silundong commented on code in PR #4540:
URL: https://github.com/apache/calcite/pull/4540#discussion_r2378621304
##########
core/src/main/java/org/apache/calcite/rel/metadata/RelMdFunctionalDependency.java:
##########
@@ -64,212 +78,361 @@ protected RelMdFunctionalDependency() {}
return BuiltInMetadata.FunctionalDependency.DEF;
}
+ /**
+ * Determines if column is functionally dependent on key for a given rel
node.
+ */
public @Nullable Boolean determines(RelNode rel, RelMetadataQuery mq,
int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ return determinesSet(rel, mq, ImmutableBitSet.of(key),
ImmutableBitSet.of(column));
}
- public @Nullable Boolean determines(SetOp rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ /**
+ * Determines if a set of columns functionally determines another set of
columns.
+ */
+ public Boolean determinesSet(RelNode rel, RelMetadataQuery mq,
+ ImmutableBitSet determinants, ImmutableBitSet dependents) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(rel);
+ return fdSet.implies(determinants, dependents);
}
- public @Nullable Boolean determines(Join rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ /**
+ * Returns the closure of a set of columns under all functional dependencies.
+ */
+ public ImmutableBitSet closure(RelNode rel, RelMetadataQuery mq,
ImmutableBitSet attrs) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(rel);
+ return fdSet.closure(attrs);
}
- public @Nullable Boolean determines(Correlate rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ /**
+ * Returns candidate keys for the relation within the specified set of
attributes.
+ */
+ public Set<ImmutableBitSet> candidateKeys(
+ RelNode rel, RelMetadataQuery mq, ImmutableBitSet attributes) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(rel);
+ return fdSet.findCandidateKeys(attributes);
}
- public @Nullable Boolean determines(Aggregate rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl(rel, mq, key, column);
+ /**
+ * Main dispatch method for getFunctionalDependencies.
+ * Routes to appropriate handler based on RelNode type.
+ */
+ public FunctionalDependencySet getFunctionalDependencies(RelNode rel,
RelMetadataQuery mq) {
+ if (rel instanceof TableScan) {
+ return getTableScanFD((TableScan) rel);
+ } else if (rel instanceof Project) {
+ return getProjectFD((Project) rel, mq);
+ } else if (rel instanceof Aggregate) {
+ return getAggregateFD((Aggregate) rel, mq);
+ } else if (rel instanceof Join) {
+ return getJoinFD((Join) rel, mq);
+ } else if (rel instanceof Calc) {
+ return getCalcFD((Calc) rel, mq);
+ } else if (rel instanceof Filter) {
+ return getFilterFD((Filter) rel, mq);
+ } else if (rel instanceof SetOp) {
+ // TODO: Handle UNION, INTERSECT, EXCEPT functional dependencies
+ return new FunctionalDependencySet();
+ } else if (rel instanceof Correlate) {
+ // TODO: Handle CORRELATE functional dependencies
+ return new FunctionalDependencySet();
+ }
+ return getFD(rel.getInputs(), mq);
}
- public @Nullable Boolean determines(Calc rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl(rel, mq, key, column);
+ private static FunctionalDependencySet getFD(List<RelNode> inputs,
RelMetadataQuery mq) {
+ if (inputs.size() > 1) {
+ // Conservative approach for multi-input nodes without specific logic
+ return new FunctionalDependencySet();
+ }
+ return mq.getFunctionalDependencies(inputs.get(0));
}
- public @Nullable Boolean determines(Project rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl(rel, mq, key, column);
+ private static FunctionalDependencySet getTableScanFD(TableScan rel) {
+ FunctionalDependencySet fdSet = new FunctionalDependencySet();
+
+ RelOptTable table = rel.getTable();
+ List<ImmutableBitSet> keys = table.getKeys();
+ if (keys == null || keys.isEmpty()) {
+ return fdSet;
+ }
+
+ for (ImmutableBitSet key : keys) {
+ ImmutableBitSet allColumns =
ImmutableBitSet.range(rel.getRowType().getFieldCount());
+ ImmutableBitSet dependents = allColumns.except(key);
+ if (!dependents.isEmpty()) {
+ fdSet.addFD(key, dependents);
+ }
+ }
+
+ return fdSet;
+ }
+
+ private static FunctionalDependencySet getProjectFD(Project rel,
RelMetadataQuery mq) {
+ return getProjectionFD(rel.getInput(), rel.getProjects(), mq);
}
/**
- * Checks if a column is functionally determined by a key column through
expression analysis.
