(Lumira Desktop version 1.19 used)
In External DataSource option, there are back to back two calls made with preview and refresh modes at the time of data acquisition. It makes it architecturally expensive.
Imagine a web service which returns decent about of data (i.e. data intensive service). Single step of data acquisition in Lumira calls web service twice. First time when we press “Next” button on new dataset screen with 300 rows and previewmode and next time normal refresh mode. If we look at it from service publisher view point, then we have one unnecessary call is being made to server as a refresh mode at data acquisition step. High probability of not being acceptable by the source/customer.
Logically speaking it should be one call when we acquire data set and next subsequent calls as normal manually done refresh.
I don’t know the real reason behind SAP making it this way. Probably, it does the data sampling to determine the data types of columns with few rows and when “Next” button is pressed and it considers the complete data set on redundant refresh call later on “Create” Button.
There is a workaround through which we could avoid two calls but I would like to know the reason of its current working model.
I have already put-in an idea about this. If you agree then vote for the idea.
Expensive Architecture (Data Access Extension) : View Idea
Best Regards,
Mayank