rel.cluster.getRexBuilder(),
+ castRowType, rowType);
+ final List<String> fieldNames =
+ rename ? castRowType.getFieldNames() : rowType.getFieldNames();
+ return MutableProject.of(rel, castExps, fieldNames);
+ }
+ }
+
+ /** Visitor that prints an indented tree of {@link MutableRel}s. */
+ protected static class MutableRelDumper extends MutableRelVisitor {
+ private final StringBuilder buf = new StringBuilder();
+ private int level;
+
+ @Override public void visit(MutableRel node) {
+ Spaces.append(buf, level * 2);
+ if (node == null) {
+ buf.append("null");
+ } else {
+ node.digest(buf);
+ buf.append("\n");
+ ++level;
+ super.visit(node);
+ --level;
+ }
+ }
+
+ public String apply(MutableRel rel) {
+ go(rel);
+ return buf.toString();
+ }
+ }
+
+ /** Returns if one rel is weaker than another. */
+ protected boolean isWeaker(MutableRel rel0, MutableRel rel) {
+ if (rel0 == rel || equivalents.get(rel0).contains(rel)) {
+ return false;
+ }
+
+ if (!(rel0 instanceof MutableFilter)
+ || !(rel instanceof MutableFilter)) {
+ return false;
+ }
+
+ if (!rel.getRowType().equals(rel0.getRowType())) {
+ return false;
+ }
+
+ final MutableRel rel0input = ((MutableFilter) rel0).getInput();
+ final MutableRel relinput = ((MutableFilter) rel).getInput();
+ if (rel0input != relinput
+ && !equivalents.get(rel0input).contains(relinput)) {
+ return false;
+ }
+
+ RexExecutorImpl rexImpl =
+ (RexExecutorImpl) (rel.cluster.getPlanner().getExecutor());
+ RexImplicationChecker rexImplicationChecker = new RexImplicationChecker(
+ rel.cluster.getRexBuilder(),
+ rexImpl, rel.getRowType());
+
+ return rexImplicationChecker.implies(((MutableFilter) rel0).getCondition(),
+ ((MutableFilter) rel).getCondition());
+ }
+
+ /** Operand to a {@link UnifyRule}. */
+ protected abstract static class Operand {
+ protected final Class<? extends MutableRel> clazz;
+
+ protected Operand(Class<? extends MutableRel> clazz) {
+ this.clazz = clazz;
+ }
+
+ public abstract boolean matches(SubstitutionVisitor visitor, MutableRel rel);
+
+ public boolean isWeaker(SubstitutionVisitor visitor, MutableRel rel) {
+ return false;
+ }
+ }
+
+ /** Operand to a {@link UnifyRule} that matches a relational expression of a
+ * given type. It has zero or more child operands. */
+ private static class InternalOperand extends Operand {
+ private final List<Operand> inputs;
+
+ InternalOperand(Class<? extends MutableRel> clazz, List<Operand> inputs) {
+ super(clazz);
+ this.inputs = inputs;
+ }
+
+ @Override public boolean matches(SubstitutionVisitor visitor, MutableRel rel) {
+ return clazz.isInstance(rel)
+ && allMatch(visitor, inputs, rel.getInputs());
+ }
+
+ @Override public boolean isWeaker(SubstitutionVisitor visitor, MutableRel rel) {
+ return clazz.isInstance(rel)
+ && allWeaker(visitor, inputs, rel.getInputs());
+ }
+ private static boolean allMatch(SubstitutionVisitor visitor,
+ List<Operand> operands, List<MutableRel> rels) {
+ if (operands.size() != rels.size()) {
+ return false;
+ }
+ for (Pair<Operand, MutableRel> pair : Pair.zip(operands, rels)) {
+ if (!pair.left.matches(visitor, pair.right)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ private static boolean allWeaker(
+ SubstitutionVisitor visitor,
+ List<Operand> operands, List<MutableRel> rels) {
+ if (operands.size() != rels.size()) {
+ return false;
+ }
+ for (Pair<Operand, MutableRel> pair : Pair.zip(operands, rels)) {
+ if (!pair.left.isWeaker(visitor, pair.right)) {
+ return false;
+ }
+ }
+ return true;
+ }
+ }
+
+ /** Operand to a {@link UnifyRule} that matches a relational expression of a
+ * given type. */
+ private static class AnyOperand extends Operand {
+ AnyOperand(Class<? extends MutableRel> clazz) {
+ super(clazz);
+ }
+
+ @Override public boolean matches(SubstitutionVisitor visitor, MutableRel rel) {
+ return clazz.isInstance(rel);
+ }
+ }
+
+ /** Operand that assigns a particular relational expression to a variable.
