Datatable filled in two times

hcha

Hi,
I use a Datatable filled by a JSon source returned by Ajax requests (server side processing).
As I can have a large amount of data (1 000 000 rows) I run a first query to retrieve 10 000 rows and display them nearly at once and in background I run a second query to get remaining rows.

I try to force the display of the loading message if the user scroll at the end of the datatable when only the first 10 000 rows are loaded. How can i do ?

And when remaining rows are displayed, the cursor is reset to the top of the datatable. I would like to keep the previous position, in case the user already scrolled among the 10 000 first rows...

Thanks for your help