@Override
protected RelationPlan visitUnnest(Unnest node, Void context) {
TupleDescriptor descriptor = analysis.getOutputDescriptor(node);
ImmutableList.Builder<Symbol> outputSymbolsBuilder = ImmutableList.builder();
for (Field field : descriptor.getVisibleFields()) {
Symbol symbol = symbolAllocator.newSymbol(field);
outputSymbolsBuilder.add(symbol);
}
List<Symbol> unnestedSymbols = outputSymbolsBuilder.build();
// If we got here, then we must be unnesting a constant, and not be in a join (where there could
// be column references)
ImmutableList.Builder<Symbol> argumentSymbols = ImmutableList.builder();
ImmutableList.Builder<Expression> values = ImmutableList.builder();
ImmutableMap.Builder<Symbol, List<Symbol>> unnestSymbols = ImmutableMap.builder();
Iterator<Symbol> unnestedSymbolsIterator = unnestedSymbols.iterator();
for (Expression expression : node.getExpressions()) {
Object constantValue =
evaluateConstantExpression(expression, analysis.getCoercions(), metadata, session);
Type type = analysis.getType(expression);
values.add(LiteralInterpreter.toExpression(constantValue, type));
Symbol inputSymbol = symbolAllocator.newSymbol(expression, type);
argumentSymbols.add(inputSymbol);
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");
ValuesNode valuesNode =
new ValuesNode(
idAllocator.getNextId(),
argumentSymbols.build(),
ImmutableList.<List<Expression>>of(values.build()));
UnnestNode unnestNode =
new UnnestNode(
idAllocator.getNextId(),
valuesNode,
ImmutableList.<Symbol>of(),
unnestSymbols.build(),
ordinalitySymbol);
return new RelationPlan(unnestNode, descriptor, unnestedSymbols, Optional.empty());
}
@Override
protected RelationPlan visitValues(Values node, Void context) {
TupleDescriptor descriptor = analysis.getOutputDescriptor(node);
ImmutableList.Builder<Symbol> outputSymbolsBuilder = ImmutableList.builder();
for (Field field : descriptor.getVisibleFields()) {
Symbol symbol = symbolAllocator.newSymbol(field);
outputSymbolsBuilder.add(symbol);
}
ImmutableList.Builder<List<Expression>> rows = ImmutableList.builder();
for (Expression row : node.getRows()) {
ImmutableList.Builder<Expression> values = ImmutableList.builder();
if (row instanceof Row) {
List<Expression> items = ((Row) row).getItems();
for (int i = 0; i < items.size(); i++) {
Expression expression = items.get(i);
Object constantValue =
evaluateConstantExpression(expression, analysis.getCoercions(), metadata, session);
values.add(
LiteralInterpreter.toExpression(
constantValue, descriptor.getFieldByIndex(i).getType()));
}
} else {
Object constantValue =
evaluateConstantExpression(row, analysis.getCoercions(), metadata, session);
values.add(
LiteralInterpreter.toExpression(
constantValue, descriptor.getFieldByIndex(0).getType()));
}
rows.add(values.build());
}
ValuesNode valuesNode =
new ValuesNode(idAllocator.getNextId(), outputSymbolsBuilder.build(), rows.build());
return new RelationPlan(valuesNode, descriptor, outputSymbolsBuilder.build(), Optional.empty());
}