aggregateResult are not calculating in after insret trigger but they work fine in after update trigger.
However after insert all the records are available and I can able to print it in the log. 
I am seeing this first time. why aggregrate results are not avilable in after insert trigger ?
Giving log here for your reference.

Thanks in advance.


public static void Update_Forecasting_by_group(map<id,Monthly_Forecast__c> MapMontlyForecast ){
        if(Execonce_method2){
           Execonce_method2 = false;
           list<Forecast_by_group> List_ForcastbyGr = new list<Forecast_by_group>();
           map<string ,Forecast_by_group> map_ForcastbyGr = new map<string ,Forecast_by_group>();
           map<string,id> FBG_Key_id_map = new map<string,id>();
           list<Forecasting_By_Group__c> Upsert_list = new list<Forecasting_By_Group__c>();   
           set<string> Set_ProdGrpMkt = new set<string>();
           
           system.debug('==MapMontlyForecast.keyset()==' + MapMontlyForecast.keyset()); 
           
           for(Monthly_Forecast__c MFobj : [select id,Account_Product_Forecast__r.Product_Group_Marketing__c,Product_Group_Marketing__c, Forecast_for_Date__c, revenue__c, delta_revenue__c, Product_Name__c, Account_Name__c from Monthly_Forecast__c where id in : MapMontlyForecast.keyset()] ){
                 system.debug('== Monthly_Forecast__c field values ==' + MFobj);
                 if(MFobj.Account_Product_Forecast__r.Product_Group_Marketing__c != null ) 
                 Set_ProdGrpMkt.add(MFobj.Account_Product_Forecast__r.Product_Group_Marketing__c);
           }
           
            
           system.debug('==Set_ProdGrpMkt==' + Set_ProdGrpMkt );
           List<aggregateResult> results = [select sum(Revenue__c) Total_Revenue , SUM(Delta_Revenue__c) Total_Delta_Revenue, Product_Group_Marketing__c, Forecast_for_Date__c from Monthly_Forecast__c where (Forecast_for_Date__c = Last_N_Years:1 or Forecast_for_Date__c = this_year) and Product_Group_Marketing__c in : Set_ProdGrpMkt group by Product_Group_Marketing__c, Forecast_for_Date__c];
          //List<aggregateResult> results = [select sum(Revenue__c) Total_Revenue , SUM(Delta_Revenue__c) Total_Delta_Revenue, Product_Group_Marketing__c, Forecast_for_Date__c from Monthly_Forecast__c where Product_Group_Marketing__c != null group by Product_Group_Marketing__c, Forecast_for_Date__c]; 
           
           system.debug('==results==' + results);
           
           for(aggregateResult ar  : results){
                 List_ForcastbyGr.add(new Forecast_by_group( (double)ar.get('Total_Revenue'),(double)ar.get('Total_Delta_Revenue') , (string)ar.get('Product_Group_Marketing__c'), (date)ar.get('Forecast_for_Date__c')  ));
           } 
           
           system.debug('==List_ForcastbyGr==' + List_ForcastbyGr);
           
           for(Forecast_by_group FBGobj : List_ForcastbyGr){
             map_ForcastbyGr.put(FBGobj.Forecast_by_group_key,FBGobj);
           }
          
          system.debug('==map_ForcastbyGr==' + map_ForcastbyGr);
          
          for(Forecasting_By_Group__c FBGobj : [select id,Forecast_by_group_key__c from Forecasting_By_Group__c where Forecast_by_group_key__c in : map_ForcastbyGr.keyset()])
              FBG_Key_id_map.put(FBGobj.Forecast_by_group_key__c, FBGobj.id);
                        
         system.debug('==FBG_Key_id_map==' + FBG_Key_id_map);     
              
          for(string Key : map_ForcastbyGr.keyset()){
                system.debug('==Key==' + Key);  
                Forecast_by_group FBGOBJ =   map_ForcastbyGr.get(Key);
                if(FBG_Key_id_map.containskey(Key))
                   Upsert_list.add(new Forecasting_By_Group__c(id = FBG_Key_id_map.get(key), Total_Revenue__c = FBGOBJ.Total_Revenue, Total_Delta__c = FBGOBJ.Total_Delta_Revenue,Product_Group_Marketing__c = FBGOBJ.product_mkt_grp, Forecast_for_Date__c = FBGOBJ.forecast_date));
                else
                   Upsert_list.add(new Forecasting_By_Group__c(Total_Revenue__c = FBGOBJ.Total_Revenue, Total_Delta__c = FBGOBJ.Total_Delta_Revenue,Product_Group_Marketing__c = FBGOBJ.product_mkt_grp, Forecast_for_Date__c = FBGOBJ.forecast_date));
            }
          
