presto-main/src/main/java/io/prestosql/sql/planner/LocalExecutionPlanner.java/LocalExecutionPlanner/planGroupByAggregation
class LocalExecutionPlanner:        private PhysicalOperation planGroupByAggregation(
                AggregationNode node,
                PhysicalOperation source,
                boolean spillEnabled,
                DataSize unspillMemoryLimit,
                LocalExecutionPlanContext context)
        {
            ImmutableMap.Builder<Symbol, Integer> mappings = ImmutableMap.builder();
            OperatorFactory operatorFactory = createHashAggregationOperatorFactory(
                    node.getId(),
                    node.getAggregations(),
                    node.getGlobalGroupingSets(),
                    node.getGroupingKeys(),
                    node.getStep(),
                    node.getHashSymbol(),
                    node.getGroupIdSymbol(),
                    source,
                    node.hasDefaultOutput(),
                    spillEnabled,
                    node.isStreamable(),
                    unspillMemoryLimit,
                    context,
                    0,
                    mappings,
                    10_000,
                    Optional.of(maxPartialAggregationMemorySize),
                    node.getStep().isOutputPartial());
            return new PhysicalOperation(operatorFactory, mappings.build(), context, source);
        }