xiedeyantu commented on code in PR #4540:
URL: https://github.com/apache/calcite/pull/4540#discussion_r2354444509
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core/src/main/java/org/apache/calcite/rel/metadata/RelMdFunctionalDependency.java:
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@@ -64,212 +76,445 @@ 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.findKeys(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) {
+ FunctionalDependencySet result = new FunctionalDependencySet();
+ for (RelNode input : inputs) {
+ FunctionalDependencySet fdSet = mq.getFunctionalDependencies(input);
+ result = result.union(fdSet);
Review Comment:
Perhaps this needs more rigor, as my initial thought was that `SetOp` and
`Join` operators were treated specially, while other multi-input operators
seemed to be left out. In fact, the current implementation should initially
prohibit multi-input operations, supporting only single input. If a
single-input `RelNode` has special cases (such as `Calc`), they should be
handled specially in `getFunctionalDependencies`. What do you think?
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