Hello vilem 

You can achieve this with the help of structure for example you have two entities 

School - I'd ,name,address, country

Class - I'd , name ,Sid(SchoolId)

You want to show only 

School name and class name 

- So create one structure of this 

- in the server action add BL LOGIC DRAG agg. and give two source entity school and name automatically join happend on that

-  output of that agg. Pass to the server action output parameter which take as (structure (school name,class name)list)

Pass the mapping parameter to the structure so you will just get what ever you want to display instead of all field 

Hope this will help you.

Thanks and regards,

Akshay Deshpande

Hi,

First things first. Let a DBA analyse the view on your external database. Maybe performance improvements can be made in the external database.

Regards,

Daniel

Hi, let me please correct my question. In fact we need an entity or some object that would not contain its own data but only a join of some other entities. And once application ask for its data it would get real time data from the joined entities. We don't want to duplicate the data. Is it achievable in OutSystems?

BTW the reason of this request is not the performance of the view but a clumsy process of modifying the view (we have only read only access to DB and we must often ask DBA to recompile the view)

Thank you, Vilem

Hello Villan , 

yes its achievable , you can create one core for both application and filter on your requirement
Create three Application -
1)First application with Core modules(entity present and BL which you want to used in two application )
2)Second application(end user modules) (In this used first application reference)
3_Third Application (End user modules)  (In this used first application reference)

This above mention application as per arch. dashboard best rules

 
Second thing, whatever I mentioned in first post already mention in this link go through this link
Performance Best Practices - Queries - OutSystems