private RelationPlan processAndCoerceIfNecessary(Relation node, Void context) { Type[] coerceToTypes = analysis.getRelationCoercion(node); RelationPlan plan = node.accept(this, context); if (coerceToTypes == null) { return plan; } List<Symbol> oldSymbols = plan.getOutputSymbols(); TupleDescriptor oldDescriptor = plan.getDescriptor().withOnlyVisibleFields(); verify(coerceToTypes.length == oldSymbols.size()); ImmutableList.Builder<Symbol> newSymbols = new ImmutableList.Builder<>(); Field[] newFields = new Field[coerceToTypes.length]; ImmutableMap.Builder<Symbol, Expression> assignments = new ImmutableMap.Builder<>(); for (int i = 0; i < coerceToTypes.length; i++) { Symbol inputSymbol = oldSymbols.get(i); Type inputType = symbolAllocator.getTypes().get(inputSymbol); Type outputType = coerceToTypes[i]; if (outputType != inputType) { Cast cast = new Cast( new QualifiedNameReference(inputSymbol.toQualifiedName()), outputType.getTypeSignature().toString()); Symbol outputSymbol = symbolAllocator.newSymbol(cast, outputType); assignments.put(outputSymbol, cast); newSymbols.add(outputSymbol); } else { assignments.put(inputSymbol, new QualifiedNameReference(inputSymbol.toQualifiedName())); newSymbols.add(inputSymbol); } Field oldField = oldDescriptor.getFieldByIndex(i); newFields[i] = new Field( oldField.getRelationAlias(), oldField.getName(), coerceToTypes[i], oldField.isHidden()); } ProjectNode projectNode = new ProjectNode(idAllocator.getNextId(), plan.getRoot(), assignments.build()); return new RelationPlan( projectNode, new TupleDescriptor(newFields), newSymbols.build(), plan.getSampleWeight()); }