+ *
+ * <p>It is applied to a descendant of the query, writes the operand into the
+ * slots array, and always matches.
+ * There is a corresponding operand of type {@link TargetOperand} that checks
+ * whether its relational expression, a descendant of the target, is
+ * equivalent to this {@code QueryOperand}'s relational expression.
+ */
+ private static class QueryOperand extends Operand {
+ private final int ordinal;
+
+ protected QueryOperand(int ordinal) {
+ super(MutableRel.class);
+ this.ordinal = ordinal;
+ }
+
+ @Override public boolean matches(SubstitutionVisitor visitor, MutableRel rel) {
+ visitor.slots[ordinal] = rel;
+ return true;
+ }
+ }
+
+ /** Operand that checks that a relational expression matches the corresponding
+ * relational expression that was passed to a {@link QueryOperand}. */
+ private static class TargetOperand extends Operand {
+ private final int ordinal;
+
+ protected TargetOperand(int ordinal) {
+ super(MutableRel.class);
+ this.ordinal = ordinal;
+ }
+
+ @Override public boolean matches(SubstitutionVisitor visitor, MutableRel rel) {
+ final MutableRel rel0 = visitor.slots[ordinal];
+ assert rel0 != null : "QueryOperand should have been called first";
+ return rel0 == rel || visitor.equivalents.get(rel0).contains(rel);
+ }
+
+ @Override public boolean isWeaker(SubstitutionVisitor visitor, MutableRel rel) {
+ final MutableRel rel0 = visitor.slots[ordinal];
+ assert rel0 != null : "QueryOperand should have been called first";
+ return visitor.isWeaker(rel0, rel);
+ }
+ }
+
+ /** Visitor that counts how many {@link QueryOperand} and
+ * {@link TargetOperand} in an operand tree. */
+ private static class SlotCounter {
+ int queryCount;
+ int targetCount;
+
+ void visit(Operand operand) {
+ if (operand instanceof QueryOperand) {
+ ++queryCount;
+ } else if (operand instanceof TargetOperand) {
+ ++targetCount;
+ } else if (operand instanceof AnyOperand) {
+ // nothing
+ } else {
+ for (Operand input : ((InternalOperand) operand).inputs) {
+ visit(input);
+ }
+ }
+ }
+ }
+
+ /**
+ * Rule that converts a {@link org.apache.calcite.rel.logical.LogicalFilter}
+ * on top of a {@link org.apache.calcite.rel.logical.LogicalProject} into a
+ * trivial filter (on a boolean column).
+ */
+ public static class FilterOnProjectRule extends RelOptRule {
+ private static final Predicate<Filter> PREDICATE =
+ new Predicate<Filter>() {
+ public boolean apply(Filter input) {
+ return input.getCondition() instanceof RexInputRef;
+ }
+ };
+
+ public static final FilterOnProjectRule INSTANCE =
+ new FilterOnProjectRule();
+
+ private FilterOnProjectRule() {
+ super(
+ operand(Filter.class, null, PREDICATE,
+ some(operand(Project.class, any()))));
+ }
+
+ public void onMatch(RelOptRuleCall call) {
+ final Filter filter = call.rel(0);
+ final Project project = call.rel(1);
+
+ final List<RexNode> newProjects = new ArrayList<>(project.getProjects());
+ newProjects.add(filter.getCondition());
+
+ final RelOptCluster cluster = filter.getCluster();
+ RelDataType newRowType =
+ cluster.getTypeFactory().builder()
+ .addAll(project.getRowType().getFieldList())
+ .add("condition", Util.last(newProjects).getType())
+ .build();
+ final RelNode newProject =
+ project.copy(project.getTraitSet(),
+ project.getInput(),
+ newProjects,
+ newRowType);
+
+ final RexInputRef newCondition =
+ cluster.getRexBuilder().makeInputRef(newProject,
+ newProjects.size() - 1);
+
+ call.transformTo(filter.copy(filter.getTraitSet(), newProject, newCondition));
+ }
+ }
+}
+
+// End SubstitutionVisitor.java