          system.debug('==Upsert_list==' + Upsert_list);
          
              if(Upsert_list.size() > 0)
                 upsert Upsert_list;
        }
    }

Log :

10:18:58.0 (285221766)|USER_DEBUG|[77]|DEBUG|==MapMontlyForecast.keyset()=={a0T4F000000jXiUUAU, a0T4F000000jXiVUAU}
10:18:58.0 (285563121)|SOQL_EXECUTE_BEGIN|[79]|Aggregations:0|SELECT id, Account_Product_Forecast__r.Product_Group_Marketing__c, Product_Group_Marketing__c, Forecast_for_Date__c, revenue__c, delta_revenue__c, Product_Name__c, Account_Name__c FROM Monthly_Forecast__c 
10:18:58.0 (295157565)|SOQL_EXECUTE_END|[79]|Rows:2
10:18:58.0 (295594304)|USER_DEBUG|[80]|DEBUG|== Monthly_Forecast__c field values ==Monthly_Forecast__c:{Id=a0T4F000000jXiUUAU, Account_Product_Forecast__c=a2q4F000000NYSHQA4, Forecast_for_Date__c=2018-07-15 00:00:00, Revenue__c=9.7284, Delta_Revenue__c=0.0000, Product_Name__c=LXML-PB01-0040, Account_Name__c=THOUSAND LIGHTS LIGHTING (CHANGZHOU) LIMITED, CurrencyIsoCode=USD}
10:18:58.0 (295751548)|USER_DEBUG|[80]|DEBUG|== Monthly_Forecast__c field values ==Monthly_Forecast__c:{Id=a0T4F000000jXiVUAU, Account_Product_Forecast__c=a2q4F000000NYSHQA4, Forecast_for_Date__c=2018-08-15 00:00:00, Revenue__c=19.4568, Delta_Revenue__c=0.0000, Product_Name__c=LXML-PB01-0040, Account_Name__c=THOUSAND LIGHTS LIGHTING (CHANGZHOU) LIMITED, CurrencyIsoCode=USD}
10:18:58.0 (295831738)|USER_DEBUG|[86]|DEBUG|==Set_ProdGrpMkt=={Colors}
10:18:58.0 (298335806)|SOQL_EXECUTE_BEGIN|[87]|Aggregations:0|SELECT SUM(Revenue__c) Total_Revenue, SUM(Delta_Revenue__c) Total_Delta_Revenue, Product_Group_Marketing__c, Forecast_for_Date__c FROM Monthly_Forecast__c WHERE ((Forecast_for_Date__c = Last_N_Years:1 OR Forecast_for_Date__c = this_year) AND Product_Group_Marketing__c = :tmpVar1) GROUP BY Product_Group_Marketing__c, Forecast_for_Date__c
10:18:58.0 (345034833)|SOQL_EXECUTE_END|[87]|Rows:0
10:18:58.0 (345188715)|USER_DEBUG|[90]|DEBUG|==results==()  ----> here is nothing is calcuating.
10:18:58.0 (345266134)|USER_DEBUG|[96]|DEBUG|==List_ForcastbyGr==()
10:18:58.0 (345397915)|USER_DEBUG|[102]|DEBUG|==map_ForcastbyGr=={}
10:18:58.0 (345676009)|SOQL_EXECUTE_BEGIN|[104]|Aggregations:0|SELECT id, Forecast_by_group_key__c FROM Forecasting_By_Group__c 
10:18:58.0 (349200864)|SOQL_EXECUTE_END|[104]|Rows:0
10:18:58.0 (349389572)|USER_DEBUG|[107]|DEBUG|==FBG_Key_id_map=={}
10:18:58.0 (349486674)|USER_DEBUG|[118]|DEBUG|==Upsert_list==()