I have a 250 MM rows fact table (3 gb app and a 20 gb qvd) that I will transform in an on demand app generator.
First step was to split this huge qvd in month-year.qvd incremental load. That is done.
Also, I know how to create a summary and a template app using ODAG object.
My doubt is to know what is the best strategy to create the summary app without using the original 250 MM fact table (or all month-year.qvds). But without it I cant know how many rows are selected with the filters to set the trigger to generate the app.
I tried to create an auxiliar qvd with a group by with date, count(date) per qvd and load these auxiliar qvds in the summary app but its a slow group by and maybe there is another better strategy