+ * Common method to compute functional dependencies for projection
operations.
+ * Used by both Project and Calc nodes.
*
- * @param rel The input relation
- * @param mq Metadata query instance
- * @param key Index of the determinant expression
- * @param column Index of the dependent expression
- * @return TRUE if column is determined by key,
- * FALSE if not determined,
- * NULL if undetermined
+ * @param input the input relation
+ * @param projections the list of projection expressions
+ * @param mq the metadata query
+ * @return the functional dependency set for the projection
*/
- private static @Nullable Boolean determinesImpl(RelNode rel,
RelMetadataQuery mq,
- int key, int column) {
- if (preCheck(rel, key, column)) {
- return true;
- }
-
- ImmutableBitSet keyInputIndices = null;
- ImmutableBitSet columnInputIndices = null;
- if (rel instanceof Project || rel instanceof Calc) {
- List<RexNode> exprs = null;
- if (rel instanceof Project) {
- Project project = (Project) rel;
- exprs = project.getProjects();
- } else {
- Calc calc = (Calc) rel;
- final RexProgram program = calc.getProgram();
- exprs = program.expandList(program.getProjectList());
+ private static FunctionalDependencySet getProjectionFD(
+ RelNode input, List<RexNode> projections, RelMetadataQuery mq) {
+ FunctionalDependencySet inputFdSet = mq.getFunctionalDependencies(input);
+ FunctionalDependencySet projectionFdSet = new FunctionalDependencySet();
+
+ // Create mapping from input column indices to project column indices
+ Mappings.TargetMapping inputToOutputMap =
+ RelOptUtil.permutation(projections, input.getRowType()).inverse();
+
+ // Map input functional dependencies to project dependencies
+ mapInputFDs(inputFdSet, inputToOutputMap, projectionFdSet);
+
+ int fieldCount = projections.size();
+ final ImmutableBitSet[] inputBits = new ImmutableBitSet[fieldCount];
+ final Map<RexNode, Integer> uniqueExprToIndex = new HashMap<>();
+ final Map<RexLiteral, Integer> literalToIndex = new HashMap<>();
+ final Map<RexInputRef, Integer> refToIndex = new HashMap<>();
+ for (int i = 0; i < fieldCount; i++) {
+ RexNode expr = projections.get(i);
+
+ // Skip non-deterministic expressions
+ if (!RexUtil.isDeterministic(expr)) {
+ continue;
}
- // TODO: Supports dependency analysis for all types of expressions
- if (!(exprs.get(column) instanceof RexInputRef)) {
- return false;
+ // Handle identical expressions in the projection list
+ Integer prev = uniqueExprToIndex.putIfAbsent(expr, i);
+ if (prev != null) {
+ projectionFdSet.addBidirectionalFD(prev, i);
}
- RexNode keyExpr = exprs.get(key);
- RexNode columnExpr = exprs.get(column);
-
- // Identical expressions imply functional dependency
- if (keyExpr.equals(columnExpr)) {
- return true;
+ // Track literal constants to handle them specially
+ if (expr instanceof RexLiteral) {
+ literalToIndex.put((RexLiteral) expr, i);
+ continue;
}
- keyInputIndices = extractDeterministicRefs(keyExpr);
- columnInputIndices = extractDeterministicRefs(columnExpr);
- } else if (rel instanceof Aggregate) {
- Aggregate aggregate = (Aggregate) rel;
-
- int groupByCnt = aggregate.getGroupCount();
- if (key < groupByCnt && column >= groupByCnt) {
- return false;
+ if (expr instanceof RexInputRef) {
+ refToIndex.put((RexInputRef) expr, i);
+ inputBits[i] = ImmutableBitSet.of(((RexInputRef) expr).getIndex());
}
- keyInputIndices = extractDeterministicRefs(aggregate, key);
- columnInputIndices = extractDeterministicRefs(aggregate, column);
- } else {
- throw new UnsupportedOperationException("Unsupported RelNode type: "
- + rel.getClass().getSimpleName());
+ inputBits[i] = RelOptUtil.InputFinder.bits(expr);
}
- // Early return if invalid cases
- if (keyInputIndices.isEmpty()
- || columnInputIndices.isEmpty()) {
- return false;
+ // Remove literals from uniqueExprToIndex to avoid redundant processing
+ uniqueExprToIndex.keySet().removeIf(key -> key instanceof RexLiteral);
+
+ for (Map.Entry<RexNode, Integer> entry : uniqueExprToIndex.entrySet()) {
+ RexNode expr = entry.getKey();
+ Integer i = entry.getValue();
+
+ // All columns determine literals
+ literalToIndex.values()
+ .forEach(l -> projectionFdSet.addFD(ImmutableBitSet.of(i),
ImmutableBitSet.of(l)));
+
+ // Input columns determine identical expressions
+ refToIndex.forEach((k, v) -> {
+ ImmutableBitSet refIndex = ImmutableBitSet.of(k.getIndex());
+ ImmutableBitSet bitSet = expr instanceof RexInputRef
+ ? ImmutableBitSet.of(((RexInputRef) expr).getIndex())
+ : inputBits[i];
+ if (inputFdSet.implies(refIndex, bitSet)) {
+ projectionFdSet.addFD(v, i);
+ }
+ });
}
- // Currently only supports multiple (keyInputIndices) to one
(columnInputIndices)
- // dependency detection
- for (Integer keyRef : keyInputIndices) {
- if (Boolean.FALSE.equals(
- mq.determines(rel.getInput(0), keyRef,
- columnInputIndices.nextSetBit(0)))) {
- return false;
+ return projectionFdSet;
+ }
+
+ /**
+ * Maps input functional dependencies to output dependencies based on column
mapping.
