AIRegistryExpr aiExprSvc = statementContext.getStatementAgentInstanceRegistry().getAgentInstanceExprService();
AIRegistryAggregation aiAggregationSvc = statementContext.getStatementAgentInstanceRegistry().getAgentInstanceAggregationService();
// allocate aggregation service
if (startResult.getOptionalAggegationService() != null) {
aiAggregationSvc.assignService(agentInstanceId, startResult.getOptionalAggegationService());
}
// allocate subquery
for (Map.Entry<ExprSubselectNode, SubSelectStrategyHolder> item : startResult.getSubselectStrategies().entrySet()) {
ExprSubselectNode node = item.getKey();