private RelationPlan planCrossJoinUnnest(RelationPlan leftPlan, Join joinNode, Unnest node) {
TupleDescriptor outputDescriptor = analysis.getOutputDescriptor(joinNode);
TupleDescriptor unnestOutputDescriptor = analysis.getOutputDescriptor(node);
// Create symbols for the result of unnesting
ImmutableList.Builder<Symbol> unnestedSymbolsBuilder = ImmutableList.builder();
for (Field field : unnestOutputDescriptor.getVisibleFields()) {
Symbol symbol = symbolAllocator.newSymbol(field);
unnestedSymbolsBuilder.add(symbol);
}
ImmutableList<Symbol> unnestedSymbols = unnestedSymbolsBuilder.build();
// Add a projection for all the unnest arguments
PlanBuilder planBuilder = initializePlanBuilder(leftPlan);
planBuilder = appendProjections(planBuilder, node.getExpressions());
TranslationMap translations = planBuilder.getTranslations();
ProjectNode projectNode =
checkType(planBuilder.getRoot(), ProjectNode.class, "planBuilder.getRoot()");
ImmutableMap.Builder<Symbol, List<Symbol>> unnestSymbols = ImmutableMap.builder();
UnmodifiableIterator<Symbol> unnestedSymbolsIterator = unnestedSymbols.iterator();
for (Expression expression : node.getExpressions()) {
Type type = analysis.getType(expression);
Symbol inputSymbol = translations.get(expression);
if (type instanceof ArrayType) {
unnestSymbols.put(inputSymbol, ImmutableList.of(unnestedSymbolsIterator.next()));
} else if (type instanceof MapType) {
unnestSymbols.put(
inputSymbol,
ImmutableList.of(unnestedSymbolsIterator.next(), unnestedSymbolsIterator.next()));
} else {
throw new IllegalArgumentException("Unsupported type for UNNEST: " + type);
}
}
Optional<Symbol> ordinalitySymbol =
node.isWithOrdinality() ? Optional.of(unnestedSymbolsIterator.next()) : Optional.empty();
checkState(
!unnestedSymbolsIterator.hasNext(),
"Not all output symbols were matched with input symbols");
UnnestNode unnestNode =
new UnnestNode(
idAllocator.getNextId(),
projectNode,
leftPlan.getOutputSymbols(),
unnestSymbols.build(),
ordinalitySymbol);
return new RelationPlan(
unnestNode, outputDescriptor, unnestNode.getOutputSymbols(), Optional.empty());
}
@Override
public Void visitUnnest(UnnestNode node, Void context) {
if (node.getOrdinalitySymbol() == null) {
printNode(
node,
format("Unnest[%s]", node.getUnnestSymbols().keySet()),
NODE_COLORS.get(NodeType.UNNEST));
} else {
printNode(
node,
format("Unnest[%s (ordinality)]", node.getUnnestSymbols().keySet()),
NODE_COLORS.get(NodeType.UNNEST));
}
return node.getSource().accept(this, context);
}
@Override
public PlanNode visitUnnest(UnnestNode node, RewriteContext<Set<Symbol>> context) {
List<Symbol> replicateSymbols =
node.getReplicateSymbols()
.stream()
.filter(context.get()::contains)
.collect(toImmutableList());
Optional<Symbol> ordinalitySymbol = node.getOrdinalitySymbol();
if (ordinalitySymbol.isPresent() && !context.get().contains(ordinalitySymbol.get())) {
ordinalitySymbol = Optional.empty();
}
Map<Symbol, List<Symbol>> unnestSymbols = node.getUnnestSymbols();
ImmutableSet.Builder<Symbol> expectedInputs =
ImmutableSet.<Symbol>builder().addAll(replicateSymbols).addAll(unnestSymbols.keySet());
PlanNode source = context.rewrite(node.getSource(), expectedInputs.build());
return new UnnestNode(
node.getId(), source, replicateSymbols, unnestSymbols, ordinalitySymbol);
}
@Override
public ActualProperties visitUnnest(UnnestNode node, List<ActualProperties> inputProperties) {
Set<Symbol> passThroughInputs = ImmutableSet.copyOf(node.getReplicateSymbols());
return Iterables.getOnlyElement(inputProperties)
.translate(
column -> {
if (passThroughInputs.contains(column)) {
return Optional.of(column);
}
return Optional.empty();
});
}