+ */
+ private static void mapInputFDs(FunctionalDependencySet inputFdSet,
+ Mappings.TargetMapping mapping, FunctionalDependencySet outputFdSet) {
+ for (FunctionalDependency inputFd : inputFdSet.getFDs()) {
+ ImmutableBitSet determinants = inputFd.getDeterminants();
+ ImmutableBitSet dependents = inputFd.getDependents();
+
+ // Skip this FD if any determinant column is unmappable
+ boolean allMappable =
+ determinants.stream().allMatch(col -> mapping.getTargetOpt(col) >=
0);
+ if (!allMappable) {
+ continue;
+ }
+
+ // Map all determinant columns
+ ImmutableBitSet mappedDeterminants = mapAllCols(determinants, mapping);
+ if (mappedDeterminants.isEmpty()) {
+ continue;
+ }
+
+ // Map only the dependent columns that can be mapped
+ ImmutableBitSet mappedDependents = mapAvailableCols(dependents, mapping);
+ if (!mappedDependents.isEmpty()) {
+ outputFdSet.addFD(mappedDeterminants, mappedDependents);
}
}
+ }
- return true;
+ /**
+ * Maps all columns in the set. Returns empty set if any column cannot be
mapped.
+ */
+ private static ImmutableBitSet mapAllCols(
+ ImmutableBitSet columns, Mappings.TargetMapping mapping) {
+ ImmutableBitSet.Builder builder = ImmutableBitSet.builder();
+ for (int col : columns) {
+ int mappedCol = mapping.getTargetOpt(col);
+ if (mappedCol < 0) {
+ return ImmutableBitSet.of();
+ }
+ builder.set(mappedCol);
+ }
+ return builder.build();
}
/**
- * determinesImpl2is similar to determinesImpl, but it doesn't need to
handle the
- * mapping between output and input columns.
+ * Maps only the columns that can be mapped, ignoring unmappable ones.
*/
- private static @Nullable Boolean determinesImpl2(RelNode rel,
RelMetadataQuery mq,
- int key, int column) {
- if (preCheck(rel, key, column)) {
- return true;
+ private static ImmutableBitSet mapAvailableCols(
+ ImmutableBitSet columns, Mappings.TargetMapping mapping) {
+ ImmutableBitSet.Builder builder = ImmutableBitSet.builder();
+ for (int col : columns) {
+ int mappedCol = mapping.getTargetOpt(col);
+ if (mappedCol >= 0) {
+ builder.set(mappedCol);
+ }
}
+ return builder.build();
+ }
- if (rel instanceof TableScan) {
- TableScan tableScan = (TableScan) rel;
- RelOptTable table = tableScan.getTable();
- List<ImmutableBitSet> keys = table.getKeys();
- return keys != null
- && keys.size() == 1
- && keys.get(0).equals(ImmutableBitSet.of(column));
- } else if (rel instanceof Join) {
- Join join = (Join) rel;
- // TODO Considering column mapping based on equality conditions in join
- int leftFieldCnt = join.getLeft().getRowType().getFieldCount();
- if (key < leftFieldCnt && column < leftFieldCnt) {
- return mq.determines(join.getLeft(), key, column);
- } else if (key >= leftFieldCnt && column >= leftFieldCnt) {
- return mq.determines(join.getRight(), key - leftFieldCnt, column -
leftFieldCnt);
+ private static FunctionalDependencySet getAggregateFD(Aggregate rel,
RelMetadataQuery mq) {
+ FunctionalDependencySet fdSet = new FunctionalDependencySet();
+ FunctionalDependencySet inputFdSet =
mq.getFunctionalDependencies(rel.getInput());
+
+ // Group set columns in the output
+ ImmutableBitSet groupSet = rel.getGroupSet();
+
+ // 1. Preserve input FDs that only involve group columns
+ if (Aggregate.isSimple(rel)) {
+ for (FunctionalDependency inputFd : inputFdSet.getFDs()) {
+ ImmutableBitSet determinants = inputFd.getDeterminants();
+ ImmutableBitSet dependents = inputFd.getDependents();
+
+ // Only preserve if both determinants and dependents are within group
columns
+ if (groupSet.contains(determinants) && groupSet.contains(dependents)) {
+ fdSet.addFD(determinants, dependents);
+ }
}
- return false;
- } else if (rel instanceof Correlate) {
- // TODO Support Correlate.
