Examples with SetOperation com.facebook.presto.sql.tree.SetOperation used on opensource projects

Example 1 with SetOperation

use of com.facebook.presto.sql.tree.SetOperation in project presto by prestodb.

the class RelationPlanner method process.

private SetOperationPlan process(SetOperation node) {
    List<VariableReferenceExpression> outputs = null;
    ImmutableList.Builder<PlanNode> sources = ImmutableList.builder();
    ImmutableListMultimap.Builder<VariableReferenceExpression, VariableReferenceExpression> variableMapping = ImmutableListMultimap.builder();
    List<RelationPlan> subPlans = node.getRelations().stream().map(relation -> processAndCoerceIfNecessary(relation, null)).collect(toImmutableList());
    for (RelationPlan relationPlan : subPlans) {
        List<VariableReferenceExpression> childOutputVariables = relationPlan.getFieldMappings();
        if (outputs == null) {
            // Use the first Relation to derive output variable names
            RelationType descriptor = relationPlan.getDescriptor();
            ImmutableList.Builder<VariableReferenceExpression> outputVariableBuilder = ImmutableList.builder();
            for (Field field : descriptor.getVisibleFields()) {
                int fieldIndex = descriptor.indexOf(field);
                VariableReferenceExpression variable = childOutputVariables.get(fieldIndex);
                outputVariableBuilder.add(variableAllocator.newVariable(variable));
            }
            outputs = outputVariableBuilder.build();
        }
        RelationType descriptor = relationPlan.getDescriptor();
        checkArgument(descriptor.getVisibleFieldCount() == outputs.size(), "Expected relation to have %s variables but has %s variables", descriptor.getVisibleFieldCount(), outputs.size());
        int fieldId = 0;
        for (Field field : descriptor.getVisibleFields()) {
            int fieldIndex = descriptor.indexOf(field);
            variableMapping.put(outputs.get(fieldId), childOutputVariables.get(fieldIndex));
            fieldId++;
        }
        sources.add(relationPlan.getRoot());
    }
    return new SetOperationPlan(sources.build(), variableMapping.build());
}