I have an accordion AJax Toolkit control which at header level displays a list of categories from datatable1 (a distinct list of categories) , and in the content section I want to display the details (possibly in a grid) from datatable2 (a list of all products and detail including category).
There are plenty of tutorials on how to achieve this.

However the tricky part is that I don't want to re-query the database on opening each header. I would rather the data is pre-filled for each detail section based on the category and just gets displayed.

What would be the best approach to this?