- return false;
- } else if (rel instanceof SetOp) {
- // TODO Support SetOp
- return false;
}
- return mq.determines(rel.getInput(0), key, column);
+ // 2. Group keys determine all aggregate columns
+ if (!groupSet.isEmpty() && !rel.getAggCallList().isEmpty()) {
+ for (int i = rel.getGroupCount(); i < rel.getRowType().getFieldCount();
i++) {
+ fdSet.addFD(groupSet, ImmutableBitSet.of(i));
+ }
+ }
+
+ return fdSet;
}
- private static Boolean preCheck(RelNode rel, int key, int column) {
- verifyIndex(rel, key, column);
+ private static FunctionalDependencySet getFilterFD(Filter rel,
RelMetadataQuery mq) {
+ FunctionalDependencySet inputSet =
mq.getFunctionalDependencies(rel.getInput());
+ FunctionalDependencySet filterFdSet = new
FunctionalDependencySet(inputSet.getFDs());
+ addFDsFromEquiCondition(rel.getCondition(), filterFdSet);
+ return filterFdSet;
+ }
- // Equal index values indicate the same expression reference
- if (key == column) {
- return true;
+ private static FunctionalDependencySet getJoinFD(Join rel, RelMetadataQuery
mq) {
+ FunctionalDependencySet leftFdSet =
mq.getFunctionalDependencies(rel.getLeft());
+ FunctionalDependencySet rightFdSet =
mq.getFunctionalDependencies(rel.getRight());
+
+ int leftFieldCount = rel.getLeft().getRowType().getFieldCount();
+ JoinRelType joinType = rel.getJoinType();
+
+ switch (joinType) {
+ case INNER:
+ // Inner join: preserve all FDs and derive cross-table dependencies
+ FunctionalDependencySet innerJoinFdSet
+ = leftFdSet.union(shiftFdSet(rightFdSet, leftFieldCount));
+ addFDsFromEquiCondition(rel.getCondition(), innerJoinFdSet);
+ return innerJoinFdSet.computeTransitiveClosure();
+ case LEFT:
+ // Left join: preserve left FDs, right FDs may be invalidated by NULLs
+ FunctionalDependencySet leftJoinFdSet = new
FunctionalDependencySet(leftFdSet.getFDs());
+ addFDsFromEquiCondition(rel.getCondition(), leftJoinFdSet);
+ return leftJoinFdSet.computeTransitiveClosure();
+ case RIGHT:
+ // Right join: preserve right FDs, left FDs may be invalidated by NULLs
+ FunctionalDependencySet rightJoinFdSet = shiftFdSet(rightFdSet,
leftFieldCount);
+ addFDsFromEquiCondition(rel.getCondition(), rightJoinFdSet);
+ return rightJoinFdSet.computeTransitiveClosure();
+ case FULL:
+ // Full join: both sides may have NULLs, very conservative approach
+ return new FunctionalDependencySet();
+ case SEMI:
+ // Semi join: only left table columns in result, preserve left FDs only
+ return new FunctionalDependencySet(leftFdSet.getFDs());
+ case ANTI:
+ // Anti join: only left table columns in result, preserve left FDs only
+ return new FunctionalDependencySet(leftFdSet.getFDs());
+ default:
+ // Conservative fallback for unknown join types
+ return new FunctionalDependencySet();
}
+ }
- return false;
+ private static FunctionalDependencySet getCalcFD(Calc rel, RelMetadataQuery
mq) {
+ List<RexNode> projections =
rel.getProgram().expandList(rel.getProgram().getProjectList());
+ return getProjectionFD(rel.getInput(), projections, mq);
}
- private static void verifyIndex(RelNode rel, int... indices) {
- for (int index : indices) {
- if (index < 0 || index >= rel.getRowType().getFieldCount()) {
- throw new IndexOutOfBoundsException(
- "Column index " + index + " is out of bounds. "
- + "Valid range is [0, " + rel.getRowType().getFieldCount() +
")");
- }
+ private static FunctionalDependencySet shiftFdSet(FunctionalDependencySet
fdSet, int offset) {
+ FunctionalDependencySet shiftedFdSet = new FunctionalDependencySet();
+ for (FunctionalDependency fd : fdSet.getFunctionalDependencies()) {
+ ImmutableBitSet shiftedDeterminants = fd.getDeterminants().shift(offset);
+ ImmutableBitSet shiftedDependents = fd.getDependents().shift(offset);
+ shiftedFdSet.addFD(shiftedDeterminants, shiftedDependents);
}
+ return shiftedFdSet;
}
/**
- * Extracts input indices referenced by an output column in an Aggregate.
