presto-main/src/main/java/io/prestosql/sql/planner/QueryPlanner.java/QueryPlanner/planQueryBody
class QueryPlanner:    private PlanBuilder planQueryBody(Query query)
    {
        RelationPlan relationPlan = new RelationPlanner(analysis, symbolAllocator, idAllocator, lambdaDeclarationToSymbolMap, metadata, session)
                .process(query.getQueryBody(), null);

        return planBuilderFor(relationPlan);
    }