- * For group-by columns, returns the column index itself since they directly
- * reference input columns. For aggregate function columns, returns the input
- * column indices used by the aggregate call.
- *
- * @param aggregate The Aggregate relational expression to analyze
- * @param index Index of the output column in the Aggregate (0-based)
- * @return ImmutableBitSet of input column indices referenced by the output
column.
- * For group-by columns, returns a singleton set of the column index.
- * For aggregate columns, returns the argument indices of the
aggregate call.
+ * Extracts FDs from equality and AND conditions.
*/
- private static ImmutableBitSet extractDeterministicRefs(Aggregate aggregate,
int index) {
- int groupByCnt = aggregate.getGroupCount();
- if (index < groupByCnt) {
- return ImmutableBitSet.of(index);
+ private static void addFDsFromEquiCondition(RexNode condition,
FunctionalDependencySet result) {
+ if (!(condition instanceof RexCall)) {
+ return;
}
- List<AggregateCall> aggCalls = aggregate.getAggCallList();
- AggregateCall call = aggCalls.get(index - groupByCnt);
- return ImmutableBitSet.of(call.getArgList());
- }
-
- /**
- * Extracts input indices referenced by a deterministic RexNode expression.
- *
- * @param rex The expression to analyze
- * @return referenced input indices if deterministic
- */
- private static ImmutableBitSet extractDeterministicRefs(RexNode rex) {
- if (rex instanceof RexCall && !RexUtil.isDeterministic(rex)) {
- return ImmutableBitSet.of();
+ RexCall call = (RexCall) condition;
+ // Handle equality condition: col1 = col2 or col1 IS NOT DISTINCT FROM col2
+ if (call.getOperator().getKind() == SqlKind.EQUALS
+ || call.getOperator().getKind() == SqlKind.IS_NOT_DISTINCT_FROM) {
+ List<RexNode> operands = call.getOperands();
+ if (operands.size() == 2) {
+ RexNode left = operands.get(0);
+ RexNode right = operands.get(1);
+
+ if (left instanceof RexInputRef && right instanceof RexInputRef) {
+ int leftRef = ((RexInputRef) left).getIndex();
+ int rightRef = ((RexInputRef) right).getIndex();
+
+ result.addFD(ImmutableBitSet.of(leftRef),
ImmutableBitSet.of(rightRef));
+ result.addFD(ImmutableBitSet.of(rightRef),
ImmutableBitSet.of(leftRef));
Review Comment:
You defined `addBidirectionalFD` method, I think it can be used here
##########
core/src/main/java/org/apache/calcite/rel/metadata/FunctionalDependencySet.java:
##########
@@ -0,0 +1,403 @@
+/*
+ * 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.metadata;
+
+import org.apache.calcite.util.ImmutableBitSet;
+
+import com.google.common.collect.ImmutableSet;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * A set of functional dependencies with closure and minimal cover operations.
+ * This class implements standard algorithms for functional dependency
reasoning.
+ */
+public class FunctionalDependencySet {
+ // Maximum number of transitive closure iterations to prevent infinite loops
+ public static final int MAX_TRANSITIVE_CLOSURE_LOOPS = 10;
+ // Maximum number of attributes supported in closure computation
+ private static final int MAX_CLOSURE_ATTRS = 10000;
+
+ private final Set<FunctionalDependency> fdSet = new HashSet<>();
+
+ public FunctionalDependencySet() {}
+
+ public FunctionalDependencySet(Set<FunctionalDependency> fds) {
+ this.fdSet.addAll(fds);
+ }
+
+ public void addFD(FunctionalDependency fd) {
+ if (!fd.isTrivial()) {
+ fdSet.add(fd);
+ }
+ }
+
+ public void addFD(ImmutableBitSet determinants, ImmutableBitSet dependents) {
+ addFD(FunctionalDependency.of(determinants, dependents));
+ }
+
+ public void addBidirectionalFD(ImmutableBitSet determinants, ImmutableBitSet
dependents) {
+ addFD(determinants, dependents);
+ addFD(dependents, determinants);
+ }
+
+ public void addFD(int determinant, int dependent) {
+ addFD(ImmutableBitSet.of(determinant), ImmutableBitSet.of(dependent));
+ }
+
+ public void addBidirectionalFD(int determinant, int dependent) {
+ addFD(ImmutableBitSet.of(determinant), ImmutableBitSet.of(dependent));
+ addFD(ImmutableBitSet.of(dependent), ImmutableBitSet.of(determinant));
+ }
+
+ public void removeFD(FunctionalDependency fd) {
+ fdSet.remove(fd);
+ }
+
+ public Set<FunctionalDependency> getFDs() {
+ return Collections.unmodifiableSet(fdSet);
+ }
+
+ /**
+ * Returns an ImmutableBitSet containing all attribute indexes that appear
in any FD in the set.
+ */
+ public static ImmutableBitSet allAttributesFromFDs(FunctionalDependencySet
fds) {
+ ImmutableBitSet.Builder builder = ImmutableBitSet.builder();
+ Set<FunctionalDependency> fdSet = fds.getFDs();
+ for (FunctionalDependency fd : fdSet) {
+ builder.addAll(fd.getDeterminants());
+ builder.addAll(fd.getDependents());
+ }
+ return builder.build();
+ }
+
+ /**
+ * Computes the closure of a set of attributes under this functional
dependency set.
+ * The closure of X, denoted X+, is the set of all attributes that can be
functionally
+ * determined by X using the functional dependencies in this set and
+ * <a href="https://en.wikipedia.org/wiki/Armstrong%27s_axioms";>Armstrong's
axioms</a>
+ *
+ * @param attributes the input attribute set
+ * @return the closure of the input attributes
+ */
+ public ImmutableBitSet closure(ImmutableBitSet attributes) {
+ if (attributes.isEmpty()) {
+ return ImmutableBitSet.of();
+ }
+
+ if (attributes.cardinality() > MAX_CLOSURE_ATTRS) {
+ throw new IllegalArgumentException(
Review Comment:
When there are too many elements in `attributes`, it may not be necessary to
throw an exception. How about returning it itself?
##########
core/src/main/java/org/apache/calcite/rel/metadata/RelMdFunctionalDependency.java:
##########
@@ -64,212 +76,424 @@ protected RelMdFunctionalDependency() {}
return BuiltInMetadata.FunctionalDependency.DEF;
}
+ /**
+ * Determines if column is functionally dependent on key for a given rel
node.
+ */
public @Nullable Boolean determines(RelNode rel, RelMetadataQuery mq,
int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ return determinesSet(rel, mq, ImmutableBitSet.of(key),
ImmutableBitSet.of(column));
}
- public @Nullable Boolean determines(SetOp rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ /**
+ * Determines if a set of columns functionally determines another set of
columns.
+ */
+ public Boolean determinesSet(RelNode rel, RelMetadataQuery mq,
+ ImmutableBitSet determinants, ImmutableBitSet dependents) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(rel);
+ return fdSet.implies(determinants, dependents);
}
- public @Nullable Boolean determines(Join rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ /**
+ * Returns the closure of a set of columns under all functional dependencies.
+ */
+ public ImmutableBitSet closure(RelNode rel, RelMetadataQuery mq,
ImmutableBitSet attrs) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(rel);
+ return fdSet.closure(attrs);
}
- public @Nullable Boolean determines(Correlate rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl2(rel, mq, key, column);
+ /**
+ * Returns candidate keys for the relation within the specified set of
attributes.
+ */
+ public Set<ImmutableBitSet> candidateKeys(
+ RelNode rel, RelMetadataQuery mq, ImmutableBitSet attributes) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(rel);
+ return fdSet.findCandidateKeys(attributes);
}
- public @Nullable Boolean determines(Aggregate rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl(rel, mq, key, column);
+ /**
+ * Main dispatch method for getFunctionalDependencies.
+ * Routes to appropriate handler based on RelNode type.
+ */
+ public FunctionalDependencySet getFunctionalDependencies(RelNode rel,
RelMetadataQuery mq) {
+ if (rel instanceof TableScan) {
+ return getTableScanFD((TableScan) rel);
+ } else if (rel instanceof Project) {
+ return getProjectFD((Project) rel, mq);
+ } else if (rel instanceof Aggregate) {
+ return getAggregateFD((Aggregate) rel, mq);
+ } else if (rel instanceof Join) {
+ return getJoinFD((Join) rel, mq);
+ } else if (rel instanceof Calc) {
+ return getCalcFD((Calc) rel, mq);
+ } else if (rel instanceof SetOp) {
+ // TODO: Handle UNION, INTERSECT, EXCEPT functional dependencies
+ return new FunctionalDependencySet();
+ } else if (rel instanceof Correlate) {
+ // TODO: Handle CORRELATE functional dependencies
+ return new FunctionalDependencySet();
+ }
+ return getFD(rel.getInputs(), mq);
}
- public @Nullable Boolean determines(Calc rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl(rel, mq, key, column);
+ private static FunctionalDependencySet getFD(List<RelNode> inputs,
RelMetadataQuery mq) {
+ if (inputs.size() > 1) {
+ // Conservative approach for multi-input nodes without specific logic
+ return new FunctionalDependencySet();
+ }
+ return mq.getFunctionalDependencies(inputs.get(0));
}
- public @Nullable Boolean determines(Project rel, RelMetadataQuery mq,
- int key, int column) {
- return determinesImpl(rel, mq, key, column);
- }
+ private static FunctionalDependencySet getTableScanFD(TableScan rel) {
+ FunctionalDependencySet fdSet = new FunctionalDependencySet();
- /**
- * Checks if a column is functionally determined by a key column through
expression analysis.
- *
- * @param rel The input relation
- * @param mq Metadata query instance
- * @param key Index of the determinant expression
- * @param column Index of the dependent expression
- * @return TRUE if column is determined by key,
- * FALSE if not determined,
- * NULL if undetermined
- */
- private static @Nullable Boolean determinesImpl(RelNode rel,
RelMetadataQuery mq,
- int key, int column) {
- if (preCheck(rel, key, column)) {
- return true;
+ RelOptTable table = rel.getTable();
+ List<ImmutableBitSet> keys = table.getKeys();
+ if (keys == null || keys.isEmpty()) {
+ return fdSet;
}
- ImmutableBitSet keyInputIndices = null;
- ImmutableBitSet columnInputIndices = null;
- if (rel instanceof Project || rel instanceof Calc) {
- List<RexNode> exprs = null;
- if (rel instanceof Project) {
- Project project = (Project) rel;
- exprs = project.getProjects();
- } else {
- Calc calc = (Calc) rel;
- final RexProgram program = calc.getProgram();
- exprs = program.expandList(program.getProjectList());
+ for (ImmutableBitSet key : keys) {
+ ImmutableBitSet allColumns =
ImmutableBitSet.range(rel.getRowType().getFieldCount());
+ ImmutableBitSet dependents = allColumns.except(key);
+ if (!dependents.isEmpty()) {
+ fdSet.addFD(key, dependents);
}
+ }
- // TODO: Supports dependency analysis for all types of expressions
- if (!(exprs.get(column) instanceof RexInputRef)) {
- return false;
- }
+ return fdSet;
+ }
- RexNode keyExpr = exprs.get(key);
- RexNode columnExpr = exprs.get(column);
+ private static FunctionalDependencySet getProjectFD(Project rel,
RelMetadataQuery mq) {
+ return getProjectionFD(rel.getInput(), rel.getProjects(), mq);
+ }
- // Identical expressions imply functional dependency
- if (keyExpr.equals(columnExpr)) {
- return true;
+ /**
+ * Common method to compute functional dependencies for projection
operations.
+ * Used by both Project and Calc nodes.
+ *
+ * @param input the input relation
+ * @param projections the list of projection expressions
+ * @param mq the metadata query
+ * @return the functional dependency set for the projection
+ */
+ private static FunctionalDependencySet getProjectionFD(
+ RelNode input, List<RexNode> projections, RelMetadataQuery mq) {
+ FunctionalDependencySet inputFdSet = mq.getFunctionalDependencies(input);
+ FunctionalDependencySet projectionFdSet = new FunctionalDependencySet();
+ int fieldCount = projections.size();
+
+ // Create mapping from input column indices to project column indices
+ Mappings.TargetMapping inputToOutputMap =
+ RelOptUtil.permutation(projections, input.getRowType()).inverse();
+
+ // Map input functional dependencies to project dependencies
+ mapInputFDs(inputFdSet, inputToOutputMap, projectionFdSet);
+
+ for (int i = 0; i < fieldCount; i++) {
+ for (int j = i + 1; j < fieldCount; j++) {
+ RexNode expr1 = projections.get(i);
+ RexNode expr2 = projections.get(j);
+
+ // Handle identical expressions, they determine each other
+ if (expr1.equals(expr2) && RexUtil.isDeterministic(expr1)) {
+ projectionFdSet.addFD(i, j);
+ projectionFdSet.addFD(j, i);
+ continue;
+ }
+
+ // Handle literal constants, all columns determine literals
+ if (expr1 instanceof RexLiteral) {
+ projectionFdSet.addFD(j, i);
+ }
+ if (expr2 instanceof RexLiteral) {
+ projectionFdSet.addFD(i, j);
+ }
+
+ // For complex expressions, only allow FD if one side is RexInputRef
+ // and the other is a deterministic expression
+ if (RexUtil.isDeterministic(expr1) && RexUtil.isDeterministic(expr2)) {
+ boolean expr1IsInputRef = expr1 instanceof RexInputRef;
+ boolean expr2IsInputRef = expr2 instanceof RexInputRef;
+ if (expr1IsInputRef && expr2IsInputRef) {
+ // Both are input refs, check FD between them
+ int idx1 = ((RexInputRef) expr1).getIndex();
+ int idx2 = ((RexInputRef) expr2).getIndex();
+ if (inputFdSet.implies(ImmutableBitSet.of(idx1),
ImmutableBitSet.of(idx2))) {
+ projectionFdSet.addFD(i, j);
+ }
+ if (inputFdSet.implies(ImmutableBitSet.of(idx2),
ImmutableBitSet.of(idx1))) {
+ projectionFdSet.addFD(j, i);
+ }
+ } else {
+ // Only one side is input ref, the other is a deterministic expr
+ if (expr1IsInputRef) {
+ int idx1 = ((RexInputRef) expr1).getIndex();
+ ImmutableBitSet inputs2 = RelOptUtil.InputFinder.bits(expr2);
+ if (!inputs2.isEmpty() &&
inputFdSet.implies(ImmutableBitSet.of(idx1), inputs2)) {
+ projectionFdSet.addFD(i, j);
+ }
+ } else if (expr2IsInputRef) {
+ ImmutableBitSet inputs1 = RelOptUtil.InputFinder.bits(expr1);
+ int idx2 = ((RexInputRef) expr2).getIndex();
+ if (!inputs1.isEmpty() &&
inputFdSet.implies(ImmutableBitSet.of(idx2), inputs1)) {
+ projectionFdSet.addFD(j, i);
+ }
+ }
+ }
+ }
}
+ }
- keyInputIndices = extractDeterministicRefs(keyExpr);
- columnInputIndices = extractDeterministicRefs(columnExpr);
- } else if (rel instanceof Aggregate) {
- Aggregate aggregate = (Aggregate) rel;
+ return projectionFdSet;
+ }
- int groupByCnt = aggregate.getGroupCount();
- if (key < groupByCnt && column >= groupByCnt) {
- return false;
+ /**
+ * Maps input functional dependencies to output dependencies based on column
mapping.
+ */
+ private static void mapInputFDs(FunctionalDependencySet inputFdSet,
+ Mappings.TargetMapping mapping, FunctionalDependencySet outputFdSet) {
+ for (FunctionalDependency inputFd : inputFdSet.getFDs()) {
+ ImmutableBitSet determinants = inputFd.getDeterminants();
+ ImmutableBitSet dependents = inputFd.getDependents();
+
+ // Skip this FD if any determinant column is unmappable
+ boolean allMappable =
+ determinants.stream().allMatch(col -> mapping.getTargetOpt(col) >=
0);
+ if (!allMappable) {
+ continue;
}
- keyInputIndices = extractDeterministicRefs(aggregate, key);
- columnInputIndices = extractDeterministicRefs(aggregate, column);
- } else {
- throw new UnsupportedOperationException("Unsupported RelNode type: "
- + rel.getClass().getSimpleName());
- }
+ // Map all determinant columns
+ ImmutableBitSet mappedDeterminants = mapAllCols(determinants, mapping);
Review Comment:
I mean that `allMappable` does not need to be calculated, just keep the
`mappedDeterminants.isEmpty()`.
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